Cast Iron Push Button 727 leak

Sixpactogo

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My 60 Dart has developed a leak around the kick down lever. Anyone have experience with replacing the seal? Pretty sure I need to drop the pan and valve body to get at it. Is it a standard O ring or does it take a special seal.
Any tips on this operation would be appreciated.
 

sb61fury

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Do not feel bad mine is leaking also but my dad told me its a seal . I wish I knew some one that knew about these and I would take it to them . I would talk to some one who has worked on these before and see what he or she has to say Good luck to you . I know transmission leaks suck and I hate that mine it doing it . I even tried transmission stop leak and it does not do a damn thing to help so I will not spend my money on that but with mine it is a seal that has gone bad but I do keep an eye on the level of the fluid
 

Sixpactogo

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Do not feel bad mine is leaking also but my dad told me its a seal . I wish I knew some one that knew about these and I would take it to them . I would talk to some one who has worked on these before and see what he or she has to say Good luck to you . I know transmission leaks suck and I hate that mine it doing it . I even tried transmission stop leak and it does not do a damn thing to help so I will not spend my money on that but with mine it is a seal that has gone bad but I do keep an eye on the level of the fluid
I don't think it can be a major act to repair it since it can be done without removing the transmission. Mine don't leak until it sits for a few days but I want it fixed. Just want the correct seal or gasket on hand before I start.
 

Loadrunner

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Easy fix, get under the car, look, learn.

The "rooster's comb" shift quadrant shaft is O ringed to the case, so you undo/remove the linkage, drop the pan, drop rooster's comb being careful not to lose detent ball and spring. The kickdown shaft goes through the shift shaft so obviously there's an O ring there.

2 O rings you should source in advance.

Adding a pan drain is something to consider.

Use Fel Pro gaskets, follow directions.

Personally, I glue the gasket to the pan by letting sealer set up until gasket is firmly in place, and use no sealer at all between the gasket and the aluminum case.

This method allows for the pan to be removed in minutes without hassles as many times as you like and doesn't leak.

Us this same method on valve covers unless you want either leaks or removal hassles.
 
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Sixpactogo

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Easy fix, get under the car, look, learn.

The "rooster's comb" shift quadrant shaft is O ringed to the case, so you undo/remove the linkage, drop the pan, drop rooster's comb being careful not to lose detent ball and spring. The kickdown shaft goes through the shift shaft so obviously there's an O ring there.

2 O rings you should source in advance.

Adding a pan drain is something to consider.

Use Fel Pro gaskets, follow directions.

Personally, I glue the gasket to the pan by letting sealer set up until gasket is firmly in place, and use no sealer at all between the gasket and the aluminum case.

This method allows for the pan to be removed in minutes without hassles as many times as you like.

Us this same method on valve covers unless you want either leaks or removal hassles.
Thank you for that info! I planned on a new pan gasket and filter & fluid. Do you know if the two O rings are a standard size? If so, I have a standard and a metric O ring kit. I have a service manual and a parts book. The parts book makes reference to the seal on the kick down shaft but doesn't give a part number.
Anything else I should attend to while I'm in there? It has been working great for a lot of years but does seem to shift into 3rd a little sooner than it should even though the linkage is adjusted according to the book.
 

57fury440

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Which tranny does he have? He says cast iron 727. I think he is referring to the older torqueflites which are cast iron and different from 727s.
 

Loadrunner

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Oops, 1960, cable shift, cast iron case.

You need the appropriate FSM but I'm guessing the O rings will not be anything special. They hadn't even heard of metric back then.

I also have the O ring assortments, both Red and Blue and you look at them and tell me there's a difference between the O rings from box to box, the only real difference is the color of the box ;]

And at the same time, I would not trust an O ring from these assortments for this job, buy something of better quality than 1000 O rings for $20...

I'd try to shop with a transmission parts wholesaler/retailer for sensitive parts like these.


Mopar was well ahead of the curve on transmission sealing, using O rings, also by way of not using a vacuum modulator to set shift points like both Chevy and Ford, marching to the beat of their own - and much better - drummer.
 
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1970FuryConv

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My 60 Dart has developed a leak around the kick down lever. Anyone have experience with replacing the seal? Pretty sure I need to drop the pan and valve body to get at it. Is it a standard O ring or does it take a special seal.
Any tips on this operation would be appreciated.
@413 can probably help from experience with the 1960 cast iron trans
 

Sixpactogo

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Oops, 1960, cable shift, cast iron case.

