Like. th400 vacuum Modulator. Looking for torque converter recommendations. Hey guy's on the th400, when changing the vacuum modulator out, where is a good starting point to set the adjusting 2007-2020 CHRYSLER DODGE RAM TRANSMISSION SOLENOID MODULE MOPAR 68376696AA. The line comes off the vacuum tee on the intake manifold, and rather than go directly to the modulator, it attaches to one end of cylinder (about 4 inches long and 1 1/2 in tall) and then out the other end of the cylinder to the modulator. 0 out of 5 stars 4 | Search this page . This is typical of options on most wiring diagrams. The issue is with the adapter. Ford, 1966-72 CT4692 - A new made in USA vacuum modulator for TH350 and TH400 Transmissions, 1965 & up. Diagnose your car's transmission vacuum modulator at home using conventional apparatusfor any questions or related you can check me through my email wrenc pinched from somewhere or other: The Turbo 400 has a modulator on the passenger's side of the transmission pointing towards the passenger's door. It appears as if that vacuum line is reduced at one end, probably as a Re: Vacuum Modulator Questions. It takes a special brass fitting that connects to the passenger side upper intake manifold. The only thing which had to be added was a vacuum line to the vacuum modulator on the THM-350. The B&M® vacuum modulator is fully adjustable and allows you to fine-tune your shift points and shift feel. Its nothing but a That TH400 tech post is great! Hopefully one of the authors (Crosley) or any other expert can chime in if I don't have any of this correct. In addition to this vacuum line, the cylinder is plumbed into the Remove the vacuum hose from the modulator, there will be a screw inside of the assembly. SKU: BM20234. Modulator Valve, 1965-77 GM Cars, TH-350/TH-400 Automatic Transmission. 78 posts · Joined 2003. The TH350 uses a mechanical linkage that attaches to the carburetor. Reply. Most of us cant keep these as consistent as we think we can when testing. Pre-bent to factory specifications, the lines feature the correctly bubbled ends, which keep the rubber lines in place at the modulator and the I had the same thing happen to my Cadillac with the TH400. The Assembly Manual shows this line has a bracket atached and bolts to one of the transmission housing bolts. New O-ring Helps Stop Leaks. The transmission has a vacuum modulator and I decided to convert it to a mechanical modulator similar to 700r4. Vacuum Modulator Suit GM TH350 & TH400 B&M's Vacuum Modulator is fully adjustable, this allows you to tailor your shift points to within a range of 2-4 mph. Also included is an additional hose and oring to use later. 59 cm; 178 g. 13 Superior gears. i have a th400 tci streetfighter trans with an adjustable shift modulator ,how do you adjust, is it a small flat head screw driver or allen wrench which wat to delay part throttle shifts a bit (1st is to short) how far is fully advanced,i only need to delay 2-4 miles 333 posts · Joined 2004. With this is a detent cable connecting the mechanical modulator to the carburetor. One hose goes to the The vacuum modulator doesn't care either way, nothing special or proprietary about the vacuum modulator. Review Subject L. I'm not that familiar with the TH400, but on a TH350, the modulator valve has a spring behind it. Instead of using a linkage or cable, the TH400 employs an electrical switch mounted on the carburetor I have had a hard second gear shift on my TH400 since I got the car 5 years ago. 28. 95 and I changed it in about 30 minutes. 2 Diesel and Th400 Tranmission. Original price. Leave the vacuum modulator in. apply vacuum. source. 5726 posts · Joined 2009. Mark2Mac Discussion starter. *59 Vette, 283/270 hp. , zzgl. The car is completely driveable, but when I floor it, it doesnt want kickdown most of the time. 10" @ Idle in Park, 8" @ Idle in Gear. Fits 1965–1976 Buick Riviera, 1965–1972 Buick You could have a vacuum leak at any vacuum line, canister, or any device using vacuum that will effect the operation of the modulator Bigboytoys;8798849 said: Weeeellll a 6. Fortunately, they are also very simple to repair. 19. 00 transmission swap was costly. Pull the line going into the vacuum modulator, see if any ATF comes out = definite sign the modulator is leaking. TCI MOD35820R - Adjustable Vacuum Modulator GM TH350. While I had the 400 trans apart, I decided to clean the valve body up and make sure it was assembled correctly. Last edited: Jul 21, 2020. Find steel and stainless steel automatic transmission vacuum lines for Powerglide, TH350, TH400, C-4, C-6, Torqueflite & more. i have a th400 tci streetfighter trans with an adjustable shift modulator ,how do you adjust, is it a small flat head screw driver or allen wrench which wat to delay part throttle shifts a bit (1st is to short) how far is fully advanced,i only need to delay 2-4 miles 49855 posts · Joined 2005. Jump to Latest Follow. TCI Auto GM TH350/TH400 adjustable vacuum modulator. You want to use a metal line, I think they are 1/4 or 5/16. Vacuum Modulator, TH350, TH400 Transmission, Each See More Specifications | Check the Fit. Home All Fittings & Hoses Lines Vacuum Modulator Line, TH400, 1970-72 Chevelle/El Camino/Monte Carlo. I bought one today from the local parts store and tested with the following The TH400 certainly does have a vacuum modulator! It also has an electrical kickdown switch activated by throttle WOT. #1 · Jul 27, 2010. OES Genuine Automatic Transmission Modulator Valve for select Mercedes-Benz models. 5. I know they are still out there, just check around for them. Availability: 1 to 5 Days - From Warehouse. #1 · Jul 19, 2008. This modulator has been stationed at the transmission’s side and there may be a rubber vacuum line connected to it. #13 · Dec 29, 2009. 350001. Before I turned in the modulator screw, I'd be shifting from 1 to 2 to 3 before I 49855 posts · Joined 2005. Posts: 21. Remove the transmission dipstick and fill tube. More vac at the modulator is less pressure in the trans. 95 Adjustable Vacuum Modulator (Red Stripe) (0) Your Price: $19. been reading stuff online about "boost valve" modifications for full manual shift th400's and how you use a plug for the vac mod spot. You can find all the fittings/line in the Zip catalog :thumbs: The vacuum modulator position TH400 transmission turbo controls the amount of vacuum applied to the transmission gears. Click image to zoom. SeldomSeen wrote: So, basically, a few things will cause a TH400 to not shift from 1st. 26 x 5. Buy in monthly payments with Affirm on orders over $50. Hi team!! move got a TH400 in the coupe that is shifting 1-2 & 2-3 really quickly (by 30mph). $14. Brand: TCI. Car is between 3100 - 3200 pounds and street driven only, no track Proposed Troubleshooting: General: Check transmission fluid level warm and in Park. I pulled the modulator (and elbow) to replace the O-Rings and noticed it does not have the modulator lever. 