Spline Lube, Carb rebuild and rear bearings.

[Julio A.]

I'm in vacation finally!

Since I got time to burn for now, I'm doing a Spline lube, a carb rebuild and i'm looking agian for the persistent source of excessive heat from my final drive.

I already have a carb rebuild kit for both my carbies, and I noticed that my jets are also in need of replacement. Does anyone know the jet sizes and any tips or tricks that might help me when i'm down there?

My second problem is the persistent heat from the final drive. When I replaced my rear bearings back then, the problem disappeared for a short while before it resurfaced again. I'm opening the rear wheel tomorrow and see if the bearing are indeed the source of the problem.

The last and the one i'm most hesitant to tackle is the spine job. Although i do need to do this one since I also have to replace the clutch pushrod cup since it disintegrated a few months back, possibly letting excess moisture in there. Any tips or tricks would be helpful.

[Barry]

With the exception of the needle jets which are worn oval by the needle, carb jets don't usually wear. So unless damaged I wouldn't see the need to replace the idle or main jets.


Never been inside the final drive but they shouldn't run very hot. Mine is always significantly cooler than the gearbox.


The spline lube is harder in the imagination than in reality at least that's how I found it.

There are a number of detail write ups around on the net but if you are only pulling back the gearbox 1" to do the lube then in principle it's just remove airfilter housing, battery and carrier, speedo cable, rear brake rod, unbolt the gearbox and remove the swinging arm pins. Support the gearbox with a jack then operate the clutch to break the initial stiction between engine and gearbox before pulling back the whole gearbox/swinging arm/rear wheel assembly. Take care not to damage the neutral switch under the gearbox. Special tools needed :- a flat faced slim wall or ground down socket for the swinging arm lock nuts and a length of rope to pull back on the rear wheel and maintain the gap.  

The only thing I stuffed up on was removing the circlip on the clutch operating arm pivot pin. It sprang off in a graceful arc and disappeared into a flower bed.  I searched for ages with a megnet without sucess. As it was a Sunday I had to make a substitute clip from a washer before buying several proper spares then the original turned up surprisingly free of rust the next spring when I was raking out the bed.

[Julio A.]

Regarding the Spline lube, do I have to unbolt my suspension?

My Final drive is a mechanical anomaly. I think it has something to do with the wheel bearings. I just had the final drive itself done and it was properly shimmed and the large crown gear bearing was in good condition. What really bothers me is how could my wheel have a really really tiny side to side play even if I torque it down tighter than what the manual tells me. So I settled by torquing it down to proper spec even with the sub 1mm play.  

Could the fact that I installed the rear bearing stack without the plastic spacer be the problem there?

[Bob_Roller]

The two plastic rings that go over the metal spacer between the bearings, is to keep the spacer from moving excessively while assembling/installing the bearing/spacer/shim stack-up .

I checked my final drive for temperature when you first mentioned your final drive was in your opinion, running hot about 6 months ago or so .

I checked mine on an 85 F. day, after 40 miles at 75 mph, the final drive to too hot to keep your hand on it for more than 10-15 seconds .

[montmil]

... What really bothers me is how could my wheel have a really really tiny side to side play even if I torque it down tighter than what the manual tells me. So I settled by torquing it down to proper spec even with the sub 1mm play...

Don't know if this comment could contribute to your "hot" rear end (now THAT didn't come out right) [smiley=whistling.gif] but here's a couple things to check out:

The little "top hat" spacer/thrust sleeve, visible on the exterior face of the left side rear wheel bearing's inner race -with the top hat's brim under the grease seal- and a second one accessible with the rear wheel removed, are available in a multitude of increments of length. These help to establish bearing preload, and could be contributing to the slight side-to-side movement of the rear wheel.

Or... there is, IIRC, a spacer ring that mates up against the rear axle bushing tube that could be worn down or the incorrect thickness. Item #4, I think. These spacers are also available in several thicknesses.

http://store.bobsbmw.com/microfiche/BrowseParts.aspx?GroupName=Rear+axle%2c+rear-wheel+drive%2c+suspension&MBike=51897&GroupID=33

Since you'll be in there...

Enjoy your working vacation, Julio.

[Barry]

Regarding the Spline lube, do I have to unbolt my suspension?  

Not if you are using the pull the gearbox back 1" method.

There is the alternative method of removing the whole gearbox which will involve unbolting  the drive shaft from the gearbox output flange which would usually mean removing the rear wheel (you are doing that anyway).

