Transmission Seal Replacement


This job is not too complicated, but there are a few "sticking points" that can really mess you up. There are also some things that are best done "while you're in there."

The exhaust definitely has to come out. The sticking point here is the nuts that hold the cat to the manifold may be really hard to break free and they are a bit difficult to reach. I used a combination of box-end wrenches and a 2ft long socket extension with universal joint to loosen. You will need new gaskets for the manifold to downpipe connection and it may be a good plan to have spare nuts and studs on hand (they are special copper nuts).

You then need to remove all the heatshields covering the driveshaft - pretty simple. Watch which bolt goes where.

You can then remove the driveshaft. Undo it from the transmission flange and unbolt the center bearing so you can move the shaft around. You should only use new locking nuts on the flex disc on reassembly.

This is an excellent time to replace your flex disc (AKA "Guibo", or "rubber donut") and center bearing, if they are in the least bit suspect. Check that the driveshaft sliding joint is OK and that the collar nut is tight (mine was loose and caused a bad rattling noise and clunk).

I would also take this chance to replace any worn shift linkage bushings. The coupling that goes on the transmission selector shaft is usually the major cause of shifter slop - you can **only** get to it when the driveshaft is out and even then...

Also, plan on replacing the little selector shaft seal. This can actually cause more oil leakage than the main output seal. They can be a bugger to remove. I had to use every small pick-like tool in my arsenal and it took me an hour. Ideally, I think a crochet hook/knitting needle would have worked best. You have to be very careful not to scratch the aluminum housing or the selector shaft - otherwise, it would only take a minute! Get a couple of these seals, they are cheap. It is easy to bugger them up on reassembly and then have the car undriveable while you wait for the stupid little $2 part to come in... Ask me how I know!

To get the tranny output flange off, you'll need a special "thin-wall" 30mm deep socket (another sticking point if not forewarned). I made my own using a generic 30mm deep impact-socket and grinding down the first inch or so of the OD. With the shaft nut off, you will likely need a puller to remove the flange from the tranny. My output flange had a "balancer" built onto it that made use of the 2-jaw puller I had rather awkward. A 4" 3-jaw puller would be best. Make sure to follow the Bentley manual instructions on reassembly and be sure to properly torque the big output flange nut. I used a bit of blue Loc-Tite on it as well.



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