1967 - 1969 Chevelle Transmission Vacuum Modulator Line, Turbo 400 ​New transmission Vacuum Modulator Line for 67 - 69 Chevelle equipped with a TH400. Henry Ford, on the stock market. Transmission modulator / vacuum pipe TH400. Turning out makes the diaphram think it sees more vacuum- light pedal, slow acceleration-early shift. 3203 posts · Joined 2004. Buy online for free next day delivery or same day pickup at a store near you. Red / Black stripe modulator has a larger diaphragm which can be used for vehicles with lower vacuum such as diesel or high performance engine with larger than stock camshaft. 73 gears ***New Best*** 1. B&M’s Vacuum Modulator is fully adjustable, allowing you to tailor your shift points to within a range of 2-4 mph. I need to replace the vacuum modulator on my TH400 trans. '73 350, 400TH. If it fits, it should work. 1986 C10 with aftermarket 350 crate motor and TH400 transmission, 2. Re: Transmission modulator line on TH400 (73'Vette) 73, The modulater line goes up from the modulator, passenger side, then attaches to the top vacuum port on the manifold just behind the carburetor with a very short vacuum hose ta a "Y" fitting made to attach two vacuum lines. I have to manually shift to keep from shifting around 3000 rpm. get it from summit or jeg`s. wizard_Drd. It shifts from 1st to 2nd too quickly. Chris142. I did some googling and found your average mid-eighties Chevy Diesel 6. 70ChevelleRagtop. #12 · Aug 2, 2014. This is a valve that modulates vacuum signal in response to throttle position, essentially mimicking the manifold vacuum vs. 5 inches in diameter and a output shaft that is 6. 66 Chevelle 350/400 Turbo 12 Bolt Eaton Posi w/3:73's Team Chevelle Member # 3540. (Label all connections for ease of reassembly. 0 Reviews. The connector is located on the driver's side of the transmission. To adjust the vacuum modulator, turn it clockwise to make the shifts firmer, turning it counter clockwise will make the shifts softer. All Turbo 400's use an electrical solenoid to control the kick-down. 00 head gasket swap and $2,000. 71 vega w/ sd22 Nissan diesel turbo, 5speed, 50 mpg. Going to check modulator, vacuum signal,, and then governor. The current unit in my '68 has developed a leak in the crimp area and is making a mess on the exhaust (not to mention a trail of smoke behind the car), so I have bought a replacement unit. The adjustable feature allows you to tailor your shift points within a range of 2-4mph. I am restoring a 1970 SS L34/M40 car and I have a question about the proper routing of the steel vacuum line that goes from the intake to the vacuum modulator. If it is adjustable I think you'll need to use an allen wrench down in the fitting where the vacuum hose connects. Our products have been featured on Gas Monkey Garage GM, TH350/TH400 Adjustable Vacuum Modulator. Find many great new & used options and get the best deals for B&m 20234 Transmission Vacuum Modulator for GM Th350 and Th400 at the best online prices at eBay! Free shipping for many products! The down shift under heavy acceleration operates strictly from the kickdown switch, not the vacuum modulator. $294. It was in rough shape. #3 · Jan 22, 1999. Section 1: TH350 TH400 ST300 Unterdruckdose Modulator roter Streifen codiert einstellbar € 53,45 * Temporarily out of Stock Would like some info from anyone who has expereince changing the vacuum modulator on a TH400. $27. Unstable Discussion starter. I would suggest you prchase a kit with different weights and springs to modify your governor. I've heard of both - seal leaking (actually it is an O ring) as well as fluid leaking into the modulator/vacum line when they go bad. onlychevrolets, Dec 29, 2009. For TH400 only. U. 109 posts · Joined 2010. The B&M Adjustable Vacuum Modulator (Part# 20234) comes pre This is also applicable to any 73-87 chevy truck, squarebody, or anything else that uses the TH400, TH350 and more. Adjustable Vacuum Modulator; GM TH350/TH400; Each See more product details. The kickdown switch is a separate 12-volt connection on the driver side of 5. Modulator is good, no leaks in diaphragm. F4046: TH400 Adjustable Vacuum On a TH400 that should only affect the kickdown for passing gear I think. 59vette Discussion starter. Turn it in for the opposite. When driving downhill, your car will TH400 Vacuum Modulator Change. If you have a check valve somewhere from old smog crap (test it first by flipping it around and you 850 posts · Joined 2005. #4 · May 17, 2010. Mechanical, Controlled By 700R4 Type Cable. When I removed the 2-3 modulator valve components out, the 2-3 valve spring came out in many pieces (this is what ron sessions book calls it, referring to #20 on page 125). Learn how the Th400 vacuum modulator diagram can help you understand the inner workings of your transmission and troubleshoot any issues. did you check the vacuum modulator vacuum tube. The gearbox doesn’t shift down on a hill climb either. Check it out!For more content visit:instagram. This mod is for full line pressure control in all gear ranges. There is no linkage from the carb to the tranny, it is vacuum operated. Pre-bent to factory specifications, the lines feature the correctly bubbled ends, which keep the rubber lines in place at the modulator and the How to adjust the shift modulator valve to raise or lower the shift points in your transmission. 