Discussion in 'The "Juice Box"' started by HeavensDevil, May 15, 2020.
It is rubber and one side is smooth and the other has small grooves.
Low reverse piston seal?
I lost reverse pulling out of the garage but forward gears are OK.
Should have checked if I have engine breaking before pulling the pan
Screw it, pulled it.. Here we go again
Well hopefully it's a cheap fix!
Got it torn apart today and the case is junk, how does this even happen!?
To the untrained eye, how is it junk?
Are those the case lugs all snapped off where the snap ring goes in?
Yes, exactly right !
Well I'm not a trans expert but I'm going to say the case is junk. Even if you erre to try and weld the lugs back on it will be weak and probably fail again. As for what caused that umm not sure. The trans experienced some kind of extreme force forward to make that happen were you out doing neutral drops lol
Maybe this will help?
Larry, that will help for his next case but I don't think it will do anything for him on his current one since the lugs are already snapped off. I wish I had a known about that when I did my rebuild I would have bought it and put it in just as insurance
I realize that. I was suggesting that for his next case. I remember reading about this same problem and Googled "THM 400 Case saver".
I figured you knew that Larry I was just being captain obvious . I assume the trans has to be out of the car and fully disassembled again to put that case saver in?
I would assume so. I'm sure you are way more familiar with that than I am.
The OP is working on a THM 350 here guys.. the case saver is for a 400.
Ooops, Thx Jim.
Not sure if this applies.
I have seen this before, it’s caused by excessive line pressure. Make sure the pressure regulator valve in the valve body is clean. Make sure the modulator valve in the case is free to move. Make sure the vacuum modulator itself isn’t bent.
Have any of you in readerland noticed the way the steel vacuum line is shaped with the bent dip just ahead of the vaccine modulator? Every wonder why it’s there? I’m sure many of you have spent many a sleepless night tossing and turning, your mind unable to relax until the mystery is solved. Get ready for a full night sleep!!!
The purpose of the low area of the vacuum line is to prevent condensation from building up in the modulator. All it takes is a couple cold starts, short trips, and moisture collects in the line. If the steel line tunnels the water directly into the modulator, bad things can happen. If the water collects in the modulator, and then freezes, the modulator valve is locked solid. Next cold start, high engine idle, drop the trans into reverse, and line pressure will go thru the roof. If your lucky, it will break the piston. If your unlucky, it will blow out the case lugs for the snap ring. If your REALLY unlucky, it will split the case in the area of the low/reverse clutch.
Well damn,,I will get back at it next weekend, thank you sir..