I knew this trans was dead... TH350 Rebuild

Discussion in 'Transmission & Transfer Case' started by da_raabi, Apr 17, 2018.

  1. HotRodPC

    HotRodPC Administrator Staff Member

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    No worries. Trans fluid has more detegerent in it than anything. So long as it's clean trans fluid, it probably won't stain.

    Getting that piston down is a bit challenging since you only have access to 1 of the 3 O rings. Hopefully you didn't just hammer it on down in there. You can push while working the 1 small center seal but if you hammer it down, you're likely to have split a seal and Low 1 or Reverse won't hold as good as they should. You can also air pressure test that before you go any further to make sure. Flip the case over and one of the holes right under the back of the pan is the one you'll hit with about 30psi and notice what the piston is doing after you have the snap ring in place.
     
  2. da_raabi

    da_raabi Trailer Park Supervisor

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    I was gentle... Sorta. The Jeff Sessions instructions said you could gently hammer it down to get it it seated. I did my best to do that. I figured because the seals were flat seals, as opposed to lip type, that they were just stiff in the bore. I'll check with air this evening and make sure they hold.

    Is 30psi the max? My compressor does not adjust pressure well so it might very well end up higher than that.
     
  3. HotRodPC

    HotRodPC Administrator Staff Member

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    You can hit it with more than that, but don't hold it on there for long. I've done up to 90 before when I forgot to turn my regulator down. I do gently tap with a hammer handle and push some. Make sure you have plenty of trans gel or vaseline on all 3 seals. If you don't have trans gel, vaseline works just fine. It'll melt down. Just don't use grease. It tends to ball up in the trans fluid and can clog a dacron filter and it gets messy.
     
  4. da_raabi

    da_raabi Trailer Park Supervisor

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    Piston checked good. Put about 40psi behind it and up she popped. Held until I released the pressure. No hissing.

    So on I forged. Got the new rollerized ring gear installed, five new clutches, 5 4L60E "Turbolator" steels, and the new 4L60E center support. I was unable to measure the clutch pack clearance, but I figure it should be ok. Didn't even bother measuring output shaft end play. I gave the shaft the 'ol up and down and it just moved ever so slightly. My calibrated elbow said that was right where it needed to be.

    And the parking pawl ACTUALLY ENGAGES. I dunno what the hell the previous guy did, but the fact that the ring gear was so far aft that the pawl would not even engage is NUTS.

    I went to install the nice new metal thrust washer between the center support and the sun shell and discovered that they manufactured it wrong. They bent the tangs so sharply that the outside corner cracked and chipped. Every single one in the pack was like that! So back that goes... Because I rollerized everything I probably won't even need any of the damn things except that one. Pain in my balls...

    Anyway. I soldier on.
     
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  5. da_raabi

    da_raabi Trailer Park Supervisor

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    After some additional research I found that the "cracking" I saw must be typical of these parts. Below is an image taken from an entirely different eBay listing showing the issue that I found. Look at the tangs where they bend inward. See how they seem to be cracked? In metal work I always thought this was reason to reject a part, is it just normal for this part to look like that? Should I say screw it and just use the original plastic version?

    @HotRodPC @crazy4offroad ever seen this in one of your rebuilds?

    washer.jpg
     
  6. HotRodPC

    HotRodPC Administrator Staff Member

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    Yes, that's fairly typical. There's also a plastic version of that thrust washer made too. But you can roll with it if has the fractures at the bend in the tangs.
     
  7. da_raabi

    da_raabi Trailer Park Supervisor

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    Ok good to know. When I took them out of the package and saw that I went WOAH!

    Cool, so that means I can keep going on the rebuild tonight. Hoping to get all the way through the pump tonight, then work on the valve body tomorrow. If I get SUPER lucky, I might be able to work towards re-installation in the car this weekend. No promises though.
     
  8. HotRodPC

    HotRodPC Administrator Staff Member

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    The pump shouldn't take but about 30 minutes. Tear down, clean and reassemble with the 2 new piston seals. Don't even bother trying to change the front seal until you have it bolted in the case to hold it firm while you work the old seal out and tap the new one in. That's usually the last thing I do is install the front and rear seals.
     
  9. HotRodPC

    HotRodPC Administrator Staff Member

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    The Valve body will take you a bit. And I do agree, DO NOT TAKE IT APART, unless you have time to put it all back together. That way it all stays fresh in your mind and you don't sleep on it.
     
  10. crazy4offroad

    crazy4offroad Service Bullshit Filter Soon

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    Yep mine were like that. Didn't think twice about using them though and so far so good
     
  11. da_raabi

    da_raabi Trailer Park Supervisor

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    More details tomorrow... But it is finished.

    IMG-20180616-WA0000.jpeg
     
    Last edited: Jun 18, 2018
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  12. da_raabi

    da_raabi Trailer Park Supervisor

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    Got the trans back in and everything hooked back up yesterday. The job went smoothly, well at least until a 2.5" wolf spider strolled up next to me while I was under the car. Oh and it had BABIES ON ITS BACK. Of course I did not know this until I smacked it with a 1x4 and BABIES EVERYWHERE. Few things turn me into a bigger baby than one of my girls, but big ass spiders with babies on their back is one of them!

    I spent half an hour spraying anything that moved with spider killer.

    So anyway the results of the install were... ok. The trans seems to be functioning but my shifter is all farkled up. The original shifter in the car is a friggen slush box and I'm pretty sure I did not have the cable hooked up right. I'll be tackling that over the next couple days in the hope I can get things working right.

    I'm happy, but disappointed at the same time. Until I actually get this thing to slam through the gears and hold 3rd under load I will NOT be happy.

    Wish me luck...
     
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  13. da_raabi

    da_raabi Trailer Park Supervisor

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    Well that explains a whole lot. The damn nut inside the pan that holds the rooster tail on the shift shaft was loose. How the hell did I do that? It was an easy fix, at least until I proceeded to break the end off my nice new shift cable... So that's another $22 down the tubes. New cable will be here Friday. Ugh.
     
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  14. da_raabi

    da_raabi Trailer Park Supervisor

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    Got the new cable installed, as well as a new shifter. The old one was just way too sloppy. The new one is for a 700r4, but it seems to be working.

    Anyway I got to drive it today. It definitely shifts, although it seems to prefer manual shifting. Auto is ok, but it chattered in and out of 3rd a bit like it wasn't sure where it wanted to be. Im going to try adjusting the modulator to up the shift points a bit and see what happens.

    So far so good!
     
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  15. da_raabi

    da_raabi Trailer Park Supervisor

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    I've driven the car a few times now. It chattered third a couple more times, but has not done it since. I'm thinking it may have still been breaking in. Funky, but it seems ok now.

    It is interesting however that auto shifts are almost entirely unnoticeable. Can't even tell the car shifted. Yet, when I manually shift it bangs into the gears real nice and firm. Is this normal? Are the super soft auto shifts because I put all the check balls and the orange accumulator spring back in? It's a very strange sensation, reminds me a lot of those new variable-band honda transmissions that never shift.

    I manually shift 99% of the time because its more fun:dancingpoop: but I do wonder about those auto shifts.
     
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