E-Bodies.org Cuda Challenger Forum

Technical Shop => Engine, Transmission & Rear End => Topic started by: nsmall on April 21, 2021, 09:06:48 PM

Title: Will this transmission ever stop leaking?
Post by: nsmall on April 21, 2021, 09:06:48 PM
I have spent a lot of time and money trying to get my 727 to stop leaking.  New pans, new gaskets that were supposed to be leak proof.

Should I just toss in the  :whiteflag: and give up?  I know these cars are old, and I dont mind a drip, but lately I have noticed the puddles are growing to two about the size of a quarter after driving my car. 

The Main leak I am guessing is around the pan, but I noticed a drip at the speedo cable and at the trans cross member bolts.  I have even had two local "experts" work on it (charge me a small fortune) and I am :Thud:

Any advice?  Thanks
Title: Re: Will this transmission ever stop leaking?
Post by: Mrbill426 on April 21, 2021, 09:38:54 PM
It can drive you nuts.
Be sure and look around the shifter shaft, there is a seal around it that is prone to leaking and it will flow down around the pan rail.
Title: Re: Will this transmission ever stop leaking?
Post by: 7212Mopar on April 21, 2021, 10:59:51 PM
And leak at the safety switch.
Title: Re: Will this transmission ever stop leaking?
Post by: 1 Wild R/T on April 21, 2021, 11:19:05 PM
Rear band anchor.... :alan2cents:
Title: Re: Will this transmission ever stop leaking?
Post by: 7E-Bodies on April 22, 2021, 06:43:33 AM
It's like 727's were made to leak. I've had many. Currently have one, just rebuilt and am afraid of it as well. May be getting another car with a 727  :headbang: I fought a 727 leak on my U code 70 Challenger for years, later to find it had been leaking where the dipstick tube entered the case. Those tubes fit like saddles on sows. Piss poor design on Ma Mopar's part IMHO. Take a close look there.
Title: Re: Will this transmission ever stop leaking?
Post by: anlauto on April 22, 2021, 06:55:28 AM
YES...eventually it will stop leaking if you stop topping it up  :D
Title: Re: Will this transmission ever stop leaking?
Post by: 1 Wild R/T on April 22, 2021, 07:34:33 AM
I've had leaks, I've fixed leaks...  Most common points are the band anchor, the shift shaft & the dipstick tube.... The solution for the dip stick tube is use a modern design dipstick tube... You what it to look stock?  Reuse your dipstick with the new design tube... Just modify so the tube/stick length matches...

The band anchor gets a new O ring & the shift shaft gets a new seal...
Title: Re: Will this transmission ever stop leaking?
Post by: 7E-Bodies on April 22, 2021, 07:41:22 AM
@1 Wild R/T (https://forum.e-bodies.org/mlist/1-wild-rt_320) I swear I heard harp music when I saw this! I have a newly rebuilt numbers matching 727 ready to go into service and will definitely order one of these. I can't believe how sloppy the stock tube fits into that body. I'm starting to refer to 727's as the "Kokomo Kalamity".
Title: Re: Will this transmission ever stop leaking?
Post by: Scooter on April 22, 2021, 11:24:14 AM
^^^ Reminds me of the power steering setup on my old Ford.. when it stops leaving a puddle you are out of fluid.  :haha:
Title: Re: Will this transmission ever stop leaking?
Post by: tparker on April 22, 2021, 01:55:54 PM
Just to throw out an opinion. LOL. I think the first thing is to figure out where the leak is coming from. If you changed the pan and gasket, I doubt it would continue to leak if that was the problem. As mentioned there are a few places it can leak from so we gotta narrow it down. I would clean every thing as best as I could, then clean it better since I usually don't do a great job the first time. Then drive it around and then watch for the leaks. If it is slow, then I'd put some paper towels down to isolate where the drips were coming from then follow the wetness back to the source if possible. Maybe you already did all this. But is it coming from the front, bottom, sides, rear of the tranny? Might help diagnose it a bit better. :)

Good luck. Now you have me scared that mine will leak too.
Title: Re: Will this transmission ever stop leaking?
Post by: RUNCHARGER on April 22, 2021, 03:13:17 PM
It's just O-rings and gaskets, most important thing to do is find out where it is leaking first. Back when we drove these cars daily they didn't seem to leak. I think that sitting for days on end seems to make them leak.
Title: Re: Will this transmission ever stop leaking?
Post by: 7E-Bodies on April 22, 2021, 04:09:32 PM
Another problem is the stock pans. If the flange isn't laser flat (after 50 years of being bolted down) a leak is guaranteed. Being an OCD purist in most cases, I find it hard to shell out $250 for an aluminum that IMO is too close to the ground, but I may make an exception.
Title: Re: Will this transmission ever stop leaking?
Post by: nsmall on April 22, 2021, 11:15:19 PM
Thanks everyone I'll go out there and give her the old college try. :unitedstates:
Title: Re: Will this transmission ever stop leaking?
Post by: mopar jack on April 23, 2021, 05:58:06 AM
I found leaks at the front of the pan due to a weak area causing it to bow. I put a piece of flat bar across 2 bolt holes.
Title: Re: Will this transmission ever stop leaking?
Post by: 7E-Bodies on April 23, 2021, 10:47:38 AM
@1 Wild R/T (https://forum.e-bodies.org/mlist/1-wild-rt_320) my Mancini order is now processed. Thank you.
Title: Re: Will this transmission ever stop leaking?
Post by: dodj on April 23, 2021, 02:29:54 PM
@nsmall (https://forum.e-bodies.org/mlist/nsmall_145)
Your car is just marking it's territory.....
Title: Re: Will this transmission ever stop leaking?
Post by: 70 Top Banana on April 23, 2021, 06:11:09 PM
1 Wild RT- what kind of modern dipstick tube? For what modern transmission or an aftermarket tube??
Title: Re: Will this transmission ever stop leaking?
Post by: 1 Wild R/T on April 23, 2021, 06:43:28 PM
Quote from: 70 Top Banana on April 23, 2021, 06:11:09 PM
1 Wild RT- what kind of modern dipstick tube? For what modern transmission or an aftermarket tube??

Mopar started using them on Ram trucks in the late 90's... GM used that design for many years, it works... The aftermarket decided there was a market for our old cars... Follow the link..

https://www.manciniracing.com/search-results.html?query=transmission%20dipstick
Title: Re: Will this transmission ever stop leaking?
Post by: nsmall on April 23, 2021, 08:10:49 PM
Quote from: dodj on April 23, 2021, 02:29:54 PM
@nsmall (https://forum.e-bodies.org/mlist/nsmall_145)
Your car is just marking it's territory.....

Thats funny, thanks, I liked that one.
Title: Re: Will this transmission ever stop leaking?
Post by: Purepony on April 30, 2021, 09:18:31 AM
I've heard good things about the lubelocker gasket anyone try one ?
Title: Re: Will this transmission ever stop leaking?
Post by: 73chalngr on May 01, 2021, 05:51:42 AM
I was told by a mechanic if using a chrome pan to sand the finish off where the gasket goes .