Th400 shift shaft seal replacement

[first64riv]

Hey guys,

Has anyone here replaced their shift shafts seal?  I plan to buy the tool from NAPA but wanted to make sure the seal is an easy DIY.

 

Thank you.

Chris

[telriv]

Chris,

 

   No problem using the tool. Makes the job quick & simple.  I've done hundreds with & without the tool. BUT not on your '64 Riv. The shift shaft  part is welded to the shaft unlike the '65 & newer which are held on with a 9/16ths. nut. You will need to drop the pan & dis-assemble from the inside to pull the shaft out of the case. Unless someone replaced the shaft with a '65 & up shaft during the course of a re-build. You can easily tell if it's been replaced as there will be a nut holding the shift part on.

 

 

Tom T.

 

 

[first64riv]

On 8/12/2018 at 9:38 AM, telriv said:

Chris,

 

   No problem using the tool. Makes the job quick & simple.  I've done hundreds with & without the tool. BUT not on your '64 Riv. The shift shaft  part is welded to the shaft unlike the '65 & newer which are held on with a 9/16ths. nut. You will need to drop the pan & dis-assemble from the inside to pull the shaft out of the case. Unless someone replaced the shaft with a '65 & up shaft during the course of a re-build. You can easily tell if it's been replaced as there will be a nut holding the shift part on.

 

 

Tom T.

 

 

Tom,

 

I wanted to revisit this and ask, since the shift shaft is welded is there any grinding involved in the process during replacement? 

 

Thank you

Chris

[telriv]

No Chris there is not.

[first64riv]

UPDATE:  I finally got around to doing the shift shaft seal replacement.  The job is straight forward.  I did not use any special tools, just a large bolt the same diameter as the inner diameter of the seal.  The old seal was the metal style outer with a rubber inner.  I used the National PN 8792s seal.

 

Tips: the seal will not install with just finger strength.  You will need to use something to punch it in.  In my case, I used the head of an over the oven microwave bolt to punch it in with a ball peen hammer.  Also, remember the orientation of the gear a shift pawl.  I'd recommend taking a picture of it.  I did not do this and I was worried as all hell when I reinstalled.  Just the thought of screwing it up and having to redo it all worried me.  Fortunately it went back together fine.

 

The transmission pan gasket, the bane of my existence,  is finally sealed using a Felpro gasket.  It looks like the fiber style.  I also ditched my previous stamped oil pan for an AC Delco chrome pan.  I'm not sure what helped to aid in stopping the leak but I also installed everything completely dry.

 

I hope this info helps someone in the future.  If there are any questions, I am happy to answer.  If I can do it, so can you!

 

Thank you,

Chris

Edited April 19, 2020 by first64riv
Spelling (see edit history)

[telriv]

Chris,

 

    Glad everything worked out for you.

 

Tom T.