You need the appropriate FSM but I'm guessing the O rings will not be anything special. They hadn't even hear of metric back then.

I also have the O ring assortments, both Red and Blue and you look at them and tell me there's a difference between the O rings from box to box, the only real difference is the color of the box ;]

And at the same time, I would not trust an O ring from these assortments for this job, buy something of better quality than 1000 O rings for $20...

I'd try to shop with a transmission parts wholesaler/retailer for sensitive parts like these.


Mopar was well ahead of the curve on transmission sealing, using O rings, also by way of not using a vacuum modulator to set shift points like both Chevy and Ford, marching to the beat of their own - and much better - drummer.
I have the factory service manual which shows the break-down but no part numbers. The parts book shows Part numbers and references the seal for the kick down lever but does not give a part number so I don't know if it is an oil seal or O ring. Guess I will find out when I open it up. I was hoping to have all the parts and gaskets before hand. There is a transmission shop locally that built my transmission back in the 80's but the owner is now gone along with everyone else that knows these old transmissions. I'm not sure I could get any leadership from them since they have probably never seen one. I may drive over there though and feel them out a bit.
 

1970FuryConv

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I have the factory service manual which shows the break-down but no part numbers. The parts book shows Part numbers and references the seal for the kick down lever but does not give a part number so I don't know if it is an oil seal or O ring. Guess I will find out when I open it up. I was hoping to have all the parts and gaskets before hand. There is a transmission shop locally that built my transmission back in the 80's but the owner is now gone along with everyone else that knows these old transmissions. I'm not sure I could get any leadership from them since they have probably never seen one. I may drive over there though and feel them out a bit.
I'd PM member 413. I'll bet he knows the answer from experience.
 

Loadrunner

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Looks like the cast iron TF is a whole different ball game, may even be easier to fix than the later linkage shifted trannies, as those actually take a pair of actual seals and there's a puller made to pull the seal/s.


Screen Shot 2022-10-13 at 8.34.15 AM.png
Screen Shot 2022-10-13 at 8.34.37 AM.png
 
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Sixpactogo

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Yeah I know they are way different than the later aluminum 727's. Mine is leaking at What your pic shows as "throttle lever".
The seal around that shaft is the culprit in my case. Are you saying there is a tool to pull that seal? I was thinking that seal has to go in from the inside. If it goes in from the top, I guess the transmission cross member would need to come out to allow enough room to access it. My service manual indicates it can be serviced in the vehicle but doesn't mention using a special tool or dropping the cross member or any procedure. That is why I was hoping for some leadership from someone that has dealt with this particular issue. I'm gonna check with my transmission shop to see if they can be of any help.
Thanks for yours by the way.
 

Loadrunner

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Yes, there are seal poppers or pullers, at least for the large later selector shaft seal.

This is not a big issue to fix.

If you have the ability to get under the car comfortably, loosen/remove the throttle lever and look under it - or look at pics of gutted transmissions online - IF Chrysler put the seal outside the case, all you have to do is pick the seal out, with a seal pick, carefully, you do not want to scratch either the shaft or in this case cast iron case, which is nice because aluminum is much easier to damage, remove seal, find appropriate "installer" tool, generally something like the appropriate deepwell drive socket to clear any shaft sticking out.

If the seal is trapped by the case and has to be removed from inside, you have to drain/pull the pan, and RR the seal from underneath.
 

Sixpactogo

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I have a gasket set for the 56-61 Cast iron 727 but there is no oil seal included that would fit that shaft. The kit has the front pump seal, Tail shaft seal, filler tube O ring, Shift cable O ring, Tail shaft gasket and Pan gasket. There is one small O ring that looks small enough for the kick down shaft so I will drop the pan and go from there. It seems like an O ring would be a cheap Charlie type of seal but that's probably why they are a typical place to leak. I did go to my local transmission shop but it was as I thought. No one there has ever seen one of them. Matter of fact, they wanted to argue the fact that Chrysler never made a Cast Iron 727. According to them, they were all aluminum. The cruising season is about over here in Wisconsin so I will be getting at this project real soon. Thanks for the help.
 

57fury440

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The cast iron torqueflite is not a 727. All 727 transmissions were aluminum and started in 1962. I've owned and raced cars with the cast iron units but they are not 727s.
 
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