727 Trans Leak - Selector Shaft Seal?
 

The guy I bought my car off of (1967 Plymouth Fury Sport) said that the trans was leaking fluid. He gave me the seal to fix it (Part#03878447) but he didn't tell me what the seal went to. After some searching I found that it can either be the selector shaft seal or the kickdown seal. What is the best way to replace these seals? I plan on replacing the pan gasket and filters and I'd like to replace this seal while I'm at it. Any help would be appreciated. I'm assuming it's on the left side of the trans.

If you have the pan off I would drop out the valve body after removing the kick down lever and gear selecter lever. Push the seal out from below. Clean the exterior of the seal area as best you can. When I did this a number of times I would lower the rear cross member , then lower the tail shaft of the trans as far as you can with out damaging the dist. if its a small block,fan etc. Then I would push the seal in place after a final cleaning of the area. I used a socket and c clamp. Then put everything back in . If you have any questions just ask.

Chuck

What do you have to do to drop out the valve body? Can you replace the seal without having to do this?

You can but you will have to get the trans tail shaft as low as possible with out wrecking stuff in the engine bay. Then clean the seal area after removing the levers. Now you take a small screwdriver and pry the seal out . Be very careful not to damage the case or shaft of the valve body. After its out and the area is all cleaned up. Take the new seal and put a light coat of grease on the seal area. and a little sealant on the external part of the seal . Now carefully tap the seal into place with a deep well socket the only contacts the the outer top edge of the seal. I dont remember what size but make sure it clears the sharts also. You might want to check for a piece od short pipe rather than a socket. Then you ready to put it all back in place.

Chuck

I looked in my service manual and could not find the "trans tail shaft" so I'm not sure what "You can but you will have to get the trans tail shaft as low as possible with out wrecking stuff in the engine bay." means. I appologize for ignorance. This is the first I've ever worked on a transmissions (besides changing the fluid, gasket, fiter..etc). I really appreciate the information you have provided me.

Not a problem
The tail shaft is the part of the trans that the drive shaft is slid into. becareful not to damage the spedo cable. You will be removing 2 bolts that are vertical in to the tail housing and then the 4 that are horz. in the cross member support. Becareful when you lower or raise the trans. that the drive shaft dosnt pull out and hurt you ,you might want to remove it so there is no chance of that happening. Be very careful you have the car positioned in a safe way . Jack stands ,floor hoist. I would feel bad if you got hurt and I didnt know you were not as well versed in this stuff as I some times take for granted. Keep asking all the questions you need . There are no dumb questions.

Chuck

I believe replacing that seal can be done in car, but if you're going to go through the work of pulling the driveline out and pulling off the trans crossmember, just pull the trans out.

You'll save you're safe alot of hassle, headaches and time.

Pull the trans pan off, and youll see the valvebody with the filter, filter should have two 7/16ths or 9/16th bolts. I cant remember. Then youll see the valvebody, about 8 bolts hold it in, easy to pull out.

Get yourself a service manual.

Selector shaft seal
 

You need to use the old trick we used in the old days. After you drop the valve body you drive the old seal out from the bottom. After cleaning the groove that the seal fits in put a bolt as big as you can fit through the seal with a large flat washer under the head of it through the middle of the seal. Then put another flat washer on the bolt and screw a nut from the bottom side and slowly tighten so the seal will be pressed into the trans housing. That's how we did it back in the day so we didn't have to drop the trans down. Use caution when reinstalling the valve body as the park pawl rod must fit back into it's hole for the valve body to line back up properly.

clever idea

I'm not sure if it is the same on your car but below are the instructions for replacing the gear selector grommet. My tranny is a '65 727 cable shift. Other spots for leaks are the Parking Lock Cable (below as well) and the neutral safety switch.

Gear Selector Cable Seal:
http://i28.photobucket.com/albums/c2...s/Tranny-1.jpg

Parking Lock Cable Seal:
http://i28.photobucket.com/albums/c2...s/Tranny-2.jpg