[Julio A.]

I just opened the rear wheel up,  I am missing the wedding ring.

I posted a picture on what was inside the wheel. Nothing except the bearing races was left there. Am I missing any other parts?

the order is Tophats(from both ends) Bearings(both ends) plastic spacers(both ends) and the metal pipe at the middle.

Anybody know a technique so I can have one machined at almost the right length? The wedding band does have the same inner and outer diameter as the steel pipe right?

[Bob_Roller]

There are shims that go in between the spacer and 'wedding ring', if you need them to get the proper preload on the bearings .

From the look of the parts catalog, BMW may not be selling the thin shims anymore, it looks like the 'wedding ring' is available in varying lengths now to give you the proper preload .

http://www.realoem.com/bmw/showparts.do?model=0364&mospid=51897&btnr=36_0146&hg=36&fg=10

[Teo]

Hi Julio,
You can hone the wedding ring to the proper width on a whetstone.  It is a trial and error method but will result in "perfect" fit for your bearing preload.  If you hone off a little too much, Dwayne Ausherman has shim kits for about 10 bucks that provide 5 or 6 varied thickness shim washers to adjust the preload.  As far as I know, all Airhead rear wheels that are dual shocked have a 17mm axle so Dwayne's shims and the wedding rings are universal.
Patience and good luck,
Teo

[Rob Valdez 79 R65]

Dwayne Ausherman has shim kits

Contact info:
http://w6rec.com/duane/bmw/index.htm

Send him your request.  He will ship the kit ASAP and you can send him the money ASAP as well.  He still believes in the honor system.

Go to nearly the bottom of this page for specific information:
http://w6rec.com/duane/bmw/wheel_bearing/index.htm

[Julio A.]

I got the shim part, and I might be ordering from him when i see a way to pay him back.

I measured the free play between the two bearings while the pipe is there. It seems I will be starting from a 4mm spacer and shim (or hone) it to perfection.

I will locally fabricate a wedding band. I already have my inner diameter and length. I don't know what the outer diameter should be.
Found dimensions courtesy of Dwayne Ausherman. )

[Julio A.]

After some time. I was finally able to get a suitable replacement for the wedding band.

I got copper washers made with dimensions of 17mm id, 24mm od, with a  thickness of 1.5mm. I stacked 4 of these washers to get a 6mm thickness.

Doing the shake while tightening test as suggested by Dwayne Ausherman, A 6mm thickness was too small of a preload while a 7.5mm thickness was too much.

I sanded a single washer until it was just enough. I eventually ended up with somewhere around 6.5mm.(I was only using a cheap caliper, which isn't very accurate)

The free play went away at around 25 ft/lb, which is about ok.

The first thing I noticed was the smoothness of the rear wheel. It took a lot less force to rotate it.

I'm riding highway tomorrow to see if the final drive heats up excessively again.  

[montmil]

Sounds as if you did well with the repair. I, too, have sanded a few washers. Sometimes, it's the best solution.

Enjoy your ride. Hope your hot rear end cools down. [smiley=grin.gif]

Monte

[Mike V]

Julio,

Be careful.  Bearings are a serious safety issue and even though a washer may work well I urge some diligence and careful attention.  Personally, I would suggest the correct wedding band size after careful preload determination with a quality take-up spacer and torque wrench.  Just my personal opinion.  My personal experience is with different /7 and /6 models, not the R65.  Never exceed 35 Ft-lbs on the axle nut.  If washers do the trick - more power to you.

Please report back after your test ride, I'm interested to hear how things turn out. Did you replace the grease seals?

-Mike V. / Rainy, windy and cold San Diego

[Barry]

I've sanded a few washers in my time to make shims but not in such a critical application. I'd echo Mike V's caution. Besides the fact that it's near impossible to sand a washers to a consistent thickness and keep them parallel after all we are talking tolerances of less than a thou I would be concerned that copper is too soft for this application and may spread under the applied compression. Running a quick calculation 25 ftlb of torque on what I think is a 14mm thread will produce a clamping force of 2700 lbs. That's over a ton on what is probably a very small area. I suppose the test will be to check the torque necessary to remove all free play after a period of running to see if there is any change. If it drops your washers have spread. You've solved the problem Julio which is great but now you know the correct dimensions it might be better to get a proper wedding band as Mike suggests.