Gearbox input seal

[Flying banana]

I am considering changing me clutch myself, as it on its way out. However, I strongly suspect that either the crankshaft seal or the gearbox seal have failed. I have no problem with what to do with the crankshaft seal, as it can be relatively simply replaced.
Can anyone tell me if the gearbox seal is as simply replaced? Or does the box have to be dismantled to some degree to change said seal?
Also, does anyone have a copy of the CD rom workshop manual that I could maybe beg/steal/borrow, etc please?

Any help most gratefull recieved.

Cheers chaps

Phil

 

[Flying banana]

So, no one knows, then?

As it 'appens, I have found what I am looking for as far as the BMW manual goes, so thats not a problem. However, if anyone has experience of changing the gearbox seal, I think I may have worked it out, but would appreciate any tips.

Cheers

 

[Arbreacames]

Yours is a 1150, right? If so, you're in good shape because the seals can be replaced without opening the gearbox, which is not the case with the 1100. I have a few suggestions.
1) The problematic seal that contaminates the clutch is ususally the rear input shaft seal, which is actually on the back of the gearbox, just behind the clutch slave cylinder. Gear oil travels along the clutch rod across the entire gearbox.
2) Make sure you take advantage of the opened clutch to lubricate your clutch splined shaft with Honda Moly 60 paste.
3) I have the impression that before a main crank seal fails there should be a lot of blow-by oil coming from the drain under airbox. The reason is that the main seal is actually two seals that are part of the crankcase ventilation system. If you need to know more, I will send you the link.
4) Before removing ANY seal, make sure that you measure its depth. I think that none of the engine or transmission seals have a hard flange, so without the factory tool you have to know how deep to drive the seals. I eyeballed the depths and it worked, but I wish I had measured the depths before removing the seals.
5) Make sure you have some long headless bolts to guide the transmission in and out without bending the transmission shaft or the clutch rod. It may be safer to remove the clutch rod before you pull the trannny off. Put it back after the tranny is bolted back on, but be careful with the felt pad on the rod.
6) If you really need to replace the crank seal, I recommend this "Coke can" trick

Is your clutch slipping? You can take a good look at the clutch by removing the starter. if it is contaminated by gear oil, you should see some splatter on the inside of the transmission tunnel.

 

[Flying banana]

Carlos, yer a good old boy, thats just what I was looking for, thanx. It is and 1150, and the clutch is definately slipping. It only does it when I give it some reasonable hard accelleration in the high gears, but its got worse and although its useable at the moment, it will need doing.
I did do the starter motor thing, which appeared to show that nothing had failed, and the plates were still well within service limits. However, it IS slipping, so its gonna have to come out to see whats what.
That link you speak of, I would be grateful if I could have that please.

Cheers,

 

[Arbreacames]

Phil,
Here is a thread that might be useful to you. It has pictures, part numbers, etc. In addition, look at the crank seal explanation by another Carlos from Portugal: Contaminated Clutch. Note that you don't need as much oil leakage as in the pictures to cause slipping of the clutch. I could barely see any oil traces. However, the small volume behind my clutch slave cylinder was flooded with gear oil, so it was a matter of time before mine looked as bad too.

Post your questions as you come up with them!

 

[Flying banana]

Thanks chap. I will check out that link fully tomorrow. I like the Coke can bit, that made me larf that did. I will however, be possibly looking at using that one, and amazing all my friends and relatives with my skill, and high tech tools

 

[Arbreacames]

Glad you liked the Coke trick (not my invention, by the way). As they say, seals go better with Coke.

 

[beermonster]

My bike had started to suffer from the dreaded slipping clutch problem. On getting to the clutch, found a bit of oil contamination but dry seals with the exception of the one which resides behind the clutch slave cylinder. There was a fair bit of oil when removed and the rod was covered in oil.

Any tips on removing and replacing this seal, screwdriver?

I have tried to remove the drive shaft as per Haynes prior to removing the gear box but the bugger refuses to move, any one else had a similiar problems, if so how did you sort it?

I ended up removing the rear sub frame (wish I had not), the motor appears to have pivoted slightly downward re-installing the sub frame will be a problem since the top engine mounting point is now out of alignment. Wonder if anyone has dealt with this problem?

Finally the collector box was a bastard to remove, got it off but the brackets are locked solid, currently soaking them in WD40, might have to resort to large hammer unless someone knows different.

Cheers for any help on these questions, have trawled the site for info and found some useful info already.

 

[beermonster]

Re - Assembly queries

Re - posting in case anyone missed my original post said he hopefully.

Simon

 

[Steptoe]

Errmm, perhaps a long pick ?? how do we know what tools you have ??
Just get it out using whatever means at your disposal. No secret tips, it's not rocket science, it's removing a seal .

 

[beermonster]

A reasonable selection of tools, granted it isn’t rocket science but maybe others have dealt with similar and could provide some tips. Sorry I don’t earn my living spannering and have not had to this job before so as they say every little helps - well maybe.

Cheers

Simon