727 Torqueflight low reverse shaft o'ring

Hi all,
I believe the o-ring on the low/reverse shaft in my 727 is leaking. this is a 74 trans in my 71 GTX clone. Leak seems to be coming out of the shaft hole in the housing above the pan, at first thought it was typical pan gasket issue but not the case. Wasted time messing around with that instead of diagnosing the leak clearly.

Im wondering if one can turn the rear tailshaft housing and not have to remove it complete so the retainer tab of the housing clears the hole so the pin can slide back and also if once pan is off one can "reach around" the valve body to push on the pin inside the case to get it to slide out the rear hole to replace the o-ring (s).

I've never done this and haven't pulled a valve body off a trans in 30 yr's so Im looking for clear input and experience here! I've found some threads addressing this but nothing that clearly says its doable like Im thinking. I love the ones that say "just break the housing tab" for clearance.....

thanks all!

Evan

I've done it, numerous times on later models with the OD unit, but I dont see why it cant be done with a simple 72 - 904 trans

No need to disassemble it. Clean it good with brake clean. Then RTV in the pin bore applied with a putty knife will stop it.
Doug

No, the park rod extends into the tailhousing and will prevent it from turning. As suggested, clean the end of the shaft and seal it with RTV. Works best if the fluid level is drained to below the shaft.

OK, thanks for the tips.

MY old high school teacher / Mopar racer friend, - from Wikipedia below:



who lives up the street from me suggested possible tailshaft housing gasket as well as shaft o-ring and the fixes are:
1) slight tap - veeery light - (.060ish) on the shaft to re-seat o-ring
2) tap, clean and RTV hole plus remove tailshaft housing and new gasket there too - DONT break tang off as some fixes show being done
3) pull trans and reseal shaft on bench

will try the first two and see how it goes. I wonder if you can get behind the inside end of the shaft & push it out the hole w/o removing valve body. I also dont know if that'll make the low band "fall apart" & then not be able to reassemble - dont want to go down that road.

If your going to remove the tail shaft housing and replace the gasket

Why wouldn’t you pull the valve body , loosen the rear band adjustment , push the pin out using your fingers on both ends as to not push it out all the way , just enough to expose the o-ring , and replace the o-ring ?

It really isn’t that difficult to do - Even if the rear band strut came loose or fell out , you can pop it back in contrary to what you read on the internet

I have done a handful for myself and friends , I am no transmission expert

Fear - lol! dont want to create more of a screw up than a repair. not sure how the rod into the tailshaft goes in did see a video on it, looked like it required some alignment of some sort) and anything else that might go wrong - so yeah - just fear!

You will not screw it up, only alignment needed is to rotate tailshaft while pushing park rod into park pawl and it drops right in. Sometimes you get lucky and is falls in, or line up pawl while tailshaft is off. Easy fix.