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  1. T-400 Park Brake assembly

    Transmission - Rearend
    Hi guys I'm chasing a park brake for a TH400 or need to know if the 4L80e unit will fit on. The unit i'm after would have come out of a late 80's P30 or GM motorhome. Can anyone help?
  2. T-400 Reverse & 3rd gear issues

    Transmission - Rearend
    Good Morning all, It's been a while since I've posted here, but this issue is throwing me a curve ball. I rebuilt my TH400 a little over a year ago with the upgraded clutches and steels. I also dual-fed the direct drum by removing the second teflon seal and plugging the main feed hole right of...
  3. Installing T-400 into 89 Silverado removed 700

    Transmission - Rearend
    Hello All, I am working on installing an TH400 into an 89 Chevy Silverado that previously had the 4 speed transmission (TH700) with the TV cable. Where is the best place to install the vaccuum line for the modulator and is the wiring there for the down shift relay? Any help on this would be...
  4. How T-400 works?

    Transmission - Rearend
    OK, I have been driving manuals for years and like how you can slow down by simply letting off gas, upshifting, because the gears are "locked" there until you tell it what to do. Today I seafoamed my motor and was running around high rpm and noticed with my TH400, first gear does this! It...
  5. T-400 won’t shift

    Transmission - Rearend
    I have a TH400 in a 34 Coupe. I ran it hard in 1st gear until the governor shifted to 2nd. Now it won’t shift out of 1st and when you let off the gas the tranny doesn’t hold the car back it goes into a coast. There is no fluid in the vacuum line at the modulator, vacuum line is good. Level is good.
  6. LS1 with old school transmission?

    Transmission - Rearend
    Hello, 2 months ago i did a swap my 91 caprice's engine to ls1 . my transmission was a 700R4 and i had difficulties fabricating the TV cable but finally did it. last week in my way to home in the highway the third gear went off, i was cruising at 120km/h at normal rpm. So i need an advise in...
  7. Newbie looking for help (is there any other kind?)

    Introduce Yourself
    Greetings Rodders! I've been a GM guy my whole life, which is funny, because the the only car I've driven for any length of time was a 1967 Cougar. I have two 1967 Camaros - one is for sale, because I finally bought my dream car - 1968 Charger. Once the Camaro is gone, I can finally get to...
  8. T-400 has lost reverse. Suggestions?

    Transmission - Rearend
    We have a th400 in an RV manufactured by Chevy and Fireball Industries. It is 31 years old. It will not go in reverse. We checked with a pressure gauge and everything is within normal ranges. No problems going forward. We think the problem has to do with a broken band inside there. The...
  9. T-400 VB Mods

    Transmission - Rearend
    New to rebuilding the TH400. got one that was previously gone through by another builder and I have found some of the mods done that are common. One I'm trying to figure out has to do with the 1-2 accumulator valve in the valve body. the ATSG book shows 3 configs, 2 of which have a spool...
  10. T-400 Slipping when shifting?

    Transmission - Rearend
    Hey everyone, I just rebuild my 355 SBC, and the engine runs great. Plenty of power. The transmission has a Hughes 2500 stall converter, a B&M Street and Strip Transpak, and a B&M Unimatic shifter. What's weird to me, is when I really get on it in 1st gear and slap it into second gear, it...
  11. T-400 slips in drive but has reverse after rebuild

    Transmission - Rearend
    Good Morning, Last week I rebuild my 400TH, it had been slipping in 2nd and 3rd before the rebuild. I found plenty of burnt clutches that I replaced along with a few bushings and seals. Hard parts were alright with little signs of wear. I put the transmission back in yesterday put 6 quarts in...
  12. Vacuum hookup on T-400 transmission?

    Transmission - Rearend
    I was wondering if some had a picture of where to hook up the the vacuum modulator to the manifold? I replaced the transmission in my 89 suburban with an th 400 and need to hook up the vacuum modulator but not sure where is the best place to hook it up at. a picture would be nice.:) thank you...
  13. T-400 problems

    Transmission - Rearend
    I have been cruising the forums and can't find any help so I finally decided to join here as you guys have secretly helped me in the past. haha. I Have a TH400 tranny that i pulled from a running driving vehicle. I replaced the pump gasket and put a B&M shift kit in it. It then sat for a few...
  14. My T-400 Tranmission Will not go into any gear.

    Hotrodding Basics
    I recently dropped a SBC (350) into my 1980 camaro, the transmission had been sitting out of the car for about 8 months, But when i drove it last, it shifted fine, so why it would stop working out of the blue is beyond me. I did remove the oil pan and change the gasket/filter, but I thought I...
  15. T-400 intermittent squeak rattle in park and drive

    Transmission - Rearend
    hello everybody. i posted a question before on hotrodders, and got some awesome help. so thankful for this site. i've got a new problem, this time with my transmission. (i think) I have an '85 chevy 3/4 ton 4x4. engine is a 402. tranny is a th400 that works great aside from being a little slow...
  16. T-350 trans troubles

    Transmission - Rearend
    First off I'll say I googled this for hours but no one has the same problem. This is my setup th350 in 64 nova, tranny is by redneck racing they say it's good upp to 850hp, has hard drum sprag ect, manual valve body, trans brake. This was how my night went at the street legal drags first...
  17. 77 turbo 400

    Transmission - Rearend
    I installed a used 400 turbo, but it will not shift. I have checked the govener, and installed a new modulator, that I have adjusted 2 times so far, but it still does not shift. Any help will be nice