Gearbox whine

**John Roberts** · #1 9 Jul 2005

My gearbox whines at around 3,200rpm, irrespective of which gear I'm in, though it's pretty quiet at most other speeds. It's an R100RS, 1982.

Can anybody say from that what is likely to be worn, i.e. one bearing or the whole damn box? Is it ok to ride for a while or should I fix it nowthisminute? Any modifications that need doing while I'm about it?

Ta, John

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Johnefyn

**gsworkshop** · #2 4 Aug 2005

Your whine could be from bearing wear then I would suggest to monitor and if it get worse have them replaced asap, check my response on gearboxes in the same forum.
But I would suggest the whine is most likely to be more promenet when in fith gear witch suggest than the three helical gears is worn and pitted. They do not pose a thread but is an extremly expensive affiar to replace. This pitting will make your bearings wear at a higher rate because of the slight vibration.
If you have to replace the lot I can suggest the HPN fith and intermediate. The fith is 5% longer but is a lot cheaper and beter made that BMW serie parts, and the intermediate gear will save you having to replace the whole intermediate shaft with all its gears.
Check this site www.hpn.de

**dc lindberg** · #3 25 Sep 2008

Did you find out what whined ?
Sounds rather like it should stem from the engine...

**dc lindberg** · #4 17 Jun 2009

I tested a R100RT yesterday - its gearbox did whine preety much (!).
That whining comes from the hypoid sprockets:
Part 4, 11:
http://www.realoem.com/bmw/diagrams/k/u/0.png
1st gear is not listed as replaceable from BMW (that it is replaceable is another story).

My guess is - poor hypoid oil. My gearboxes have also had that sound... don't hear it since I use Omega 690 80W/90 GL7...

You do not need to worry ! -

That sound is normal -