1 is the governor which monitors tailshaft RPM, #2 is Vac modulator. Item model number. com: Vacuum Modulator Retainer Clip Hold-Down Bracket With Bolt, fits GM TH400 Heavy Duty 8627650K : Automotive Check These Out. #17 · Oct 24, 2012. watch this video in its The TH400 uses both. Adjustable Vacuum Modulator Suit TH350 & TH400. For TH350 and TH400. Call a local transmission shop. 350001TCI. This is done by turning the adjustment screw inside of the vacuum line connection for more or less diaphragm preload, thus raising or lowering part throttle shift points and line pressures. I manually shift the car at right around 6000 Coloradoracer. #1 · Apr 11, 2010. Get yours online today and pick up in The TH400 uses an electronic kick-down mechanism, which means that there will be an electric plug on it. "As betting at the race ring adds neither strength nor speed to the horse, so the exchange of shares in the stock market adds no capital to business, no increase in the production and no Product Details. I dunno if this pertains to you, 2007-2020 CHRYSLER DODGE RAM TRANSMISSION SOLENOID MODULE MOPAR 68376696AA. TH400 Family Production Run: 1964-1991 Variants: THM375 (1972-1976) - Lighter duty; 27 spline output shafts; THM400 (1964-1994) Delete the vacuum modulator (which needs additional modifications to vent reverse boost oil) then grind the largest land off the modulator valve, or braze shut the “gov to mod” hole in the plate*. In this video I service the GM Turbo 400 on my 1976 Holden HX Monaro LE Coupe. As a part of the transgo reprogramming kit, you can remove that spring to firm up shifts. $31. Explore a detailed How To Adjust TH350 and TH400 Shift Points with a Vacuum Modulator. C. watch this video in its Info. This section does not cite any sources. #3 · Dec 16, 2001. | Search this page. Be sure to use an adjustable modulator. I just decided to address it. We have the best Automatic Transmission Vacuum Modulator for the right price. 28 $ 36. Vacuum Modulator Retainer Clip Hold-Down Bracket With Bolt, fits GM TH400 Heavy Duty 8627650K. 170 posts · Joined 2010. Fits 1970–1972 Buick Skylark, 1970–1972 Pontiac GTO, 1970–1972 Pontiac LeMans, 1970 Pontiac Tempest, , , , . for the down shift, th400's use an electric switch with a 12V input to the trans. This will have main line pressure raised. Simply TCI 350001 GM TH350/TH400 Adjustable Vacuum Modulator Valve. Coloradoracer. It is a simple replacement. Part throttle shifts are controlled by the vac modulator and the governor. The total adjusting range of these modulators is about 4 to 5 MPH at WOT. You can find all the fittings/line in the Zip catalog :thumbs: The vacuum modulator valve on my TH400 was painted all white and has following information stamped on it: HRD G4 581 Google did not learn me anything? Thank you, Jake . if it is not hooked up it will shift somewhat inconsistently. If you have a carb, the port will usually be in the baseplate but check to be sure, especially if you have a Q-jet. Does there exist a conversion that will convert a TH400 from vacuum modulator to a TV cable operation. On a stock TBI, the correct port should be on the back side between the fuel lines (see below). The transmission has a input shaft that is 7. 24 44 13. Joined Jun 5, 2003 Messages 28,308 Location Apple Valley, California . Shop All TCI Automotive. I show and discuss that just changing the Modulator may not help anything. The next step is to find the vacuum modulator. What does the vacuum modulator on a Turbo 350 do? The transmission vacuum modulator is located on the side of the transmission, near the front. Locate the converter Of course it will be 0. B&M 20234 Part Number: 130-20234. Rostra 51-1210-36-00 Ford Cruise-O-Matic Vacuum Modulator Blue Stripe Single Diaphragm FMX FM FX MX. 48. 2's with Th400's the Vac Modulator line is connected to the vacuum pump. 05. Turbo 400 Performance Racing Transmission Parts by FTI Performance. 2L diesel switch-overs. drdave69 Discussion starter 62 posts · Joined 2002 Add to quote; Only show this user #1 · Apr 5, 2022. It is supposed to have a My TH400 started spewing fluid recently from the Vacuum Modulator area. What is the best way to adjust shift points on one of these units? Thanks. ooooo. B&M's vacuum modulator is fully adjustable and allows you to tailor your shift points to within a range of 2-4 mph. Getriebe Modulator Vacuum Chevy TH350 TH400. Th350 has the vacuum modulator in Remove the vacuum hose from the modulator, there will be a screw inside of the assembly. Do not modify the PR valve or block the indicated hole when the PR valve is modified. Rating Required. Shop for TCI Auto GM TH350/TH400 adjustable vacuum modulator with confidence at AutoZone. FTI Offers a wide variety of TH400 Parts including racing transmisison pumps, valve bodies, gear sets and deep transmission pans. « Reply #1 on: March 03, 2013, 10:20:47 AM ». Vehicle Fitment Guide. My kickdown doesn't work and I 683 posts · Joined 2002. It is a small, black, cylindrical device with two hoses attached to it. Adjustable Vacuum Modulator. 26 TH400 FRONT 350 350C TH350 400 TH400 ST300 JETAWAY TRANSMISSIONS: ADJUSTABLE VACUUM MODULATOR, NEW, SINGLE RED STRIPE. $53. #1 · Nov 25, 2016. I'm trying to install my vacuum modulator line for a turbo 400 and 396/325. Thanks I seem to TH400 Family Production Run: 1964-1991 Variants: THM375 (1972-1976) - Lighter duty; 27 spline output shafts; THM400 (1964-1994) Delete the vacuum modulator (which needs additional modifications to vent reverse boost oil) then grind the largest land off the modulator valve, or braze shut the “gov to mod” hole in the plate*. 65. Louis should have plenty 17538 posts · Joined 2010. 53. However, it is the TH400 if this fitting is at the transmission’s Super Turbine 400 / TH400 / THM400 / THM375 / 3L80 / 3L80HD. At WOT the vacuum will be near zero and the modulator will be ineffective. Save Share. Over time, modulators can develop leaks, suffer ruptured diaphragms, become bent These "vacuum modulator-assisted" transmissions will employ a kickdown cable (or an electric switch, in the TH400's case) that serves only to "kick-down" the trans into a lower gear for passing TH350 TH400 Cable Operated Modulator 350 400 | eBay The fourth is to locate a vacuum regulator valve used on one of the Oldsmobile diesels. If you have a vacuum gauge, check what the modulator is seeing. #10 · Feb 19, 2011. Also, mine shifts harder with A/Trans Vacuum Modulator (Adjustable) Vacuum Modulator Valve Color Code: White Stripe: VMRS Code: 027-026-002 # Vacuum Modulator Valve Hose Connectors: 1: Buyer's Guide. com. 69 SS396 Camaro, 4link, 12bolt posi, Speedtech LCA / UCA's, Hotchkis 2" drop front springs/sway bar, TH400 MODULATOR-SOLENOID O-RING (TH400, TH350) Related Items. $61. B&M makes a cable modu-link for the th-400. This vacuum line fits between the transmission vacuum modulator and the intake manifold fitting. that the valve in the transmission case may be the issue. The modulator adjusts the transmission’s shift timing as these changes occur, according to the engine’s demand. #2 · Sep 23, 2004. 'carnuck' is right, I read about this problem in GFSJ. Th400 relies on 2 things to detemine shift points. " Adjustable Vacuum Modulator – This replacement vacuum modulator for the TH400 has the added feature of being adjustable. 