Gearbox Replacement

[Jim Eddy]

I have a 1996 R1100RT with 85,000 miles that really crunches when shifting between second and third and third and fourth gears once it is warm. I have cleaned and lubricated the linkage and replaced the gearbox oil with the specified grade and tried different gear change techniques but it has made no difference. I searched past posts and if I am correct the only options are to either rebuild or replace the gearbox. R1100 used parts seem to be pretty thin on the ground here in New Zealand but I have found a gearbox from a low mileage 1998 R1100S, does anyone know if it will be a direct replacement for the RT gearbox?

[Joelh]

does the transmission oil have a gold metallic color when you change it? Are you getting a "miss" when driving at speed? If not, then the transmission sounds pretty normal to me. My 01 has 50K and is very crunchy between 2nd and 3rd.. My previous 96 had the m94 transmission and was showing those signs of failure at 60K.

[Trullion]

The box from an 1100S will not fit. It is the later 6 speed box as fitted to the 1150RS et al.

 

If there are no particles in the oil, the box is otherwise quiet and it doesn't "skip" in 2nd or third gear then it might be ok. Is the clutch ok? If it isn't disengaging properly that will make changes harder. If it's the original it's as well to have a look at it. FWIW the m94 box in my 96 RS only lasted 34k miles, so you've done well to get to 85k miles. Best bet is to source a used M97 box.

[schneeman]

You say crunches, so not the usual clunk ?

Like others say, if oil is reasonably clear and no particles in it, then maybe it's not necessarily cause for immediate alarm.

With replacement second-hand boxes it's always a lottery (DAMHIK), and even when you get the M97 you still are looking at a potential input shaft bearing issue. If you come across a trusted source for parts and can get a decently priced used M97 box, then it's an option. Otherwise i wouldn't go there unless i really had to (i.e. current gearbox is falling apart).

Good luck,

 

[Gothicman]

I have a similar problem with the shift from 2nd to 3rd clunks, grinds tried preloads no different, plus I have changed the oil in the gearbox after 1000 miles twice and it IS coming out with a golden hew to it, does this mean something, I don’t know? And should I do anything, also I am getting a clunk when I shift, but have put this down to the backlash in the rear drive, if I engage 1st gear and take up drive I hear a clunk, and if I am trying to ride super slow in traffic as I have to ride the clutch a bit I hear it clunking on and off as I take up the bite of the clutch then release and bite and so forth, I thought it was the drive shaft so bought a replacement, but when I removed the shaft it showed no sign of movement on the uj joint or splines or on the uj joint at the final drive, just not sure what it is, and it is driving me batty, any ideas? Please!

[schneeman]

Hi Gothicman,

What year bike do you have, by which i mean which gearbox version M94 or M97 ? If it is M94 then the colour of your oil may mean trouble coming your way in a form of an inevitable onset of gear-skipping problem. The golden colour comes from the ground down shifting fork. It is metallic golden colour (just to make sure), not just a transparent gold of new oil, there are particles of the fork suspended in oil making it opaque (in a really worn case when the skipping is already present). On a M97 on the other hand it might mean the input shaft bearing is about to disintegrate, but i believe the colour is not golden in this case, but i never observed it myself so dunno.

As for the backlash/clunking, rather normal. Measure the backlash to be sure, 2-3'' is common in most gears.

Cheers