Shift Shaft Seal in 915 Removal

[arbita1]

How to you remove and replace the rubber seal in the end cap of a 915 transmission. It is where the shift rod goes through.

I've been trying to pry it out with a screwdriver. But it's just breaking apart and sticking in the hole.

[Peter Zimmermann]

Matt: I started with a fairly narrow, flat-bladed screwdriver (about a 14" long shaft + handle) and ground the tip until it formed a shallow hook. It took many trips to the bench grinder until the tip was just right, and I could get a hold of a meaty part of the seal and lever it out without scarring the aluminum around the outside of the seal.

[FenderBender]

I have to do this as well. I thought I read in a thread about putting a screw through it for pulling it out.

[fumanchu]

just did mine and it came out easy with a small flathead and a hooked awl. Putting in the new one is more critical.

[FPB111]

I heated the tip of a short screwdriver and bent it to a 90 deg angle to use as a hook against the inner corner of the seal. Once you get it into the seal you can use hammer persuasion against visegrips clamped to the screwdriver shaft if need be.

Also if you have acces to a lathe or drill press you can drill a hole in a piece of plastic or wood dowel for snug fit over the shift shaft and use it as a guide tool to push the seal in square. I used a piece of wood against the firewall to back up a prybar that was pushing against the dowel that was held square against the seal by the snug fit around the shaft. It worked great.

[arbita1]

Would one of these work?

[BK911]

Originally Posted by FenderBender

I have to do this as well. I thought I read in a thread about putting a screw through it for pulling it out.

That's the way I do it. A small screw and a slide hammer works every time.

[coollx]

Matt,

I found the biggest problem with getting the seal out is that it has a metal jacket the rubber seal portion is bonded to. I used a small sharp round tool to drive down on the outside of the seal to push the metal jacket inward. Then you can use a chisel or small tipped screwdriver to tap it further toward the center of the seal. If you are careful you can do it without scaring the casting. Once I pushed the jacket in far enough, I was able to grab it with a pair of needle nose vice grips and pull it right out. Hope this helps.

[Peter Zimmermann]

Originally Posted by arbita1

Would one of these work?

No, there isn't room for the tool. FYI: That's the tool that I use to remove main shaft seals from pre-'72 transmissions - works brilliant!

I have replaced seals where someone else has damaged the aluminum, both around the seal, and at the very tip of the seal recess. I use a tool that I know as a burr-quick (a small handle with an angled, metal cutting blade) to shave the tip and remove a small amount of damaged metal.

To deal with scars around the OD of the seal, I use crocus cloth to smooth them off as much as possible, then put a thin coat of Curil T on the outside of the seal before I push it home. Works every time - I've never had one leak.

One more trick - while you're cleaning the area always check the area around the hole where the pin screw that holds the coupler goes. That surface can often have a raised sliver of metal that can cut the new seal as you slide it on - that's bad!

[arbita1]

I was able to remove it with a flat head screwdriver.

Now I drove in the new one, but I'm not sure how far to drive it in. The old one looked like the rubber was close to the top of the hole. The new one looks like it will recess more into the hole than old one did...I think. (I should have looked at it more carefully before I removed the old one.)

Should I keep driving it in all the way? The shop manual say "drive in until fully seated".

[Johnb911]

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[arbita1]

Originally Posted by arbita1

I was able to remove it with a flat head screwdriver.

Now I drove in the new one, but I'm not sure how far to drive it in. The old one looked like the rubber was close to the top of the hole. The new one looks like it will recess more into the hole than old one did...I think. (I should have looked at it more carefully before I removed the old one.)

Should I keep driving it in all the way? The shop manual say "drive in until fully seated".

Never mind. I drove it in too far. Now I need a new seal.

[SpeedracerIndy]

Originally Posted by arbita1

Never mind. I drove it in too far. Now I need a new seal.

I did the exact same thing. This is the one job that I actually took to a pro when I reinstalled it.

When I rebuilt my 915 (an '81), I was using a Bently manual for a Carrera. What I didn't realize, and my local 915 rebuilding later told me, was that the install depth of the seal is different throughout the years. He had to fish out the seal from the tranny and reinstall it correctly. It has been perfect since.

Boy did it make a mess in the car though. I had it installed wrong for about 2 years. I couldn't figure out why my transmission oil slowly went down, but wasn't leaking on the ground. When I opened up the access panel behind the seats, I saw a nice big puddle of Swepco.

[arbita1]

I didn't even see anything in the bentley manuals about the seals.

[74threeliter]

If the shift shaft seal was driven 1/2" farther in than the end of the nose, would that be bad? The old seal's end met with the nose end. I drove the new one just a tad farther in.

[DRACO A5OG]

It could leak, keep an eye in that area for a leak under the car after a drive.

[cmcfaul]

I know this is an old post but getting the old seal out while the trans is installed in the car looks to be very difficult.

Has anyone simply installed a new seal on top of the old seal. It looks like there is plenty of room to push the old seal further in.

Chris