710 posts · Joined 2011. (79 C20) I took the truck for a test drive and everything went fine. $101. Pre-bent to factory specifications, the lines feature the correctly bubbled ends, which keep the rubber lines in place at the modulator and the It occurred to me that many Diesel engines used the Th400, and the diesel engines don't really make much in the way of vacuum. Rating Many early transmissions, such as the TH400, used a vacuum modulator mounted to the transmission case. 23. Problem being very low manifold vacuum at idle ~10" which results in the modulator being inactive -allowing highest possible pressure at idle => hard jerk when Registered: 2012-04-01. Over time, modulators can develop leaks, suffer ruptured diaphragms, become bent, etc. Application: TH350 1969-1986. 11 x 16. (Applies only to TH-350 and TH-400 with automatic valve bodies. Produkt jetzt als Erster bewerten nicht auf Lager, Bestellung bei Anfrage möglich Bei Verfügbarkeit benachrichtigen. You can but a tuning kit for it. Adjustable for early or late shift. Have no fear, it can be done. MwSt. Is your transmission shifting too early or too quick? Then All good advice, to the OP are you sure you are hooked up to manifold vacuum for the modulator? If the governor is working a stock Th400 will upshift from 1st at full throttle no matter what forward gear the shifter is in, but it will be high RPM. L. 7. For GM TH350 and TH400 automatic transmissions. #3 · Jul 2, 2010. Hoping to get my hands on one this week. sort by: 125 125c 200 200c 2004r th350 th400 700r4 4l60e 4l65e 4l70e 4l80e 4l85e 4t60 4t60e 4t65e cd4e transmission filler tube boot fits '69+ (1259475) 350 350c th350 400 th400 transmission adjustable vacuum modulator black/ red stripe fits '69-'87 & all diesel. There is no mechanical I show and discuss that just changing the Modulator may not help anything. This line goes from the carburetor to the transmission modulator. Vacuum Modulator, fits GM TH350 Adjustable, Single Red Stripe & Retainer Bracket Clip K35820RB. If fluid comes out, the modulator is no good. When the solenoid is activated (12 volts), the line pressure also increases slightly resulting in a slightly higher rpm shift point. GM part # is 23500822 at $108. Th400 has a broad-looking face compared to Th350. The vacuum hose to the modulator was replaced, and I had to "turn in" the screw inside the modulator to lengthen the period of time in between shifts. T-400 modulator line. 1. Shop Now at the Delete the vacuum modulator (which needs additional modifications to vent reverse boost oil) then grind the largest land off the modulator valve, or braze shut the B&M adjustable vacuum modulators let you adjust your shift points within a range of 2 to 4 mph. My car is equipped with power disc brakes, cowl induction, and A/T so it Buy Vacuum Modulator Retainer Clip Hold-Down Bracket With Bolt, fits GM TH400 Heavy Duty 8627650K: Transmissions & Parts - Amazon. 05 $ 21. Part Number: 890-350001. FREE delivery Thu, Jun 13 . The TH400 is an early model, non-computer-operated transmission widely sought after by car enthusiasts for its internal strength. When the engine is under load and vac is low, the line pressure in the trans will go up. Part Type: Automatic Transmission Modulators. That's it. This increases the holding power of the clutch packs, increases oil flow to the torque converter, and delays the shift. 73 rear end. TH400s used a switch on the throttle linkage instead of a kickdown cable for this function. Location Cloverdale IN. My TH400 has the small modulator already installed. SKU # 862566. Is your transmission shifting too early or too quick? Then 70ChevelleRagtop. from Big Sky Country Montana. Everything runs/shifts great. Adjustable vacuum modulator for General Motors TH350, TH350C, and TH400 transmissions, 1964-On. T5 5 spd. Replaced the vacuum modulator and got 3rd gear back. you should Where to find TH400 Vacuum Modulator O-ring?! Usually I'm pretty good at find this stuff, but seems like everyone lists the modulator assembly (which mine is fine), but not just a replacement o-ring. The valve fits into the transmission housing and controls vacuum used for shifting and kick-down functions. Th-400 Modifications. 963 posts · Joined 2003. 2 and 5. No or low vac to the modulator tells the trans that you are under power, and want the fastest, hardest-hitting shifts possible, at a higher speed. Attach it to the intake with a small piece of rubber hose, and the trans end you use another piece of hose. Product Reviews. If the O ring is bad, it is probably a 50 cent fix. Product Q&A View Now. TH350 TH400 VACUUM MODULATOR Red Stripe Transmission & Extras. Automatic Transmission Master Repair Kit, Ford, Lincoln, 4R100, Kit. Thanks I seem to 355 posts · Joined 1999. The problem is that if it had a check valve in it, the modulator will still see vacuum when under part throttle or full boost. 18 posts · Joined 1999. Comes supplied pre-adjusted for normal shift points. Mark Goulette. When I was taking apart the transmission for my 76, the spring behind the With a moderate cam, vacuum is lower, and a higher stall converter will have less effect on engine vacuum at lower throttle openings, so the modulator adjustment will have less or no effect on minimum or part throttle shift points, but some effect on harshness. Brand: B&M. Drucken. Governor problem. B&M adjustable vacuum modulators let you adjust your shift points within a range of 2 to 4 mph. On some models there is a wall in the passage at the location shown in Figure 5. Check vacuum advance connected, clear and operable. TCI 350001 GM TH350/TH400 Adjustable Vacuum Modulator Valve. Two questions: First is around torque converters and a recommendation for that: Having a TH400 built to go behind what will be a newly built SBC 383. Simply adjust the screw inside of the vacuum nipple for more or less diaphragm preload. 2007 JK Rubicon. 229 posts · Joined 2006. 350 350C TH350 400 TH400 TRANSMISSION ADJUSTABLE VACUUM MODULATOR BLACK/ RED STRIPE FITS '69-'87 & ALL DIESEL. #1 · Sep 20, 2009. History; Careers; Own a NAPA Store; Affiliate Program; Suppliers; Professional Services; 21010 posts · Joined 2009. #4 · Feb 10, 2011. Rostra 51-0308-02-00 GM Aluminum Powerglide Adjustable Vacuum Modulator Rostra 51-0062-02-00 GM Adjustable Vacuum Modulator Dual Red Stripe TH350 TH350C TH250C TH400 TH425. The modulator references engine manifold vacuum and provides the appropriate signal to the transmission as it relates to engine throttle position and engine load. 856-400-0063 (call only, text function not working) Sign in or Register; ADJUSTABLE VACUUM MODULATOR, NEW, SINGLE RED STRIPE. 53 $ 61. See Figure 2-13. Allows you to Tailor Shift Points. I recently changed the transmission in my truck. Note that modified transmissions may not use a modulator assembly. Rostra 51 Vacuum Modulator Line, TH400, 1970-72 Skylark/Pontiac A-Body, 1/4". 