TH400 question
Thread Starter
Heel & Toe
Joined: Sep 2006
Posts: 18
Likes: 0
From: Sydney
TH400 question
Hi guys,
has anyone replaced the selector shaft seal with the tranny in the car. It seems there is not much room there on our cars and don't want to start something I can't finish. If so what technique did you use?
has anyone replaced the selector shaft seal with the tranny in the car. It seems there is not much room there on our cars and don't want to start something I can't finish. If so what technique did you use?
Limping across the line
Joined: Oct 2002
Posts: 5,299
Likes: 109
From: Peoria Az
Yes I have but its best to use the special tool for removing the seal. If you nick the selector shaft it will leak continuously.Then you'll have to replace the shaft
Ask me how I know
Its tool number 84025
http://www.performancetool.com
Ask me how I know
Its tool number 84025
http://www.performancetool.com
Last edited by AzMotorhead; Sep 15, 2007 at 10:36 AM.
Intermediate
Joined: May 2005
Posts: 34
Likes: 0
From: Bay Point, CA
I have a '72 454 with a TH400. I had to replace the seal several years ago. I read the factory manual and to replace the seal/inspect the shaft itself for corrosion (my problem) or burrs on the shaft where the seal seated I decided to remove the shaft. This is important because if the shaft is the problem the leak will reoccur if you just replace the seal.
There was no room for any tool between the tranny and the tunnel. To remove the shaft, drain fluid, drop the pan, disconnect the shaft linkage from inside (easy to do with the factory manual instructions), and slide the shaft out. Use a pick/jhook to remove the seal (easy with shaft out), inspect/clean shaft as necesarry, install new seal, install shaft/linkage, pan, tranny fluid, and your good to go.
Now for the trick: you cannot slide the shaft all the way out because it will hit the tranny tunnel. You may be able to lower the tranny enough to get the shaft out by disconnecting the tranny cross member, but I decided to cut a small hole in the tunnel just opposite the shaft. The shaft slid out of the tranny and into the hole far enough so I was able to remove it from the transmission.
I hope this helps. Good luck!
There was no room for any tool between the tranny and the tunnel. To remove the shaft, drain fluid, drop the pan, disconnect the shaft linkage from inside (easy to do with the factory manual instructions), and slide the shaft out. Use a pick/jhook to remove the seal (easy with shaft out), inspect/clean shaft as necesarry, install new seal, install shaft/linkage, pan, tranny fluid, and your good to go.
Now for the trick: you cannot slide the shaft all the way out because it will hit the tranny tunnel. You may be able to lower the tranny enough to get the shaft out by disconnecting the tranny cross member, but I decided to cut a small hole in the tunnel just opposite the shaft. The shaft slid out of the tranny and into the hole far enough so I was able to remove it from the transmission.
I hope this helps. Good luck!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Once you get the shaft out, you can use a screwdriver to pop the seal out...lay the s/d across the seal bore [in the housing] with the flat blade inside and under the seal casing. Then just pop down on the handle of the driver with the palm of your hand. It doesn't take much. When installing the new one, just make sure you don't have it cocked in the bore. It's easiest just to use a flat piece of metal to pound it flush with the bore surface once you have it started in the bore and fairly straight.
