Turbo 400 selector shaft seal questions
 

So I bought the special tool to remove/replace the selector shaft seal on my T400...went to slide the tool over the shaft just now, and it will not go on. I do not have another trans to try it on to see if the tool is the wrong size. Does the T400 have a larger selector shaft than a T350? TIA

Re: Turbo 400 selector shaft seal questions
 

Early TH400's ('64-'67) have a O-ring on the shift shaft & requires removal of the shaft to change the O-ring.

If yours is a '68 & up.....That tool will work.

Re: Turbo 400 selector shaft seal questions
 

sounds like I may have an earlier one in the truck then, because the tool isn't even close to fitting over the selector shaft...would you happen to have a good reference guide for replacing the seal with shaft removal? Thanks for the info

Re: Turbo 400 selector shaft seal questions
 

I know this is an old thread but I thought I would post my recent experience in case it can help someone else when they search on this topic.

I too had problems with the seal removal tool not fitting over my shift shaft (1970 TH400). After reading some reviews of the various tools available online, it seems this is a common problem. Either there is some variance in the shaft OD or the tool ID. I was able to take a few thousandths off the ID of the tool with my Dremel sanding wheel and then it worked fine.

The tool I bought was Evercraft brand from NAPA. There are several others available on Amazon but be careful as some reviews indicated tools breaking off at the threads inside the shift shaft opening.

I had to press fairly hard on the tool while threading it into the seal, to get it to grab. I was being careful the first couple of tries and it didn't grab because I wasn't pressing hard enough.

New seal went in fine with the installation tool (which interestingly fit over the shaft fine).

Re: Turbo 400 selector shaft seal questions
 

The main reason these tools "wont fit" over the shaft is burring of the slot edges causing an enlargement of the shaft area where the shift lever goes on.

I use a small hand held stone to remove the edge lips and make sure the shaft feels smooth...

Hint...I usually add a small O ring around the shaft under the seal.

:chevy::chevy::chevy: