BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

That discussion about the 19 vs the 17 ball bearing has been around the hill and back, but I thought sure the newer improved one would be offered these days.

Phil - my understanding is that the old 19 ball bearing was replaced with a 17-ball version and has been replaced again with another 19-ball version. Since I just had mine done, I am holding onto the faith that the quality of the metal is the improvement rather than the number of balls!

I believe I got that info off the website of some BMW guru in Virginia. Forgot the name! Anyone else know?

iowabeakster wrote: 1--Would you reccommend (or not) the idea of pulling the whole rear tire/FD/paralever/tranny as a single unit and rolling it back?

2--What did you use to make your guide pins?

3--Why does BMW reccommend new bolts (tranny to engine), and why did you reuse yours?

--Answers--
1--Yes. That's the method the BMW manual recommends for a clutch disk replacement, but they are also likely using 3 guys to handle the long, heavy, unbalanced heavy mass. I had other systems that needed attention, like the slave drain addition, FD bearing inspection, throttle box internal cleaning and cleaning/polishing the exhaust system that were made easier because the throttle cables were already disconnected, the wheel was already off and the slave was totally exposed after the swingarm was removed.

2--I used one 8mm diameter x 1.25mm thread x 115mm long cylinder stud and another bolt the same size and length with it's head cut off, both salvaged from a junked engine sometime in the distant past. I save all that good stuff in painted over coffee cans for important needs just like this. You can see the Guide Bolts in the pic below labeled "HomeMade Guide Bolt". They are supposed to go in the same holes at the 10:30 and 5:00 O'Clock positions where the locating dowels are on the motor. Notice the screwdriver slot hacksawed in the stud's end so you can install/remove it.


3--The clutch was being discussed and it's those pressure plate mounting bolts screwed into the flywheel that must be replaced, not the transmission mount bolts. Those pressure plate mount bolts actually are tightened so much (install torque + 32 degrees additional rotation) there's permanent deformation, so they aren't reusable. Since they turn with the motor and must NOT ever loosen up and back out, "special bolts" are required.

Edit: to fix broken link and change photo provider to a better one.

CycleRob wrote:
I used the 2 heat sources to evenly heat the area extending almost a foot (30cm) away. It's common sense to not do extreme localized heating on an Aluminum casting, but that was not covered in the manual. Heating a frigid Aluminum casting like that should worry you as the Rockster pic I linked to above ("Common Sense") most likely shows.

.

Is it proven that localised heating was the cause of that failure? I didn't know if it had been established who's bike that was and what had been done to it?

riceburner,
No, it hasn't been established localized heat is what caused it, but take a close look in the picture where the breakage occurred. Right in the pivot bolt heat zone areas.


The problem is that Aluminum has a relatively high Coefficient of Thermal Expansion and cast Aluminum isn't very flexible while also being susceptible to thermal stress cracking from spot heating. There's practically no other way for a failure like that to occur, except maybe a previous rear end collision.

CycleRob wrote:riceburner,
No, it hasn't been established localized heat is what caused it, but look in the picture at where the breakage occurred. Right in the pivot bolt areas. The problem is that Aluminum has a relatively high Coefficient of Thermal Expansion and cast Aluminum isn't very flexible while also being susceptible to thermal stress cracking from spot heating. There's practically no other way for a failure like that to occur, except maybe a previous rear end collision.

Rob - just wanted to clarify that I didn't think you were wrong about the cause of that failure (I'd say you're very probably right), but I just didn't kow if it had been proven.

Like you say, it's highly likely.

Rob-

Many thanks for all your efforts and detailed information. This will be invaluable to me this winter when I attempt to do the same.

Wayne

Your meticulous work and the clear pictures are like a navigation compass that takes one to distant lands and brings you back home safely.

Excellent job. We salute you.

M Khan

Wow - Rob - I never knew about this post until today. Your detail is without equal.

You should come visit me for a week and I will feed and beer you to meet your requirements. I would love to do this (2004 R1150RS with 15,xxx miles) but this level of dissection gives me the willies

Mapquest says 9Hr 48Min and 580.40 miles to main street of your town. That's way too heavy a lift for me. You could ride to my Gainesville GA home's garage and spend 2 days here, but it would suk if it needed parts.

The time consuming take-apart is not that difficult, but it enables the inexperienced to cause some very expensive damage(s). Specifically, Breaking the plastic fuel rail during the frame lift. Stripping the fine threads in the Aluminum swingarm pivots from misalignment or by insufficient or over heating the pivot bolt area. Bending the still in place clutch pushrod on transmission removal. Assembling the splined driveshaft U-Joints out-of-phase. Under or over tightening critical bolts. Using too much or a sloppy thread locking agent application and seizing the needle bearings. That's the short list off the top of my head.

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Breaking the plastic fuel rail during the frame lift.

Now I can't imagine who would do that!