727 transmission leak

[66chargertoy]

Almost have the car on the road with a few minor details to take care of, when just yesterday noticed a large oil spill underneath just below the transmission. Cleaned up everything where I suspected the leak came from, and noticed that it had a constant drip coming from around the shifter linkage. Now I'm no expert in this area, but I guess there should be a seal somewhere around the linkage in the trany itself. Question here is can I take that linkage apart and change the seal without having to remove the transmission

Denis

[lisiecki1]

you can change the seal without removing the trans, but you will more than likely have to drop the valve body....but that isn't too hard.....just don't let the balls fall out/get lost.

[Bob]

Here is the results on the same leak I had on my 727. This is cut and pasted from the 3rd gen site.

Took about 30 minutes to get the old seal out with the transmission still in the car.
Removed the transmissioon mount, lowered the rear of the tranny. This will give enough room to play around. Disconected the speedo cable, rear trans line, and linkages.
Removed the 2 shift/kickdown arms.
Made a semi special tool, heated a long skinny 6" flat tip screwdiver bent to a 45 degree angle.
Pryed out old seal.
Remember to have the new seal ready to go in. The trans fluid ran into the drip pan since yeaterday. About 2 quarts.
Today I will stop by NAPA and pick up the seal. 6 bucks.
I will use a socket and tap the new seal into place.
It's a good thing I had a spare tranny in the garage to practice on.
So, it is possible to change the seal with the tranny in the car.
There is actually 2 seals. There is a small rubber one that goes over the kickdown rod that goes up through the shift select shaft. This one was not leaking. I used a mirror and observed the shift shaft seal for an hour and sure enough that is where the leak was.
Bob

While you have the new seal in your hand, find a socket that is exactly the same size. I used a very small hammer with a handle about 3/4 (2.5 cm) in diameter and just tapped it in. Nice and flush and not crooked. With the transmission mount taken out there is plenty of room. If I remember right, your hands are much smaller than mine.

It was easy installing the seal. Place a socket over it, use a small hammer and tap it right into place. I checked this morning after topping off the fluid last evening and not one little drop. Saved a lot of time and hassle by doing it this way. I did use your part number because the auto parts stores could not find it useing there questionable search tools

The transmission in the pic is a test transmission.

I found a drip. It's comming the top seal of the kick down shaft. No problem, I have a spare. Same deal, will do it with the tranny in the car.

[66chargertoy]

Perfect !!! Thanks Bob for the info You wount' happen to have the parts number for that seal. If not, don't worry, I'll get my parts gurou to look it up.

Denis

[Bob]

Perfect !!! Thanks Bob for the info You wount' happen to have the parts number for that seal. If not, don't worry, I'll get my parts gurou to look it up.

Denis

Denis,
National and Timken use part # 7188S & 8609. ATP uses 4505098. Your local auto parts can cross referance these numbers to there part number. I got mine from NAPA.

National Oil Seals part # 8609
Part Number  8609
Shaft Size  0.812
Housing Bore  1.25
Outer Diameter  1.254
Width  0.254
Lip Material  Nitrile
Series  8000 
OE Number 8120839
OEManufacturer AMC
OE Number 8128797
OEManufacturer AMC
OE Number 2466842
OEManufacturer CHRYSLER
OE Number 3578447
OEManufacturer CHRYSLER
OE Number 3878447
OEManufacturer CHRYSLER
OE Number 4412836
OEManufacturer CHRYSLER
OE Number 4505098
OEManufacturer CHRYSLER


  Timken 7188S Seal
(Timken - 7188S, B000WFT2J8)

Price Range: $3.85 - $4.44 from 2 Sellers

Description: TIMKEN

http://www.rockauto.com/catalog/x,carcode,1079614,parttype,8648,a,www.google.com%20Search%20for%20Transmission-Automatic%20Selector%20Shaft%20Seal%20ATP

[66chargertoy]

Thanks

Denis

[Bob]

Thanks

Denis

Your welcome Dennis. The only thing I would do differently is drain the fluid first or you will have to be quick to do the switch.

[AKcharger]

I need to do the same thing but I needed to pull my valve body out anyway, is it easier with it out or do you still need to  lower the back of the tranny??

[John_Kunkel]

One problem with using a homemade tool to remove the seal by prying it out is you risk scarring the shaft. Once that's done, no seal will hold.

[Bob]

I need to do the same thing but I needed to pull my valve body out anyway, is it easier with it out or do you still need to  lower the back of the tranny??

I don't think you can get at it without lowering the transmission. John has a good point about scarring the shaft.

[AKcharger]

My way worked fine 

When removeing the Valve body the seal is completly exposed, just tap it out, the shaft is part of the valve body so it's not there.  That seal was my problem used to leak like crazy, now nice and dry 

[Nacho-RT74]

I made a instalation tool for the seal. BIG washers, bolt and nut. Of course, valve body out

[AKcharger]

I made a instalation tool for the seal. BIG washers, bolt and nut. Of course, valve body out

Smart!  I used a socket and hammer...but it worked!