727 leak at rear and not sure how to fix

[Justasgood]

So my Torqueflite 727 has an ongoing seepage at the rear tail area. It looks like someone filled a hole with Silicone(?) and it continues to allow fluid to seep.

What was this hole intended for and is there something missing or needed?

Best way to address this?

Searching online only shows what I think is a “Packing Lock assembly”? Perhaps that is a Parking lock assembly?

Anywho, any insight or suggestions would be greatly appreciated.

Thanks,

Kurt

 

[icetech]

This should be your issue.. can fix it in car, will take 2 hours or so..

727 leak -what’s this?

This leak is from the back side of the transmission body. The bolt head is bolting the tail section to the main body and the leak is at that found thing just below. What’s the round thing and what’s the fix?

www.forbbodiesonly.com

 

[Justasgood]

So if I drain the fluid, remove the existing silicone and clean and dry the area, can I reseal from the exterior with something like “The right stuff”?

 

[Rebelrouser]

The area you mention is the pin that holds the rear band, it is supposed to have an O-ring on it. Lot of guys myself included put a dab of silicone just to make sure it does not leak. To pull it completely out you will have to remove the valvebody to gain access to the band strut to line it up correctly when you put the pin back in. You should be able to clean really good and silicone it again and it should stop leaking if it is the pin hole leaking. It should only leak when the engine has been shut off for a while and the converter drains into the case, while running the fluid should be below the pin hole.

 

[Car #4]

I had the same problem and couldn’t get it stopped from the outside. The real solution is to replace the O ring inside as mentioned in post #4.

 

[Bee1971]

It’s not a hard job - Just a messy job on your back - Lift sure would bee nice

You have to remove the tail shaft housing bolts and rotate the tail shaft for the tab to clear the pin
You DO NOT have to remove the tail shaft , unless I guess somehow the gasket got stuck or got damaged

Any linkage on the tail shaft remove

My local transmission shop gave me a used newer double style pin and the proper o-rings

I guess I reality I didn’t want to use silicone

 

[icetech]

It’s not a hard job - Just a messy job on your back - Lift sure would bee nice

You have to remove the tail shaft housing bolts and rotate the tail shaft for the tab to clear the pin
You DO NOT have to remove the tail shaft , unless I guess somehow the gasket got stuck or got damaged

Any linkage on the tail shaft remove

My local transmission shop gave me a used newer double style pin and the proper o-rings

I guess I reality I didn’t want to use silicone

View attachment 1556960

View attachment 1556961

I didn't know you could just rotate the tailshaft, very good to know

 

[Justasgood]

Lift - check
Where can I get the double 0-ring pin?

 

[zyzzyx]

Just remember to remove your speedometer pinion because if you break it while moving the tailshaft backwards
it will be a P.I.T.A!

 

[Justasgood]

Part name of Pin?

 

[1 Wild R/T]

Part name of Pin?

Rear band anchor pin

 

[Justasgood]

Can these be found with the double o-rings?

 

[Bee1971]

Just remember to remove your speedometer pinion because if you break it while moving the tailshaft backwards
it will be a P.I.T.A!

I didn’t even remove the speedometer cable when I rotated the tail shaft housing - You only have to rotate it slightly , not pull back

 

[1 Wild R/T]

I've been rebuilding torqueflites on the side since the seventies... I've seen exactly one pin with the double O ring grooves.... It was from a mid eighties truck...

The reality is the single O rings are fine if they are less than twenty years old... Lots of younger rebuilders neglect to change the O cause they don't realize it's there...

If you pill the pin to swap it you could just put an O ring on the existing pin & you'll be find....

Or do what most guys do, drain a little fluid, clean it really well with brake clean & compressed air.. And fill the hole with silicone, allow to dry overnight & refill with fluid...

That's usually good for years but depending on how good of a job you do it does slowly breakdown & fail..

If you've gotta have two O rings a few minutes on a lathe & you'll be all set...

 

[R413]

Lift - check
Where can I get the double 0-ring pin?View attachment 1556994

You don’t really need the double o ring pin, but it won’t hurt. It’s probably a 50 year old oring in your pin. Nobody ever changes the Oring.

if you are going to rotate the rear housing then remove the speedo gear so it doesn’t get damaged. DAMHIK

 

[icetech]

I "Think" i replaced my o-ring... been afraid to fill the trans yet.. cable shift trans with sooo many spots waiting to leak

 

[Bee1971]

Chrysler


Page 61- Figure 96

https://atoc.ru/uploads/manual/5fb79d619e567.pdf

 

[493 Mike]

Years ago I cut off the tab that retains the pin, dropped the VB and knocked the pin out to R&R the O-ring. Fabbed a different retainer to secure the pin. The next time the trans was out I swapped extensions back to OEM condition. I do not remember why I did not remove the extension in the first place except I was on my back doing the work? I still have 20 or so TF cores so extensions have become just more "parts".
Mike