The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Darwin_R65 on March 21, 2009, 07:44:53 PM

Title: Rear drive Teeth
Post by: Darwin_R65 on March 21, 2009, 07:44:53 PM
Well my brakes were playing up yesterday, the rear brakes seem to be dragging, so off with the rear whell (Not as easy as the book makes out when you've got pannier racks on. Solution was to jack the bike higher)
And the problem seemed to be red GREASE everywhere.
It appeared the spline had been lubricated with a high temp bearing grease and this had run everywhere.
So I bought two cans of brake cleaner and attacked everything, then I noticed hmmmmm, the teeth on the spline seem a bit narrow. Thought I'd show a piccie, I've looked up a replacement on munichmotorcycles and the new spline is listed at AUD$310.

Has anyone got any advice on how hard a job this will be, and what else you reckon I should be doing, I guess the whole rear drive probably should have all seals replaced while I have it apart. Bearings/bushes?

Munichmotorcycles recommends a good quality graphite grease for the splines, but after going to Repco, SuperCheap, Independent Motor Mart, they all told me they don't stock graphite grease. Actually the Repco guy asked what it was for and suggested Graphite powder, as I was on the phone he couldn't see then bash my head against the wall.

On Monday I'll try CBC bearings(I was looking 2 hours after they closed on Saturday).

John
Title: Re: Rear drive Teeth
Post by: nhmaf on March 21, 2009, 08:23:23 PM
IF you do take it apart to replace the spline gear, you should plan on using new seal for the center axle/spline and there are 1 or 2 (varies with year) seals on the rod which goes thru to operate the brakes.  Plan on new 'wave' washers for going under the cover bolts around the outer edge too.

It sounds like someone was overly generous with the general purpose grease - at least they did have the thought to put something on there, even if it wasn't a great choice.   What you want on those is an even "schmear" or coating (not big gobs) of a fairly sticky paste grease, preferably with a fair amount of moly  in it.
There are a variety of brands available in the USofA - one of the most frequently used brands can be obtained here at Honda motorcycle shops (might have to be ordered, though) and is refered to as Honda Moly-60.  It sticks to stuff well and is designed specifically for applications like spline lubrication.

IF t'were me, I'd clean up the brake shoes - replace them if too contaminated, clean everything up and put some moly paste on there with an old toothbrush and ride it.   It does look like your splines are getting worn and you will have to plan on replacement
by year's end depending on how many miles you rack up.  Once the splines get to a pointy knife edge they can strip/fail and spoil your day.  The should have a more "square" profile, like this:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi159.photobucket.com%2Falbums%2Ft138%2Fnhmaf%2Frearspline01.jpg&hash=651a650d7d8a137fb144dcd22fc81f0c297dc8a6)

You can probably score a used final drive in good shape for less dosh than buying a new spline gear.  I found a complete final drive with very good splines on ebay a while ago for about $125.  Also, I have heard that some talented machine shops can repair/rebuild the splines by welding material back onto the teeth - I confess to never having seen this done, but some claim it is possible.
From what I can make out from your image, I think you have a bit of time yet, but I'd be planning for a repair/replacement either before too l
Title: Re: Rear drive Teeth
Post by: Bob_Roller on March 21, 2009, 08:25:45 PM
Those rear wheel drive splines are worn to the point where they need to be replaced, that's quite obvious !!!

The only real concern would be to properly shim the 'ring gear' for proper engagement to the pinion gear after replacing it.

Replacing the other seals are not real technically challenging.
Title: Re: Rear drive Teeth
Post by: Justin B. on March 21, 2009, 09:05:05 PM
I would be inclined to start haunting e-Bay for a used one that had good splines...
Title: Re: Rear drive Teeth
Post by: donbmw on March 22, 2009, 09:45:18 AM
You can have the rear splines reworked. I had that done on my 75 R90/6 back in 1987. They are still in good shape to this day. Bobs does this and there are someother places that do this.

Don
Title: Re: Rear drive Teeth
Post by: Bob_Roller on March 22, 2009, 09:58:12 AM
There's a repair shop in Medford,OR., for those of you in the western US, that performs final drive spline replacement.


http://www.hansensmc.com/

Normally to have the part stay under warranty, it requires replacing the 'drive dog', that's the splined part that is riveted to the rear wheel, as well.
Title: Re: Rear drive Teeth
Post by: nhmaf on March 22, 2009, 03:32:05 PM
Bob brings up a good point that I forgot to mention earlier - what do the mating splines look like on the wheel hub?   It is very possible that they are pretty worn down too if the drive splines are worn that much.
Title: Re: Rear drive Teeth
Post by: Darwin_R65 on March 22, 2009, 04:20:40 PM
the mating spline looks perfect.
go figure.

John

Title: Re: Rear drive Teeth
Post by: Bob_Roller on March 22, 2009, 06:11:09 PM
The hardness of the 'drive dog' on the rear wheel , is a lot higher than the ring gear splines.
Title: Re: Rear drive Teeth
Post by: Semper Gumby on March 23, 2009, 09:44:56 PM
Nathan at Boxerworks sent mine out somewhere.  The cutoff the old splines and welded on a new set.  I got new seals but the internals were all good.  Much smoother.

TTFN,
Title: Re: Rear drive Teeth
Post by: plc on January 12, 2010, 12:25:39 AM
Hi All,

Sorry if it is bad form to resurrect a thread. How did you go with the rear drive splines John? Did you replace them? If so did you buy the replacement drive gear from Munich motorcycles?

Siebenrock sell this (at top of page):

http://www.bmwbayer.de/index1.php?ref=www.bmwbayer.de/02/0201.php&sprache=en

Yet Motobins do not sell anything like this and I could not find such a part at RealOEM.  Has anyone used such a part?

My splines are about half to two thirds gone and I am investigating options. Is it hard to fit these parts? How does the ring gear attach to this spline, I see no mating spline or such, is it merely a taper using friction?

Best to all,
Paul

Best to all,
Paul
Title: Re: Rear drive Teeth thread resurection
Post by: Semper Gumby on January 12, 2010, 09:48:31 AM
No worries plc.  Payment for advise rendered is sharing your experiences here so that all may benifit.

I'm wondering too.
Title: Re: Rear drive Teeth
Post by: Bob_Roller on January 12, 2010, 10:00:21 AM
Best guess, is that the old ring gear is cut and milled out to accept the new part .

Probably an interference fit, the ring gear is heated up, the new spline part cooled down, then assembled .
Title: Re: Rear drive Teeth
Post by: plc on January 12, 2010, 02:47:34 PM
Damn, that doesn't sound like a job I will be doing on my own.

Paul