Moparts
727 tranny that won't stop seeping. Arrrrrrrrrrrrgh!
Posted By: moparjo68
727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/28/11 10:56 PM
Hello. Have been reading in the Moparts archives about the best tranny pan gasket to use. Have already made sure leak is NOT from higher up, its at the pan. I bought the extra deep steel tranny pan from Mopar and have already tried various gaskets but no luck. I was then reading about the anti crush gasket offered by Chrysler dealers. My biggest concern with that gasket is about how much torque do I apply so I won't strip out the bolt threads of the transmission? I noticed alot of caution concerning this gasket because it was thicker than normal.
I know the shop manual states to torque the bolts 150 inch lbs but what would I torque the bolts for this gasket?
Posted By: John_Kunkel
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/28/11 11:16 PM
Use the same 150 in. lb. torque for the new style gasket.
Posted By: pishta
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/28/11 11:23 PM
I know you said it was from the pan, but there is a rod in the back of the trans body that the servo arm pivots on, I had a leak there and it took me while to figure it out, as well as the usual suspects, dipstick seal and speedo pinion and kickdown/selector lever O-ring leaks.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/29/11 12:48 AM
I've run my hand above the pan all around the corners and its dry. I placed a new o-ring on the dipstick tube. The wet begins at the gasket down. I've even looked above the pan with a mirror and no signs of wet. I would like to do this gasket replacement thing ONE MORE TIME. Although, the new tranny pan is a god send with the drain plug. HOW NICE!!!!!!!
Posted By: scratchnfotraction
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/29/11 01:35 AM
the new pan gasket part #2464324ac IIRC
did you get the deep pan extention? with that pan?
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/29/11 03:40 AM
Quote:
the new pan gasket part #2464324ac IIRC
did you get the deep pan extention? with that pan?
Yes I did!
Posted By: KY Charger
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/29/11 04:09 AM
If it is chrome sand off the chrome on the lip and use the rubber composite gasket with the gray permatex. I thought my gasket was leaking at one corner and then my little light bulb lite up and noticed it was my dipstick o-ring that was leaking.
Posted By: JohnRR
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/29/11 02:35 PM
Quote:
If it is chrome sand off the chrome on the lip and use the rubber composite gasket with the gray permatex. I thought my gasket was leaking at one corner and then my little light bulb lite up and noticed it was my dipstick o-ring that was leaking.
What he said , if the pan is chrome sand the chrome off the gasket rail or you'll never get it to stop.
I chased a trans leak on my truck for 2 years , turns out it was the fittings for the cooler line threads into the trans case .
Running your hand on the case is not going to find the leak , clean the trans, run it and then put baby powder on it, you'll find the leak.
Posted By: deansrr
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 06:01 PM
are you using anything besides the gasket to help seal it? I always use weatherstriping glue to attach gasket to pan and then right stuff on gasket and never have a problems with aftermarket pans
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 06:42 PM
The new pan from Mopar is steel, not chrome. From reading the archives about leaky pans, the general advice given was the gasket was suppose to do the sealing, not the chemical applied.
I read about the guy who rebuilds hundreds of transmissions a month using nothing but plain cork gaskets...........and never a leak. Well, what the heck is your secret. Cork didn't work for me.
Posted By: dOoC
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 06:48 PM
Quote:
Well, what the heck is your secret. Cork didn't work for me.
NO real secret ...other than a dead straight and flat pan rail. AND not OVERtorquing the bolts. CORK has always WERKED furr me ....
I also like the cast alum pan ... those pan-rails are always dead-straight ....
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 07:38 PM
What brand is your cast alum pan?????????????????
Posted By: BDW
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 07:51 PM
I know you think it's the gasket, so did I. Replaced the gasket 3 times.
Finally figured out it was leaking from multiple other places.......
NSS gasket bad
Pivot pin
Selector seal
Posted By: scratchnfotraction
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 09/30/11 08:05 PM
try the Mopar black ATF/RTV when useing a sealer,I use it with my cork gaskets
dont over torque it and let cure over night
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/06/11 12:30 AM
Quote:
I know you think it's the gasket, so did I. Replaced the gasket 3 times.
Finally figured out it was leaking from multiple other places.......
NSS gasket bad
Pivot pin
Selector seal
You were sooooo right. It was coming from somewhere other than the pan gasket. It was seeping around the pivot pin. I just didn't want to believe it, 'cause I just spent $450.00 bucks having the tranny rebuilt.
