The crankshaft seal has gone and we think it is getting oil on the clutch plates, how difficult is this to replace or is it an engine out job?

Becky,

Not good.....I take it you are sure its the clutch.. You did mention there wasn't much life in him. In his clutch I mean.
Given what you did for his final drive I think you might be able to do it with some help. My bike buddy over here does them but he has decided to give up. I asked him to take mine in the winter and do all the splines and check it over but he wouldn't.
88KE did that job on his LTY just before we went to France.

we managed to change the shaft really quickly because we have done it before! and yeah been to my mechanic and hes diagnosed it. not sure if the clutch has actually gone, we think it may be due to the leaking oil getting onto the plates. if we can replace the seal without full dismantling it should be ok, is it possible to do without taking everything out?

It's possible to do it without stripping the entire bike down but you'll need to make a support box for the engine at the very least. This might help:

https://www.youtube.com/watch?v=q48EptqVzB4
https://www.youtube.com/watch?v=HZJdZ1HszkA (one of five).

Having never worked on one but looking at the Haynes manual the crankshaft seal is installed from the outside so doesn't look to bad as long as its leaking due to age or use only and the crank and shaft against seal is good.

Saying that. I really must stress never been there or done that.

ah if its installed from the outside it may be do able. not too expensive to buy and hes on his way out, worth a try! need to save him!

Eesy peesy

I had never done a rear seal, but had been down almost that far into the bike.

Took it to RT's place where a crowd had gathered to watch me stuff it up get it right first time.
Got it right first time.

Pretty well all five said in unison "oh, is that it?"

There are only 2 parts that require some sort of ... something I can't think of.

Taking off the seat and rear cowl /mudguard (and remembering how it goes back together) and replacing the gearbox.
Take photos of the cowl if you have not done it before. Lots of screws n stuff.
Gearbox has two locating pins that can be a bugger to get right, but no reason it should not go back together if you swear enough. Two people make it easier. Just blame each other.

Allow a day. Actually took almost as long to put back the seat/ pretty bits than it did to get the seal in, gearbox fitted, wheel on, foot pegs on.
Have a go.

THIS WONT HELP AT ALL

ha ha sounds just vague enough to work! might be a job for me and snod when hes up here

Becky wrote:ha ha sounds just vague enough to work! might be a job for me and snod when hes up her

If you remove the cylinder head and piston 3 someone with small hands could reach in and slip a new seal on while you pull the crank forward.
You will need cut a small hole at the front to slide crank forward which you can replace with JB weld after.
This would mean only limited parts removal. Spray wet and forget in before fitting the new seal. That should remove any built up oil on the clutch.

Tolls required.

Hi Becky,

This is the third time I have tried to reply, but the post hasn't appeared!

In the helpful 'This wont help at all' link, the first photo shows what needs to be replaced while you are in that far.

It's not a technically difficult job, but there are some big lumps to manhandle (womanhandle?  ) about. A couple of gearbox support pins can be made from some M8 threaded bar. These will help when removing and installing the gearbox, and prevent it from resting on the input shaft. I also use a trolley jack to support the box during alignment and it makes it easier to wheel it out/in. You could remove everything from the gearbox backwards as one lump to save disturbing too much, but it's heavy and unwieldy. 

BMW changed the dimensions of their seal insertion tool (#11-1-630) so that a new seal would sit 0.5mm further out that previously. (IIRC this was for the new teflon lipped seal), but you could just measure where the existing seal sits and gauge how far in to press the new one from that.

Mike

It's not a difficult job. It'll take some time, bit depending on how experienced you are and the tools you have, but if you work 'organised' it's very doable. There are some descriptions on the hub (how good is your German??) and some good YouTube movies as well. And we're here - what can go wrong? Have a sawhorse to support the back end of the bike or ty it up somehow.

Is it leaking engine oil or gearbox oil through the leak hole?

we think its engine oil

Have a good sniff of the oil. Gearbox oil has a distinctive aroma very different to engine oil.

Mike