OK, tranny gurus...explain this:
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Joined: Dec 2002
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From: Pensacola, FL
OK, tranny gurus...explain this: I have broken my Forward Clutch Apply Piston. Anybody ever heard of the heavy duty version of this (steel vs. aluminum stock piece) cracking? The tranny tech says he's never seen this happen before, especially on the heavy duty piece. He says that there must have been an incident, or many incidents, of super high fluid pressure for tha piston to split like it did. There was a hairline stress crack across about half the apply surface that allowed fluid to pass through and wet the 3rd gear clutches and 2nd gear band. $900 in parts and labor later and I'm good to go. Luckily, this was all done under warranty. I'm just curious if anyone else has heard of this particular hard part being destroyed?
The forward aluminum pistons crack occasionally, that is why I have them Cryo treated (deep freeze with liquid nitrogen at -320 F), to prevent them from cracking. I have not seen a steel one crack.
I,ve seen more than a few crack. Fwd piston and over run pistons. I've been taking the quick way out. Been installing the molded steel when ever I do a vaccum mod. I know you told me once that the aluminum is better because of the weight but I dont know of a place around here that has liquid N2.
Mec
I,ve seen more than a few crack. Fwd piston and over run pistons. I've been taking the quick way out. Been installing the molded steel when ever I do a vaccum mod. I know you told me once that the aluminum is better because of the weight but I dont know of a place around here that has liquid N2.
Mec
Thread Starter
TECH Regular
Joined: Dec 2002
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From: Pensacola, FL
Originally Posted by Pro Built Automatics
I have not seen a steel one crack.
If you did find a steel one cracked, where would you look to fix the condition that caused it? 