I crawled under the car last nite, stayed there for about 30 minutes to look for leaks. And there it was........seeping around the pivot pin. I was relieved to find the leak........then mad as heck that the tranny guy either overlooked or just neglected to replace this 10 cent o ring. Thanks alot Alan Willis, with Willis Transmissions in Owensboro, KY. I appreciate for all the extra work you caused me. 
Posted By: scratchnfotraction
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/06/11 04:05 AM
makes you wonder how much other stuff he overlooked,did not R&R and replace parts
i have jacked rear of car up,cleaned with brakeclean,air dry it with the airhose,coved good with the Mopar Black ATF/RTV and let dry over night.
thats stuff will seal up with it wet with atf,some great stuff for the bent/out of round dip tube and o-ring as well.
Posted By: JohnRR
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/06/11 02:54 PM
Quote:
makes you wonder how much other stuff he overlooked,did not R&R and replace parts
Not overlooked but not replaced to increase the bottom line , the trans will live past the warranty period .
jack up the rear of the car , clean the area real good , dry it and smear it with a good RTV...
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/12/11 01:56 AM
Spent the day taking tailshaft off of transmission to access the pivot pin o ring. O ring was as brittle as an old cookie. Brittle and broke to pieces. While I had the tailshaft out, I cut off the dog leg that keeps the pivot pin from sliding out. I am going to make a brace and create a "stop" for the pivot pin. So next time this happens, all I have to do is drop the pan, unbolt the "stop" brace that I made and slide out the pivot pin. A lot quicker. Has anyone done this?
Posted By: BDW
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/12/11 03:06 AM
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
Posted By: JohnRR
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/12/11 03:46 PM
Quote:
Has anyone done this?
Why? It's not like you'll be doing it again anytime soon .
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/13/11 04:35 AM
Well, thats true but Chrysler should have designed it this way in the first place. This part of the tranny is prone to leaking and taking off the tailshaft is a royal pain. Especially lying on your back with roughly two feet of working space. I know I could have tried the rtv silicone method but I chose not to go that route.
Posted By: bboogieart
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/13/11 05:24 AM
The thing is; they were never intended to last 40 + years. The fact so mant did says the Chrysler engineers did a good job.
Posted By: scratchnfotraction
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/13/11 11:59 AM
dont the tail shaft 'capture" the pin and hold it into the case from working its way out?
Posted By: JohnRR
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/13/11 02:21 PM
Quote:
dont the tail shaft 'capture" the pin and hold it into the case from working its way out?
In his case it doesn't anymore ... 
Posted By: BDW
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/13/11 10:52 PM
I'll jump back in here and ask a couple stupid questions:
1) Do you have to pull transmission from the car to pull the tail-shaft?
2) If you did cut off that ear that holds the pin in, would the pin slide out so you could replace the O-ring?
If the answer to both the above is yes, then I could see the benefit to trimming the ear, and then adding a bracket to the bolt to hold the pin in.
Wouldn't this be an easy fix for us shade-tree mechanics would don't want to pull the whole tranny?
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/14/11 03:10 PM
Your questions aren't stupid and I'll post pics (as soon as today or this weekend) and show what I did and how I fixed it. I was VERY PLEASED with the results. Joe
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/14/11 03:20 PM
Quote:
I'll jump back in here and ask a couple stupid questions:
1) Do you have to pull transmission from the car to pull the tail-shaft?
2) If you did cut off that ear that holds the pin in, would the pin slide out so you could replace the O-ring?
If the answer to both the above is yes, then I could see the benefit to trimming the ear, and then adding a bracket to the bolt to hold the pin in.
Wouldn't this be an easy fix for us shade-tree mechanics would don't want to pull the whole tranny?
1) No, you would not have to pull the transmission to remove tailshaft. You can also cut dog leg off w/o removing tailshaft. Metal is very easy to cut with hacksaw blade.
2) Yes, once the dog leg is removed, the pin will slide out far enough to remove old o ring and install new o ring. I would not slide pin out any farther than pan rail lip of tranny. I will post pics of what I substituted to hold pin in.
Posted By: bboogieart
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/14/11 06:20 PM
Quote:
I would not slide pin out any farther than pan rail lip of tranny.
This would be my concerne as the pin holds a lever in place and you might not get it back in. Then you are tearing it down.
Posted By: dOoC
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/14/11 06:24 PM
WHY are you doing this YOURSELF ?
The so-called REBUILDER who did this should be the one changing this O-ring.
