TH400 Rebuild kits

Discussion in 'The "Juice Box"' started by 1969RIVI, Dec 1, 2018.

  1. 1969RIVI

    1969RIVI Well-Known Member

    Can anyone recommend a good rebuild kit for a TH400 trans? My current trans has a small leak at the tailshaft seal and a bigger leak coming from behind the torque converter so I'm guessing the main seal is compromised. I have a b&m shift kit that I will reuse.

    *question* my flex plate has a good wobble to it and I've been told it's probably cracked can that wear out the front seal and cause the leak?
     
  2. Nailhead Ronnie

    Nailhead Ronnie Do the right thing.

  3. Mark Demko

    Mark Demko Well-Known Member

    If it still shifts good, just replace the seals.
    The extension housing seal is easy, the convertor /pump seal isn't bad to do.
     
  4. Nailhead Ronnie

    Nailhead Ronnie Do the right thing.

    "Shifts good"

    Do you mean shifts good while running? Or the selector shifts good on a non running trans out side of a car?

    Sorry for the hijack
     
  5. 1969RIVI

    1969RIVI Well-Known Member

    When I first got the car 2 years ago it used to clunk going into reverse which I didn't think was right? This past season / summer it wasn't doing the clunking anymore (I replaced the fluid, extra deep derale pan with cooling tubes and filter at the start of the season). Towards the end of the summer it started to make a "shutter feeling" and "clicking" noise when reversing and now I loose quite a bit of fluid. I have to top it up every couple days.
     
  6. 1969RIVI

    1969RIVI Well-Known Member

    No worries Ronnie we're all hear to learn and help each other!
     
    Nailhead Ronnie likes this.
  7. Nailhead Ronnie

    Nailhead Ronnie Do the right thing.

    Give me a couple hours if you still havent found one and ill give you a phone number of a guy from the olds forum who sells kits. He is very nice and people use him over there..
     
    Last edited: Dec 1, 2018
  8. 1969RIVI

    1969RIVI Well-Known Member

    Ok that would be great! I basically wanted to throw out some feelers to the community on what kits they've used in the past to rebuild the th400. And which ones to stay away from. I figured I would order a kit and then drop the trans in the spring and rebuild it myself. I have no idea what kind of abuse it's been put through so I figured a full rebuild I would be safe rather than just doing the seals and then the clutch packs go on me later
     
    Nailhead Ronnie likes this.
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You intend to rebuild this yourself?
     
  10. 1969RIVI

    1969RIVI Well-Known Member

    Yes I do Larry, I've watched several tutorial videos and read tons of literature on how to do it. I will also order a manual along with a full rebuild kit to help me along the way.
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

  12. 1969RIVI

    1969RIVI Well-Known Member

    Ok thanks Larry I appreciate your input! I'm not sure how to move the whole thread??
     
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Just PM one of the moderators.
     
  14. 1969RIVI

    1969RIVI Well-Known Member

    Ok thanks!
     
  15. telriv

    telriv Well-Known Member

    An even better Sprag is the one out of a 4L80E as it's a 40 or 42 element. If you don't mind a somewhat hard shift use the flat clutch plates instead of the wavy stock ones. Most ALL the good aftermarket clutches are the same, Reds, etc. Most ALL the seals, o-rings, etc. are basically all the same in most of the re-seal kits. Nothing super fancy here.
     
  16. 1969RIVI

    1969RIVI Well-Known Member

  17. TexasT

    TexasT Texas, where are you from

    I would get a "paper n rubber" kit that will have the seals and vb gaskets. I generally reuse steels if they aren't too spotted and burned. I hit em with some Emory cloth and them brake cleener. Give em a crosshatch pattern. I do the same crosshatch on the drum after checking and making sure it is flat with a straight edge and flashlight. Something shown in the transmission bench videos on YouTube. And the crosshatch is shown in the transgo instructions. It takes more time than just putting in new but I have more time than money. I'd I was doing production work id just charge more and install new, but these go in my stuff.
    I'd use the BorgWarner hd clutches in the direct. The tans should be fine in the other clutches but that is up to you. They aren't "shifting" so they are either on or off. The direct is a shifting clutch so it has to take much more abuse. I like a carbon band. There are other fancy materials but these are less expensive and have worked for me.
    You need a way to compress the clutch piston springs to get the pistons out. There are fancy tools but I use some rigged up stuff and a hf press or a threaded rod and some metal to get them compressed. You also need a good snap ring pliers. I have a nice Wilde brand I bought off eBay for about $22 shipped to the house.
    Also need a way to remove and install new bushings. Again I use the hf press and whatever I can find that fits the size of the bushing. Some I drive out with a punch and hammer and some can be pressed.
    I think of you can remove and install one you should be able to overhaul it. I will post up some pix of my stuff to give you ideas. C__Data_Users_DefApps_AppData_INTERNETEXPLORER_Temp_Saved Images_$_1(1).jpg
     
  18. 1969RIVI

    1969RIVI Well-Known Member

    Thank you for the info Texas T I really appreciate any pics, tips or suggestions. The reason I was leaning more towards a full rebuild is I have no history on the trans, I'm not sure if everything in there is original from 69 or if its had anything replaced along the way.
    To be honest I'm not even 100% sure its the original trans. I do know the previous owner did put a B&M 2400-2800 holshot torque converter, B&M shift kit and B&M ratchet/slap shifter in it and I did the fluid, filter and new pan last season. It's a cruiser car for me and I may take it to the track the very odd time so I don't need any crazy shiftingbut would like something that can take the abuse when I want to play.
     
  19. 1969RIVI

    1969RIVI Well-Known Member

  20. TexasT

    TexasT Texas, where are you from

    Some pix of the 4l60e I'm working on. And a pic of the press I have. You want to use the rings that aren't cut for best seal. They sell fancy tools for installing them it I just use a funnel spout to stretch em out and some plastic from a soda bottle and hose clamps to "size" em. WP_20181128_18_16_02_Pro.jpg WP_20181128_009.jpg WP_20181128_015.jpg C__Data_Users_DefApps_AppData_INTERNETEXPLORER_Temp_Saved Images_IMAG3935.jpg
     

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