Differential Rear Spline Lubrication Interval

[Beagle]

Doesnt show or mention circlip . Groove in one but not the other picture

[David.]

Wethead drive shaft and snap ring (circlip).

[Beagle]

But is it in the U/J yoke or in the gearbox shaft?

[David.]

It needs to be recognised that the OP refers to a 2010 Camhead, I too have a Camhead.

Most of the replies are between a Camhead and a Wethead owner, there could be some confusion.

[David.]

But is it in the U/J yoke or in the gearbox shaft?

Reading the Haynes manual for a Camhead, the circlip is inside the front driveshaft coupling.

"Installation Push the driveshaft onto the output shaft until the circlip inside the front driveshaft coupling is felt to snap in its groove in the output shaft."

[Beagle]

Thanks that answers that.

[David.]

Looking at these two videos, it looks a lot easier to deal with the driveshaft gearbox end when the swingarm is removed.

https://www.youtube.com/watch?v=XYX7DynQkiM

https://www.youtube.com/watch?v=BsS8y6Y ... e=emb_logo

I have a friend who says, "if it ain't broke, don't fix it". Think I'll take his advice and leave well alone. Plus, I don't want to have to repaint the frame tubes.

More evidence to suggest why folks don't lubricate the gearbox end of the driveshaft.

[Beagle]

Think I’ll do the rear and just inspect the front with the Borescope and see.

[David.]

Further reading of BMWMOA and BMWLT forums would add more weight to don't even do the rear splines.

Providing both the F&R rubber boots are sealed and intact, leave them alone. A suggestion is, the action of removing the rubber boot for inspection and not sealing it correctly may cause more trouble than it's worth. If there is a surplus of white grease around the hinge seal from new, why disturb it unnecessarily.

The front shaft UJ to the gearbox output shaft is secured with a circlip. Therefore, there shouldn't be any sliding motion between the two.

Apparently, because of the suspension set up, there is very little or no sliding motion between the rear shaft UJ and the FD unit.

This may be why BMW do not list a maintenance schedule of lubricating the UJ's to driveshaft splines.

The universal joints are covered under warranty, which can be up to 80,000 miles at the commencement date. With only 28,000 on the clock, that'll keep me going for a few more years.

Perhaps all this lubrication palaver is a throw back from split driveshafts which slid between each other in the centre and required maintenance. Plus the GS boys who like to ride underwater and across rough terrain which may damage the rubber boots.

Is this all just BS, or does any of it make sense.

[David.]

20k on my bike, and look what I found today. Shaft had seized onto the bevel drive.

This would confirm that the rear driveshaft UJ to FD unit doesn't slide, otherwise, how would it be seized.

[Boxflyer]

Deleted

[Beagle]

Right my plan is this winter layup, do the rear final drive end with the Honda grease, check the front gearbox end with the Borescope and if ok spray liberally with this through the gaitor,


https://www.bearings-online.co.uk/item/2714/ROCOL/ROCOL-14015-Anti-Seize-Spray.html


This  is what I used on the Flapper valve.

[David.]

I'm trying to understand where the "necessary" movement which then potentially induces slide between the splines on the UJ's and the driveshaft comes from.
Any help to explain this would be greatly appreciated.

Meanwhile, have done some research (Googling) and come up with this, https://www.bmwmotorcycles.com/en/disco ... ardan.html

It explains how the rear suspension and power transmission work together. I'm drawn towards a couple of sentences.

"The paralever kinematics is designed so that no length change occurs, meaning no shift piece is necessary". Is this referring to the driveshaft splines.

"The drivetrain is maintenance-free on all BMW motorcycles, opposed-twin engines and K-four cylinders." No lubrication of the splines is required.

I could be wrong and may have misinterpreted what BMW have written. Just like to understand how things work.

[David.]

With an adjustable paralever arm, https://www.youtube.com/watch?v=TrKADp_guUg the FD unit pivots on the swingarm which will result in some sliding between the UJ's and driveshaft splines.

With a fixed length paralever arm, can't see where any movement comes from.

[Beagle]

Maybe if the drive shaft was fixed both ends there would be an issue of loading on bevel and gearbox bearings by the drive shaft lengthening and contracting due to temperature change.


Those photos would suggest there is a maintenance requirement.