Input shaft Oil Seal Replacement

[Kookaburra]

I now have the gearbox out of my 1985 R65 (thanks Rob for the excellent how to do it in the technical section) and I am now attempting to remove and replace the oil seal at the spline end which has been leaking badly. The old seal is hard and the remains are solidly stuck between the housing and some sort of shim/washer. I can see the wire 'o ring'  which was originally in the seal has dropped on to the bearings. Clymers diagrams are unclear as to the set up of all this .
I have been carefully cutting and picking away the old rubber but it's all still very stuck and I can only get down so far.
  I would appreciate any advice on how to get the seal /shim out without damaging the spline or housing and the correct way to install the new seal.

[Tony Smith]

  I would appreciate any advice on how to get the seal /shim out without damaging the spline or housing and the correct way to install the new seal.

Drill a couple of small holes in face of the seal - just enough to break through and no further. Then run self tapping screws part way into the holes you made - then use lever of your choice to lever the seal out using the screw heads as the anchor for your lever. A pair of forceps then comes in handy to dig out the spring if it has parted company from the seal. If you know a surgeon or a theatre nurse they are a good source of supply for forceps and the like - believe it or not such finely crafted pieces of surgical stainless steel are approved for but a single use, and after that use they are junk. Scalpels are a good item to collect from the same source.

Anyway to fit the new seal, find a piece of pipe that is just fractionally smaller than the seal and tap it in, after greasing the inside of the seal lips and a very light smear on the outside (clean the hole it goes into very carefully first of course). There are of course adjustable seal drivers you can buy to do this job, but they cost money and if you had money to buy seal drivers you would not be riding a nearly 30 year old motorbike.

[georgesgiralt]

Hello !
In screwing a couple of wood screws in the old join, you can get purchase for a pair of pliers. These are normally made of a steel reinforcing part covered with rubber so the screws will have "something to bite in".
Then to install the new one, you oil it a little and push it in with a properly sized socket the same size of the rubber. When it is flush on the housing it is done.
Put some electrical tape on the input shaft splines otherwise you will mar the very delicate lip of the seal. Not too much tape otherwise you'll distort too much the lip...

[Kookaburra]

Thanks Tony and Georges for the wise advice.

I was having one of those - don't do anything until you know what you are doing moments. Now all sorted with confidence. The extracted seal was seriously rusty and totally destroyed. No wonder there was such a bad leak.

I love my forceps and used a handy large socket to push the oiled up seal in.

Splines are in top shape so I'll grease up and reassemble with a new neutral switch (which was also leaking)  tomorrow.

This is such an awesome confidence building site.

Maintenance- it's all about peace of mind.

[montmil]

The seals can often be sourced from a local bearing supply house. The size of the seal will be marked the the seal's face. Or, if it's buggered up by removal, several BMW parts fiche will provide the seal dimensions.

Might be less expensive than a dealership or ordering out.