Trans shift shaft seal.

Anonymous · Post by **Anonymous** » Mon Jan 31, 05 2:48 pm

Any tips on replacing the shift shaft seal? Seems like this is the location of my leak.
I understand that torque converter shaft seal allows fluid to drain back into the transmission after the car is shut off if it`s poor. The fluid in the transmission case then begins to rise, and eventually overflows out through some of the places where the seals have dried out.
Is this the initial cause of my leak, or do I need to replace convertor shaft seal as well?

Dave-R · Post by **Dave-R** » Mon Jan 31, 05 3:44 pm

Just replace the seal that leaks to the outside mate.

Is this the gear selector shaft seal you are on about? The little vertical shaft that seals just above the pan gasket on the drivers side?

It is a fiddle to do. You need to get all the lines and linkages out of the way. You might be able to do it without dropping the pan and valve body but I found on my Challenger I needed to.

With the valve body out it is easy to get the old seal out. Getting the new one in is the tricky bit. MAKE SURE IT IS TAPPED IN SQUARE. If it goes in lop sided it will not straighten out without knacking. I might be able to find a spare one as Duncan was kind enough to send me a couple when I made a mess of mine.

No way could i get a hammer or anything over the seal to tap it home. I used a little scrap bit of 1/4 plate i have. I could just get it in and it was just heavy enough to tap it home.

Anonymous · Post by **Anonymous** » Tue Feb 01, 05 8:48 am

yeah, it`s the top selector seal, that`s nigh on impossible to get at. Got a crick in me neck just trying to look at it

I wondered how to get it out without dropping the pan - some notes on the Imperial pages suggest using a special tool or if not available drop the pan and tap out from the bottom with a drift and pull the new one down using a half inch nut and bolt with washers. If I have to drop the pan I may as well think about a shift kit at the same time, while it`s apart. Any suggestions on a kit?

Dave-R · Post by **Dave-R** » Tue Feb 01, 05 10:03 am

neil wrote:pull the new one down using a half inch nut and bolt with washers.

Mmmm. I never thought of that! Certainly knocking the seal out when the valve body is out is easy.

Why do you want to modify the valve body? Seems a bit drastic for a stock 318?

Anonymous · Post by **Anonymous** » Tue Feb 01, 05 10:36 am

huh, my little 318 not worthy eh?

Just thought it would firm up the shift a little. Besides, it might not stay stock forever you know

Dave-R · Post by **Dave-R** » Tue Feb 01, 05 10:50 am

OK then. If you really want to firm it up it is possible without a shift kit.

Anonymous · Post by **Anonymous** » Tue Feb 01, 05 12:44 pm

Tell me more

Dave-R · Post by **Dave-R** » Tue Feb 01, 05 1:44 pm

I will have to dig out the info but I am worried it might make it too firm for you. You don't want a big BANG every time it changes gear pulling away slowly in traffic.

Dave-R · Post by **Dave-R** » Wed Feb 02, 05 8:05 pm

Sorry mate. I looked into my stuff and the info i have is just for the 727. I don't know if the separator plate in the 904 is the same or not but I suspect not. If by any chance it is the same I can show you how to firm up the shifts without any expense at all.

I don't know if just loosing the accumulator spring will help or not? Dunc? Blue?

Blue · Post by **Blue** » Wed Feb 02, 05 8:27 pm

Yes, removing the accumulator spring will firm things up a bit, 727 and 904 valve bodies are the same, so any valve body mods for a 727 are relevent.

Dave-R · Post by **Dave-R** » Wed Feb 02, 05 9:22 pm

Cool! Thanks Blue.

In that case....

Remove the valve body (don't forget to remove the back up light/neutral switch first) and you will find the accumulator spring will remove itself. Fig 1.

Dave-R · Post by **Dave-R** » Wed Feb 02, 05 9:28 pm

Make yourself a 3/8 x 2.75" bit of steel rod and put that under the piston (#2 in photo above). This disables the accumulator piston.

Now take the valve body and place it down with the screw heads facing you. Remove the screws holding it together and lift the cover and the seperator plate. Don't loose any of the steel balls left in the main part of the valve body. If any jump out here is where they go.

1 = 5 x 1/4" balls.
2 = 1 x 11/32" ball.
3 = 1 x 3/8" ball (not all trans have this).

Dave-R · Post by **Dave-R** » Wed Feb 02, 05 9:30 pm

Now take the seperator plate and compare it to the photo below. Drill out the five holes marked with an X to 3/16". Deburr the holes after drilling.

Dave-R · Post by **Dave-R** » Wed Feb 02, 05 9:34 pm

All the above from a 1989 copy of Hot Rod.

Anonymous · Post by **Anonymous** » Wed Feb 02, 05 10:09 pm

And if you come out with a crystel you get an extra 15 seconds of time in the dome!