The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Julio A. on April 30, 2011, 04:53:24 AM
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Finished the brakes. Everything was feeling fine already until I parked the R65 and touched the final drive. It was hot. Engine hot. I honestly don't know if it is normal or not since it is the first time I felt it after any ride.
I can assure that the rear brakes are not dragging and the axle nut is not torqued too much. The Driveshaft is still cool.
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Hey, Julio
I don't recall if you installed new rear brake shoes or not, but if you did, they may be in the process of "bedding in". Or the brake adjustment may be a little tight, or you may have laid hands on after a ride with lots of rear brake action. Friction brakes generate lots of heat that must be dissipated somewhere; the brake drum and hub being the primary cooling surface.
I wouldn't be overly concerned about the rear brake temps. What I'm kinda personally worried about is you sticking your little fingers into very hot places! ;D Don't do that no mo'.
And Julio, just another tip from an old guy... exhaust headers are meant to be hot. Hands off! [smiley=thumbsup.gif]
Monte
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Oh yes, I have learned the hard way that exhaust pipes are very hot way back in life. I also have the scars to prove it....
...I do have a tendency to stick my fingers in hot places. ;)
i'm kinda worried since the rear snowflake hub/drum is cool but the final drive is hot. I did just install new aftermarket brake shoes, but I'm kinda guessing that if the rear brakes are bedding in or dragging, the hubs should also be hot.
PS: I'm buying a temp gun.
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You do have 90 weight oil in the final drive don't you? Just asking.
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Yes, I do have 90wt oil back there.
But that got me thinking,
The rear drum did leak like hell last week. I tore down the rear assembly and replaced the brake shoes and stuff that got ruined by the oil. When the job was finished and I was fixing the front end, The bike was raised by 4 inches from the center stand and was inclined with the back end pointing to the ground. That's when more oil leaked even though I had a fresh set of o-rings at the cam. I never though about topping it up.
Oh well, I guess it's time for another round with the R65.
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I would definitely check your oil level, as well as check for tightness or wobbles in the rear wheel rotation in case you've got a bearing that is either in the process of failing or loose.
But, if you have been driving hard and fast and using the brakes, the final drive housing can get warmer than I'd like to leave my hand on it for long.
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May I ask, How much force should I torque the rear axle nut? :)
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May I ask, How much force should I torque the rear axle nut?
28 ftlb is the figure I have.
At the risk of encouraging more hands on temperature measurement I'll admit that I do it after a ride and while the final drive gets warm which is to be expected it's never as hot as the gearbox. Can't speculate on a temperature but certainly both way below 100 deg C and neither would inflict a burn at a quick touch. Differences in local air temperature to be considered though.
Providing there is some oil in there it seems more likely that binding brakes or a failed bearing would be the cause of excessive heat.
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Yes - regarding axle nut torque - it sould be in the 28-30 pound feet range and NOT "crank it on as tight as the lugnuts on a 1 ton truck category" - overtightening WILL put excessive preload on bearings in there.