Posted By: pishta
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/14/11 10:54 PM
Quote:
Quote:
You were sooooo right. It was coming from somewhere other than the pan gasket. It was seeping around the pivot pin. .....
Ooh Ooh, did I call it or what! 
Glad you found it. Leaking cars suck especially on new concrete driveways!
Posted By: scratchnfotraction
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 01:14 AM
Quote:
Quote:
Quote:
You were sooooo right. It was coming from somewhere other than the pan gasket. It was seeping around the pivot pin. .....
Ooh Ooh, did I call it or what!
Glad you found it. Leaking cars suck especially on new concrete driveways!
why yes you did! and yes it does! 
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:15 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
Here is the pic of dog leg cut off from tailshaft. When I pushed out pin to replace o ring, I pushed it out past tranny pan rail lip. It would not push back......like there was a stop preventing it. So I removed pressure on pivot pin by backing off band adjustment nut. Then it pushed right back into place.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:18 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
Then I needed a rod of some sort..........very stiff so as not to give to hold back the pin. I found in my box of parts a brace.........maybe once used to brace a dash.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:20 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
I cut on the brace and tweeked it and bent it in a vice 'till I got it down to size.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:23 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
I bolted the brace to the auto tranny shifter brace (not sure if this is proper name) and the other end of brace is NOT pressed against pin. There is approx. 1/8 inch gap between end of brace and pin.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:25 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with. [/quote:
Another pic of the brace by pin
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 03:30 AM
Quote:
Does seem like you could add a piece to the bolt above the dog leg once you cut it off.
Post what you end up with.
With the 1/8th inch gap, pin can slide back and forth like original set up. When o ring starts leaking again, you don't have to remove tailshaft. Just remove pan and brace, you're done in a fraction of the time.
Posted By: 68_CONV_300
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 02:29 PM
nice work !
Posted By: BDW
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 02:37 PM
Looks good, I was actually thinking you could make a Z-shaped piece out of flat stock, and use the bolt right above the section you cut off. I guess it might be hard to get a sharp enough bend in such a short distance.
I'm still confused on how you can replace the O-ring without removing the rod?
With the valve body removed, can you slide it all the way out?
Posted By: 68_CONV_300
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 02:38 PM
yes ... if you drop the pan and disassemble the low/reverse band linkage you can slide the pin out, if the tab is cut off the tailshaft housing.
Posted By: moparjo68
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 10/15/11 04:48 PM
Quote:
Looks good, I was actually thinking you could make a Z-shaped piece out of flat stock, and use the bolt right above the section you cut off. I guess it might be hard to get a sharp enough bend in such a short distance.
I'm still confused on how you can replace the O-ring without removing the rod?
With the valve body removed, can you slide it all the way out?
I tried to make the z shaped piece you mentioned but found it more difficult. I was not satisfied with end results.
The rod is being pushed out, not removed. Once pan is removed, you can push pin from opposite end and push it out. I didn't have to remove valve body. I just had to get tranny filter out of the way. I had to use a cheater piece (a 1/4 in socket extension) to get pin to push out far enough. Then with pin pushed out, you remove old o ring and place on new one. Then push pin back in. I had to gently tap pin with wooden dowel rod to get back in. New o ring was causing small resistance. I would remove pressure from band before you begin as a pre-caution just in case pin slides out to much.
Posted By: closer9
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 02/12/12 06:06 AM
Can someone tell me what size O-ring is used for the pivot?
I got the fancy gasket from the dealer, and figured while I was in there I would replace this O-ring. I think I've got an old dash bracket to make a stop for the pin on the outside. I will also finally get around to replacing the kickdown shaft seal. I spent weeks looking for one. Just happened to be in NAPA one day asked about it. $1.50 on the shelf. Guy on the phone told me part number on their website was no good. No one else even had a clue. Found a guy on ebay selling them for $15 + shipping. The kickdown seal didn't appear to be bad or leaking, but I did replace the shift shaft seal, and figured that one needed replaced too.
Posted By: MoparDonny
Re: 727 tranny that won't stop seeping. Arrrrrrrrrrrrgh! - 02/13/12 04:08 AM
Piece of 3/4 x 1/8 flatbar in a vice bent to a 90 deg angle, drill 3/8 hole for tailhousing bolt to go through. done, simple clean. I've done alot of these. usually I'll service the trans or be servicing it when I notice the leak but I did my own without pulling the pan about 2 years before I rebuilt it. For all intents and purpose, yours will be just fine now, but that rod looks a bit bulky. At least it won't leak anymore though, feels good to solve that problem.