Rear Brake Rotor Replacement-06 GS

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Re: Rear Brake Rotor Replacement-06 GS

Postby icedog75 » Tue Apr 05, 2022 8:50 am

I will probably time the inspection/greasing of the shaft splines with the changing of the oil in the rear drive so dropping the drive is just part of the process. I have a mity-vac so I could try that.
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Re: Rear Brake Rotor Replacement-06 GS

Postby Terry Rowley » Sat Apr 02, 2022 8:51 am

Longtime member Gary Oleson showed me a trick to drain the rear drive oil without having to take it all apart, and you can do it without removing the rear wheel. Obviously, this only applies to those with rear drives without a drain hole at the bottom of the housing.

You 'snake' a small diameter rubber or clear vinyl tubing down through the oil fill plug, between the rear drive gear and the rear of the housing, rotating the tire backwards while the gear pulls the hose down to the bottom of the housing. It's a little tricky at first but once you get it started it works great. It helps to first line the tubing up on the outside of the housing, then mark it somehow (I use a piece of masking tape) so you can gage approximately how much of the tubing should be inside the housing to reach the bottom.

Use a vacuum pump to suck out all the fluid, slowly rotating the tire back and forth slightly to make sure the tubing is really at the bottom of the housing to assure you've removed as much fluid as possible. Collect the oil and measure how much you removed. If you don't have any external oil leaks, then the amount of oil you collected is the same amount of new oil you add back to the rear drive.

The trick is to find a tube that is small enough to snake down between the gear and housing yet big enough to pull the oil out.
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Rear Brake Rotor Replacement-06 GS

Postby icedog75 » Fri Apr 01, 2022 1:37 pm

How many MC stories start "well I was doing an oil change when...". A $160 oil change from local BMW dealer reminded me that I did all my own maintenance on my FJR so rather than have the gearbox and rear end oil changed by said dealer I pulled out my Clymer and went to work. But that rear rotor was looking a little scruffy...pads were practically new but the rotor not so much. Digging out my 0-1 inch mic to measure...turned out the rotor was 0.2mm below spec. Now would that really present a braking problem...not so much...but I like the idea of knowing all was starting out from spec.

I don't know if anyone has priced a rear rotor from BMW but as you might imagine they are quite expensive. Nearly $350 with shipping. I'm all for factory but that's just unnecessary. I'd used EBC products on my FJR for years so thanks to the fine folks at Beemer Boneyard (and USPS priority) I had a new EBC rear rotor and a set of HH pads in 72 hours. Nothing special about the install except that for anyone who has done this how do you like the fact that there is only one location on the rear end that allows you access to the rotor bolts, and, even with a 6 inch torx bit it still didn't want to line up straight into the bolts. Seems like that could have been engineered a little better. In any case the rotor went on without a hitch and the braking feels exactly the same. :smt102

Rotor-1.GIF


Rotor-2.GIF


As for the oil changes, that was a different adventure. In this case Clymer is no longer correct in regards the proper amount of oil for the rear drive....200-220 ml has apparently become 180-190 ml....and since there's no way to actually draw oil out of the rear that's a job that got done twice. The positive is that after lubing the drive splines the first time around I've now got twice the experience in lining them back up again. I actually had no trouble with that part.

Later we can review the valve adjustment I did only yesterday...pro-tip here is after you finish the valves on the right cylinder, don't install the new plug until you do the valves on the left cylinder. It's really had to roll the engine over against compression. Who knew.
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