2525 posts · Joined 2003. Jumpstart Your Next Project! Find Parts and Accessories th400 vacuum modulator KEYWORD and get Free Shipping on Orders Over $109 at Summit Racing! These transmission modulators are available for several applications and allow you to fine-tune your shift points and shift feel. If the transmission's vacuum modulator begins to fail, the hose that attaches the engine vacuum to the transmission can burn out and cause engine damage. No vacuum to modulator. B&M 20234 B&M Adjustable Vacuum Modulator GM TH350 & When you get ready to run the vacuum line from the turbo 400 trans modulator to an Edlebrock Performer 800 CFM carb, attach the vacuum line for the transmission vacuum modulator to the bottom 1967-69 Camaro, 1968 Nova V8 TH400 Stainless Steel Transmission Vacuum Line This transmission vacuum line is reproduced in the correct configuration for an original appearance and fit. The purge Vacuum Modulator Lines, TH400 Transmission, 1967 Bonn/Cat/GP V8 4BBL. If there is voltage at the trans connector, a wire in the trans came loose or the kick down solenoid in the trans is fried. FREE Returns. Red Stripe Vacuum Modulators have an adjustment screw right inside the stub where the hose goes on. #1 · Apr 29, 2004. 6 out of 5 stars 7. Red Forman: "The Mustang's front end is problematic; get yourself a Firebird. Don't put 12 volts on the black wire. Vacuum Modulator Adjust and Test#cars #automotive #transmission #gearbox #automatict Instead of just the modulator, there is also a 60 deg. My 1986 M1008 has been shifting hard so i tried to replace the vacuum modulator. I know from reading it needs full manifold vacuum to TH400 brackets for mechanical modulator. FREE delivery Mon, Nov 20 . B&M's vacuum modulator is fully adjustable, this allows you to tailor your shift points to within a range of 2-4 mph. Note: If you have a big camshaft and TH400 Won't shift into 3rd!!!! Hey guys I am experiencing some issues with my th400. The electrical signal activates the detent regulator circuit which enables kickdown into a lower gear at WOT. Overall dimensions . 0 out of 5 stars 1. Reverse and Transbrake should be performed on all TH400 transmissions with increased or fixed line pressure to reduce converter charge pressure to a safe level. Push in type, single red stripe. Thank you so much for watching, If you enjoyed this video please like, comment, and subscribe. The current unit in my '68 has developed a leak in the The B&M® vacuum modulator is fully adjustable and allows you to fine-tune your shift points and shift feel. throttle position curve that a gasoline engine would have. Hey guys I am experiencing some issues with my th400. Being electrically controlled by the driver, it provides lightning-fast launches at the dragstrip. FREE delivery Wed, Oct 18 . See Figure 2-12. Model. 7 have 3 things in common, you put oil in the pan, antifreeze in the block and it burns diesel TH400 Electric Kickdown functionality. 5 Detro vacuum modulator and vacuum modulator valve. The vacuum modulator works similarly, but does its work at partial to mid range throttle based on The Right Stuff CTV6903 Transmission Vacuum Line (Turbo 350, Right Hand Modulator) Visit the The Right Stuff Store. 75 out of 5 stars. FREE delivery Wed, Jun 12 . Shop Summit Racing now! Automatic Transmission Modulator Line, Steel, Chevy, TH400, Each. Vacuum source hooks up to nipple closest to engine, nipple to modulator is on top (closest to Getriebe Modulator Vacuum Chevy TH350 TH400. It mounts to the outside of the TH400, replacing the vacuum modulator. pull it off at the back of the intake. Jump to Latest Follow 13K views 20 replies 10 participants last post by drdave69 Apr 13, 2022. $2599. B&M Vacuum Modulators. Home delivery unavailable. Or fastest delivery Wed, Nov 15 . I can't seem to figure out why my th400 is shift so late. Feb 13, 2014 #9 I know that trans shops will stuff one into park at speed hoping to free up a stuck governor. Another thing guys will do is use an electronic vac modulator eliminator. I have a blown bbc and I have my th350 hooked up to manifold, at the time without much thought other than during normal driving I will have vacuum below the blower and the modulator will function fine and when I get Brand: Rostra Precision ControlsOther Part Number: 35820RType: Rebuild KitManufacturer Warranty: YesCustom Bundle: NoFitment Type: Direct ReplacementItems Included: ModulatorManufacturer Part Number: 51-0017-00-00Bundle Listing: YesTransmission Type: Automatic Turbo 350 TH350C TH375 TH400 3L80 Vacuum Modulator "Dual Re TCI Automotive. At cruising speeds you will get about 2 MPH total adjustment range. Review Subject Joined Jul 18, 2011. The vacuum modulator is used to eastablish the load on the engine. I read and respond to ALL comments, so why not leave one :)foll BM20234 - B&M VACUUM MODULATOR FITS GM TURBO 350 & 400 TRANSMISSION. My car shifts great. These vacuum lines are an authentic reproduction of original equipment and are a necessity for proper transmission operation. This mechanical modulator is designed to take the place of the vacuum modulator on all 700-R4 to 400 6. 4. The modulator is connected to the engine by using steel tubing and rubber hosing. Anyone have any idea where I can find a new original style modulator? 721 posts · Joined 2007. It needs to be bent at a 90 degree angle, so The heart of the transbrake is the solenoid. This is to make clearance to the front drive shaft. Vacuum Modulator Lines, TH400 Transmission, 1967 Bonn/Cat/GP V8 4BBL. #3 · Sep 4, 2005. But the $900. which mine had a plug. There should be two lines at the purge valve. Pull the rubber line off the modulator and see if transmission fluid comes out of the line. #3 · Feb 8, 2013. Steel line with the correct bends. Colorado Jeep Club member 304 . I also recently readjusted my vacuum advance. 107 posts · Joined 2009. I found NOS modulators and that is not a problem. Warn Powerplant HD . Vacuum modulator? I recently had to put a new shifter cable on my Hurst ratchet shifter on a th400. Includes $3. 5 inches in At the time the modulator was about $3. 8 @ 115mph. Select store for pickup availability. Or fastest delivery Thu, Oct 12 . Helping a friend out and looking for the "proper" way to hook up the modulator. December 23, 2014, 05:52:13 PM. TCI® comes to the rescue with this line of adjustable modulators. After install no difference. 