[desman]

Hi, I'm new to this forum and was wondering if anyone can tell me if there should be any leakage past a new set of cast iron rings and teflon rings on the stator shaft when checking for proper clutch piston operation using 25# of air? I was testing the direct clutch piston seals and the forward clutch piston seals using 25#compressed air (via the oil passage holes on the pump) and though there is no leakage past the rubber seals, there is some leakage past the new cast iron seals when I test the direct clutch piston. There is also some leakage past the teflon rings when I test the forward clutch piston. This is my first th350 rebuild and I'm using the Ron Session book. Is this a problem and can it be corrected if it is? Any help would be greatly appreciated. Thanks, Paul

[BOBCRMAN@aol.com]

is the bore worn where the original rings were riding? this is common on older 350's with worn out center bushings. Also did you supply plenty of lube before testing?, lube helps seal also.

[desman]

There does not appear to be excessive wear in the bore that I can feel or see. The bore is shiny where the old seals had been riding, but it is not worn to any extent that I can tell. I did lube the seals but I'll try using more and see what happens. One test I did do was to remove one of the cast iron seals from the stator shaft and I placed it in the bore, where it would seat normally. Then I took a flashlight and shined it on one side of the seal while I looked at the other side of the seal for visible light between the seal and the bore. There was a tiny spec of light but it was where the ends of the seal met and interlocked. Does this indicated excessive wear? Thanks for the help!

[b/w72]

trans fluid is more dense than air so it will not leak by as bad. I think as long as your pistons pump up with air supplied to them then you should be all set. I had a similar problem with the last trans I did, my trans guy looked at it for me and told me to run it. It s been working fine so far

[dklong]

desman you'll probably will get some air leakage ,when testing the forward and direct clutch packs on the pump, due too the clutch packs not sitting 100% square on the pump, when installed in the trans, with good bushings everthing should be true and making a good seal. the bushings on a th350 are a common problem, such as seal leakage ie teflon rings and iron rings. when rebuilding always replace the torque converter bushing, center support bushing, end case bushing, and tail shaft bushing. and always check the clutch and drum bushings too and replace if nessary, on the end case bushing , before removing measure the height then remove and when installing ,install the bushing at the same height, same goes with the clutch and drums bushings.

[desman]

Hey, this is great info and real insight on this problem. So far the rest of the rebuilt is going good (clearances etc..) I'm using a Transtar rebuild kit and it seems pretty complete but did not include the bushings that go inside the stator shaft. Is that normal for rebuild kits? The middle bushing (the most difficult one...murphy's law) looked suspicious so I took it to a shop and they put all 3 bushings in. I will be sure to replace those other critical bushings too. I'll have a few more questions as this proceeds but thanks a million for the current info. I appreciate the help.

[dklong]

some rebuild kits only contain seals, while others contain seals and clutches. bushings are sold sepreate