Rear Wheel Bearing Failure

[Ugly Cow]

the only drain plug to have a magnetic pluig is the FD can't think why?

 

[Ugly Cow]

Jees spelng is veri pore

 

[mikeyboy]

Yes I know the older bikes had problems as well and all the other models but I am just trying to draw everyone's attention to it. Most of the 1200 owners complaining bitterly think this is just limited to 1200 GS/A and its not. In fact even some 1150 rose tinted owners think its a 1200 phenomenon.

To the last question the very early FD had a different pinion bearing and these seem to be a guaranteed fail. No data on when they fail but I would imagine they are all pretty much changed now to the larger bearing which is a straight replacement. I havent heard of a pinion bearing failing in ages but in theory it could and still does happen. Sealed for life is not any more and is part of the service schedule to change the oil every 2 years same as the rest.

early gs from 2004 to 2006 had a 30mm o/d needle roller bearing fitted to the pinion inner,from 2006 the bearing size was increased to 32mm o/d,the bearing is NOT a straight replacement as the machined seat is also 32mm,the larger bearing seems to be better but has shown wear in all of the final drives i have worked on!.imho it would be poor practice to just replace the crown wheel support bearings and not to replace the pinion bearings at the same time,it would get rid of the play at the wheel but could give a very false sense of security as pinion bearing wear and failure is the main source of the oil contamination,and if this bearing collapses it will probably scrap the fd.mike

 

[steve1300]

where do you get them fixed i was told to buy the unit at £850 plus at piddies
41k and a bit noise

 

[Skid06]

can someone explain the all important shimming? do the guy's who refurb on this site do this or is it just a case of swapping bearings?

 

[TeaPig]

but could give a very false sense of security as pinion bearing wear and failure is the main source of the oil contamination,and if this bearing collapses it will probably scrap the fd.mike

Exactly

 

[TeaPig]

can someone explain the all important shimming? do the guy's who refurb on this site do this or is it just a case of swapping bearings?

in simple terms the shimming sets the clearances and the position of the contact between the pinion and crown wheel as they mesh together. It's necessary because tolerances
in machining of the pinion, crown wheel and FD casing means you just can't whack them all together and hope for the best. All makes of FD and things like differentials on car axles commonly require setting up in this way.

As bearings are usually very accurately made, the differences between old and new bearings is comparatively small so a common assumption, especially as the shimming process is a total pain In the arse requiring a range of alternate factory shims and repeated assembly and disassembly is they can be swapped without needing to change the existing shim set up. Maybe.

In an ideal world the shimming should be checked during the rebuild since it may have been done wrongly in the first place.

 

[Rasher]

In an ideal world the shimming should be checked during the rebuild since it may have been done wrongly in the first place.

Thanks for the explanation and the last bit is what I wondered about, in theory a very good rebuild with proper shimming is likely to be better than a new factory unit - but also a timely and highly skilled process (hence the inability of the factory to get it right).

I would be happy to pay more for a top notch rebuild if I knew all the bearings were replaced with high quality items and the gears shiimmed to perfection, and a breather added to allow the oil quantity to be increased again.

 

[mikeyboy]

where do you get them fixed i was told to buy the unit at £850 plus at piddies
41k and a bit noise

i can overhaul your unit,0115 9440666.mob 07786 340692 cost is @£360 ride in ride out,im ten mins from junc25 m1

 

[bsogri]

REAR DRIVES

Shims can actually be changed in situ as they fit behind rear drive cover plate