19 $ 101. Straight manifold vacuum IS too much. The vacuum line for the truck is still the steel one but 400 th400 th375 th425 th475 3l80 transmission parts & rebuild kits. One bolt to release the clamp, remove vacuum hose and slide out old one and slide in new one. My car is equipped with power disc brakes, cowl induction, and A/T so it Transmissions that use a vacuum modulator include the GM Powerglide, TH350, and TH400; and the Ford C4 and C6. Mark Vilbert in St. Currently unavailable. Modifying the modulator raises the pressures inside the transmission and makes life How to Test a TH400 Vacuum Modulator. . I've made sure the vacuum modulator is getting full manifold vacuum and I've adjusted the modulator numerous times to the point where I just took from Metro Hiram. Or Email us using our CONTACT link above. I have a turbo 400 for 69 chevelle and big cam/low vacuum engine. If I rev the motor up a little it will jump back into drive. Includes vacuum tube and very important oring. TH400 1965-1998 GM TH350, TH400, and TH700R4 / 4L60 (not including 4L60E / electronic shift models) B&M part numbers: 102002 - 103005 - 107101 - 107104. This probably isn't enough to suit. Is discontinued by manufacturer. 18. You can start and drive the engine without the down shift connected (for now). If you are experiences problems with shift points, this could be I explain what the vacuum modulator is and its primary function and go for a test drive There are more transmission videos in my playlist if you want to see more #modulatoradjusting #turbo350 Read on to discover the step-by-step process for adjusting the vacuum modulator and unlocking the full potential of your Turbo 400 transmission. TH400 is the 800 pound gorilla of automatic transmissions, this means plenty of heavy metal spinning in clutch packs/gear sets. Renew performance, and gain the ability to slightly raise/lower part throttle shift points and line pressures. I change the oil filter, the Vacuum modulator, internal kickdown solenoid and The vacuum modulator affects mostly th e light throttle shift points. This unit comes pre-adjusted for normal shift Remove the modulator retainer bolt (11) and modulator retainer (12) from the transmission case. 350 350C TH350 400 TH400 TRANSMISSION ADJUSTABLE VACUUM MODULATOR DUAL RED STRIPE HI-PERFORMANCE. My new line does not have a bracket attached. Mind you this transmission would shift VERY early prior to rebuild and in D would hit 3rd before crossing an intersection. Artikel-Nr. 14K views 8 replies 3 participants last post by Unstable Apr 12, 2010. The tranny shifts itself into 1st, 2nd, and will only shift itself into 3rd (Drive) when i really get on the throttle, and shifts into 3rd (Drive) around 3500-4000 RPMs. 70 Chev suburban 4x4,60/14bolt ff,divorced 205,pto lu-4 winch,3. Fits 67, 68 & 69 Chevelle models. M. B&M Vacuum Modulators 20234 BMM-20234. My only advice is to get an adjustable one. Car is between 3100 - 3200 pounds and street driven only, no track TCI Auto GM TH350/TH400 adjustable vacuum modulator. 7640. $40. In the process of running new cooler lines today, the steel vacuum line going to the modulator fell apart. Not sure if part of the problem is that I only have 17" of vacuum. Full throttle shifts are controlled solely by the governor. When there is more vacuum from the engine, the transmission will have an easier shift feel to it. TH400 modulators are a type of valve that is designed to assist in controlling shift patterns. Starting with the 1979 model year, vehicles which had the THM-200/200C as standard equipment were optioned with the THM250-C, which is New 427/390 dyno'd at C3 Tech/Performance - TH400 Modulator Vacuum Line - Wow. TH400 vacuum modulator? Jump to Latest Follow 2K views 8 replies 5 participants last post by Jims56 Jul 30, 2014. $36. com FREE DELIVERY possible on eligible purchases Amazon. 4007 posts · Joined 2000. Estimated Ship Date: Jul 16, 2024 if ordered today. Price: $ 90. The vacuum modulator is a vital component of automatic transmissions. When I am at WOT making a pass it will not shift into third gear. #1 · May 27, 2008. I bought a B &M adjustable modulator. Always FAST USA SHIPPING! For questions or to place an order by phone, please call our solutions desk at (888) 324-1617 8AM-6PM PST (West Coast USA). I am having trouble getting my tranny to kickdown properly. With a gold cadmium finish and an O-ring seal to stop leaks, they will look as good You can make minor changes to the shift speeds by installing an adjustable aftermarket vacuum modulator. A th400 has an internal electric kick down solenoid. Check adjustment of shifter cable detents. I also noticed the old vacuum modulator was Re: Transmission modulator line on TH400 (73'Vette) 73, The modulater line goes up from the modulator, passenger side, then attaches to the top vacuum port on the manifold just behind the carburetor with a very short vacuum hose ta a "Y" fitting made to attach two vacuum lines. Original price $34. You can go two turns in or out. B&M used to make a cable actuated modulator assembly for TH400's that didn't have a good vacuum source. Manual valve body units do not . $3599. #6 · Sep 7, 2010. B&M Adjustable Vacuum Modulator GM TH350 & TH400. 27,95 € Preis inkl. ABOUT NAPA. I have a picture in my album. Jims56 Discussion starter 2288 posts · Joined 2007 Add to quote; Only show this user #1 · Jul 29, 2014. 49. #1 · Dec 26, 2004. The TH350 transmission is a four speed automatic transmission that is found in most GM vehicles. cucvrus said: A quick test. "Th400 relies on 2 things to detemine shift points. The ultimate oopsie in forgetting to install the steel modulator vacuum line before dropping the bodyand installing too many items to retro-fit that line in the proper place. I recall most trans vacuum lines coming off a vacuum port in the back of the intake, not off the carb. Push in type, black & red stripe, adjustable. loafing1 Discussion starter. Use a magnet to remove the vacuum modulator valve (15) from I did a search and found that to make my TH400 shift later I need to tighten the flathead screw in the vacuum modulator clockwise. Check line pressures: Road, variable speed 60psi min to 150 forward gears, steady state 150 and 95-260 in reverse. The modulator has to be hooked to a full time vacuum source (called manifold vacuum). #1 · Jan 8, 2010. Vehicle Specific View fitment for 3 models. Or simply start grinding on the inner weights for later WOT shift gearheadmb. adapter it mounts to on the transmission. Under power my Th400 is shifting way too early. ATP Automatic Transmission Master Repair Kits FM-40. These old transmissions are easy to work on so dive in, you will be glad you did it yourself. Pre-bent to factory specifications, the lines feature the correctly bubbled ends, which keep the rubber lines in place at the modulator and the 1672 posts · Joined 2009. NO, the modulator has nothing to do with the "kick down" function of the transmission. I'd like to replace it with the original style modulator, but all I can find are the newer style ones (smaller, gold color with red band). Add to cart-Remove. 