TH350 Shift Shaft Seal

[Chief Brody]

I got the detent cable leak stopped, the dipstick tube leak stopped, the accumulator cover seal leak stopped....now I have one more.

The shift shaft seal...on the transmission....how easy or hard is that one? So close....yet so far....

 

[Chief Brody]

I can't find anything posted about changing the shift shaft seal. I went to NAPA and they had the seal and a special tool for removing it. No instructions or anything...maybe it becomes clear what you have to do when you tear into it.

 

[DeviousK5]

Take the manual lever off... remove the bolt from the special tool... screw teh body of the tool in while gently tapping in on it with a small hammer...keep turning the tool until you feel the threads bite into the seal...put the bolt into the tool, hold the tool with a wrence and screw then bolt in until the seal jumps out... they sell an installer but it is nothing more than a smapp piece of pipe with a cap on the end...so find a socket of proper size and press it in, making sure not to fold the lip of the seal outward...

Hope you can make sense of all that

 

[boz42]

Without the tool it is hard to get out with out dropping the pan & removing the shift linkage rod that runs through the seal. Installing it can be a challenge with the shift rod in place also. It can be done. The tool makes it easier. Or you can make one like devious said.

Kent Moore makes them but I don't know the part number. I am sure someone else makes them also. Someone could look at an ATSG manuel, It should give the tool number. I don't have one for the T-350.

 

[Chief Brody]

OK! Got it done!

I got the seal from NAPA for $5.49 and the seal removal / installer tool for about $6.00

I jacked up the truck and crawled under, here you can see the shift selector on the driver's side of the transmission:


I then removed the keeper pin from the shifter bracket and unbolted the bracket. I had to lightly tap and pry it loose. Here they are...need to be cleaned with Brake cleaner:

Then I took the seal removal tool and "seated" it straight with my fingers, pushing pretty hard, then tap on it with a hammer a few times until it "stuck" into the seal. You will know when it has done that because when you gently tug on the removal tool with just your thumb and index finger it won't fall out...it resists. I can't state enough how gently you need to do that. Then the bolt that comes with the tool screws in and seats and at that point you need to get a wrench to hold the tool still and a socket to turn the bolt....this eases the seal out:



Then I cleaned the whole area around the shift shaft and sprayed brake cleaner all over it.


Then I grabbed the new seal and wet it down with ATF...:

Then pushed the seal on with only my fingers untill it was straight and barely stuck on...you have to push pretty hard to get the little seal on...then I took the installer tool and lightly tapped it in:

Then I tapped in all the way in until it stopped and seated...it is such a tight fit that you can see the seal left paint on the cylinder.

After that just re-install your bracket, bolt and keeper pin.

 

[Chief Brody]

cont..

 

[Chief Brody]

Don't make the mistake that I did....I wasn't watching when I took the shifter lever off and didn't see that the other end rests in a "socket"...I installed it without putting the other end in that socket and I drove off to the end of the driveway (it went into drive) and when I stopped and it wouldn't change gears...the shifter was stuck.

I got under there and had to take the keeper pin back out and put the other end into the "socket" and put the keeper pin back in and voilla...

So far no leaks in the drip pan...I drove it around and parked it and put a clean drip pan underneath and nothing yet!!!!

 

[Chief Brody]

Is it obvious that I don't know how to insert a photo after a sentence?

 

[Chief Brody]

I still can't figure out why they didn't design this with some kind of cover over the shaft cylinder....it's wide open behind the shifter bracket...anything would be better than nothing...a washer...something...

 

[magik235]

So far no leaks in the drip pan.

Excellent