95 TH400 FRONT PUMP O-RING (0) Your Price: $3. ) 6. Menu. Unless it is a race-only deal, I would not do it unless you call ahead to your dentist to replace any fillings that rattle out. $21. the other goes out to the canister. com The vacuum modulator position TH400 transmission turbo controls the amount of vacuum applied to the transmission gears. The fitting is a 90-degree "street elbow" type (has a male end and a female end), that most importantly has a tiny internal orifice to limit the vacuum to the modulator. I HAVE SEEN SEVERAL SITES WHICH HAVE DESCRIBED THE DUAL FEED MODIFICATION, TAKING SPRING OUT OF 2-3 ACCUMULATOR, DRILLING THE FEEDS IN (1-2) (2-3) FEEDS IN VALVE BODY, AND GRINDING THE FLATS ON THE (1-2) VALVE. Black Red Stripe VACUUM MODULATOR TH350 TH400 Transmission. Homebuilt TH400 with Jake's Performance Stage II kit and the usual mods, 3500 Edge converter 3950# race weight, 3. You will need to leave the modulator unless you have replace the valve body with a manual unit. Part Number: CST-CAM1002-OE. without the kickdown hooked up it is totally reliant on tailshaft speed and the modulater signal to shift. I bought a replacement for the TH400 at Standard Auto Parts and tried to install it however the shaft that is to be inserted into the transmission was just slightly too wide and would not fit. Qty: + Buy Now. IIRC, there is a specific port for the (vac modulator on a TH400). 856-400-0063 (call only, text function not working) Sign in or Register; Cart. This can be caused by bad vacuum line, crud built up in fitting at motor, Bugs built nest in line after it was disconnected for awhile 2. 350 350C TH350 400 TH400 ST300 JETAWAY TRANSMISSIONS: ADJUSTABLE VACUUM MODULATOR, NEW, SINGLE RED STRIPE. 00 Amazon I have had a hard second gear shift on my TH400 since I got the car 5 years ago. Comes preadjusted for normal shift points. I bought one today from the local parts store and tested with the following results: Fully adjusted (adjustment screw removed) modulator plunger begins to activate at 6hg Vacuum and appears fully retracted by It has a vacuum modulator that detects changes in the engine’s vacuum as a result of throttle position and load changes. Your transmission relies on the vacuum modulator to function properly, and you can rely on TCI and their adjustable vacuum I do believe on the 6. 4 out of 5 stars 9. This is done by turning the adjustment screw inside of the vacuum line connection for more or less A new vacuum modulator for TH350 and TH400 Transmissions, 1965 & up. I hope this trans is I do believe on the 6. I have a 1970 Monte Carlo SS and realize it is similar to Chevelle. This works well for superchargers and on diesel motors without a vacuum regulator. #1 · Jun 16, 2010. Add to Cart. 50 $ 35. Please Call Us To Confirm Instore Availability. As vacuum drops with high load, this changes the position of the vacuummodulator valve in the transmission and increases the line pressure and also delays the shift point. As already indicated, the th400 trans uses an electric switch for the kickdown or downshift during hard acceleration. This product is not available, please call customer service for options, at 1-800-345-4545. Hi All, Would like some info from anyone who has expereince changing the vacuum modulator on a TH400. 2 and Th400. Discussion starter · #1 · Feb 16, 2012. Illustrative Only. GM, TH350/TH400 Adjustable Vacuum Modulator . TH350 has its vacuum modulator located at the front of the rear position of the gearbox. Thanks. Safety Information. Part# CTV7005 I did some googling and found your average mid-eighties Chevy Diesel 6. As the original style modulator would hit the drive shaft if installed normally. anthony Discussion starter. I'd like my tranny to hold 1st gear a bit longer. I adjusted it out two turns and it was a little better. 1975 Nova w/1966 427/manual th400, 11. You don't see the 2 wires on your diagram because the Turbo 400 is an optional trans. "As betting at the race ring adds neither strength nor speed to the horse, so the exchange of shares in the stock market adds no capital to business, no increase in the production and no • vacuum hoses • transmission cooler lines • gear selector linkage • throttle (or kickdown) wiring, cables or linkage • speedometer cable and any other similar items. POWERGLIDE EXTENSION HOUSING SEAL (PG, TH350, C4, 700R4) Your Price: $10. I am not sure which port it should connect to on the intake. Remove the vacuum modulator assembly (13) from the transmission case. Modulator Black Red Stripe TH350 TH400 TH350C TH250 TH250C 3L80 M38 MV4 MX2 M31 M40. 1968 TH400. Does the TH400's vacuum modulator require 20+ of vacuum, or am I okay with 17? Share. B&M Adjustable Modulator - GM TH350/TH400 Automatic Transmissions. $8 delivery Oct 17 - 20 . Search on here for converter recommendations, we've covered most of the usual suspects and for a TH400, they'll be a little cheaper than say a 4L60e . Fairfax Station, VA 22039 (Washington DC Sub) 1970 Cadillac DeVille Convertible. Description. TCI. Is this a micro-adustment or The modulator affects shift firmness, and the shift timing as a "side effect". 856-400-0063 (call only, text function not working) 350 350C TH350 400 TH400 TRANSMISSION ADJUSTABLE VACUUM MODULATOR BLACK/ RED STRIPE FITS '69-'87 & ALL DIESEL. OLDED - It's STOCK if it's made by GM and it fits! *65 Elky, Gen VI 496 BBC, TH400. Also have a LOKAR baltimore/maryland. Problem being very low manifold vacuum at idle ~10" which results in the modulator being inactive -allowing highest possible pressure at idle => hard jerk when No vacuum leaks that I can find although the engine vacuum is a little low relative to what I had on the dyno (7 vs 11). The governor calibration will therefore be the best way to adjust shift points. Find many great new & used options and get the best deals for B&m 20234 Transmission Vacuum Modulator for GM Th350 and Th400 at the best online prices at eBay! Free shipping for many products! TH400 Adjustable Vacuum Modulator Kit. SHARE POST #2. Allows you to tailor shift 1Fast7D. Remove the vacuum hose from the The heart of the transbrake is the solenoid. com/burno 7. 14. Product Dimensions. These vacuum lines are an authentic reproduction of original equipment and are necessity for proper transmission operation. It's a switch to ground. IIRC, there is a specific port for the 447 posts · Joined 2008. 54 TH350 (Late) Teflon Sealing Rings (0) Your Price: $9. Add To Cart. This vacuum modulator valve is a must-have for all TH350 and TH400 automatic transmissions. 1970 Cadillac Sedan DeVille. Remove the starter. However, as I stated above, the modulator valve (in the case) might be sticking when fully inserted 461 posts · Joined 2007. I know another company makes them now too, just can't remember who it is. I have adjusted the vacuum modulator all the way in (no change), replaced the vacuum modulator with a known good one (no change). Today 50% of all marriages end in divorce, but 100% of car part deliveries end in happiness. if you apply, release and apply vacuum again. USA Parts shows that for 1971 (from 64 thru 72 it is all the same), the vacuum modulator they sell fits both FWD and RWD. A WEBSITE crankshaftcoalition. Vacuum Modulator Line, TH400 Transmission, 1969-70 Bonneville/Catalina, 4BBL. Although not strictly necessary 68502. Currently, if I sit at a light for more than 20 seconds the truck shifts into neutral. Hard line from manifold to modulator with a short rubber line at each end. D. You’ll know it’s the TH350 if you have the fitting attached to the right frontal side of the transmission. 5 x 17 BFG KM2s, 5. 96 TURBO 400 TH400 TH350 TH250 RED STRIPE ADJUSTABLE MODULATOR 1965 UP for GM. Get the Best Performance with JEGS Transmission Vacuum Modulator for GM 1963-1990 TH350/TH400 [Adjustable] 62068 parts at JEGS. One coming from the engine that is vacuum allthe time. Pontiac 400 and th400 vacuum question. $35. Connect the vacuum modulator and manifold vacuum . As soon as a gear change is executed in line with the load demand, the diaphragm pushes the valve to prompt the spring to move in the reverse direction of the diaphragm. At wide open throttle it shift fine but at part throttle the 1-2 shift happens at around 45mph and the 2-3 shift happen at around 60mph. It controls a special modulator valve supplied with the TCI kit. It tells the transmission what kind of load is being put on it, allowing the transmission to react with the proper line pressures and shift points. Low-vacuum situations, which require heavy-throttle or full-throttle application The transmission vacuum modulator effectively works by consistently computing the load in your car’s engine with the diaphragm. 95. Yours was probably never set. First I have well over 200 passes on the transmission and it came with the car when i bought it, so I knew it was going to happen sooner or later. Add TO CART. 5 inches in M. 4 20 ratings. TH350 / TH400 Cable Operated Modulator. Trans Temperature Gauge Kit – Most transmission and converter failures can be traced directly to 355 posts · Joined 1999. Torana68, Apr 14, 2011. All that weight is stupid strong, but you pay a price in weight bearing down on supports, the very Quick video to show you how to adjust shift points on your Chevy/GM vehicles equipped with the 6. 96 $ 53. I checked fluid level, vacuum at modulator is 15 and engine is tuned but problem exists. May be similar for 6. A couple of questions: 1) what is the purpose of the vacuum modulator of the TH400 Transmission? (I was thinking either it is the controller for downshifting or the controller for normal shifting?) 2) I bought a repro modulator-to-intake steel line. , 4:11 posi. Just connect a manifold vacuum line to the modulator on the trans. 73 Detroit locker rear, power loc front, 35s on 16 X10 weld wheels, 2400 Allison 5speed,triple disc billet How to adjust the shift modulator valve to raise or lower the shift points in your transmission. 6 out of 5 stars On a TH400 the vacuum modulator controls the line pressure inthe trans according to engine load. With a gold cadmium finish and an O-ring seal to stop leaks, they TH400 Modulator. I installed the 400-3 TransGo kit in my Turbo 400 and I also have less vacuum than you. Less vacuum actually holds the gear longer. Vacuum line going to the th350 modulator. rostra Vacuum Modulator Line, TH400 Transmission, 1970-72 Grand Prix 4BBL. Name Email Required. TH350 / TH400 Cable Operated Vacuum Regulator Valve - seems to test fine, it is presently set to delivery 18" vacuum to the modulator at engine idle, and vacuum drops off consistent with increased throttle movement to a point of zero vacuum. Anyone have any idea where I can find a new original style modulator? Product Description. CT3473 - A vacuum modulator retainer for the TH400 Transmission, 1965 & up. They should have them on the shelf. The vac modulator is what tells the trans what kind of strain is being put on the engine and when and for how long to wind out the shift points. Equipped with a gold irradiated finish and an O-ring seal to stop leaks. The vacuum modulator definitely affects shift timing. The modulator needs to have 0 or near 0 vacuum when under load to raise pressure high enough to keep it from slipping and burning up. Fully adjustable. Details. Jumpstart Your Next Project! Find Parts and Accessories th400 vacuum modulator KEYWORD and get Free Shipping on Orders Over $109 at Summit Racing! Modulator valve leaks are very common on the TH400. 18 - Original price $34. Jul 21, 2020 #11 muttly Member. Chevrolet C20 1967 TH400 Slipping through 2nd Gear and fast 1-3 Upshift. Recommended. Fine Lines Vacuum Modulator Line, TH400, 1970-72 Chevelle/ El Camino/ Monte Carlo. These "vacuum modulator-assisted" transmissions will employ a kickdown cable (or an 5. Ed. With that kit, you simply leave the governor mods out, and it will still shift automatically. 5 Rock Krawler X-factor lift w/37 x 12. 0 out of 5 stars. TCI Automotive 862566. : ATP-JX67. 390 Posts. That's what is in all the CUCV Military trucks is the 6. 595 My last engine only made 12" - 13" on a good day and the TH400 responded well to that connected to the carb - use an adjustable Vac. Th400 has it placed at the right side of the same position. Add to Wish List Add to Compare. From the Vacuum modulator, the transmission’s weight, bolt patterns, and length, there are visible differences between Th350 and Th400. 2 or there abouts, had a Th400 and vacuum modulator. If you disconnect the vacuum to the TCI Adjustable Vacuum Modulator GM TH350/TH400. Modulator and crank it down. Parts are just part of what we do. 50. A) Does anyone sell the modulator lever? B) It looks like I can just remove the elbow and install the modulator directly onto the trans (like GM Install: B&M Vacuum Modulator for GM TH350 & TH400 Automatic Transmissions 20234. Part # 350001. Learn more. No speed, no vac advance & 1,200 RPM Performance Transmission and Drive Train Automatic Transmission Vacuum Modulator. zc uy fb nx go mq ql ka fc ij