The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Runninn1 on September 12, 2017, 01:01:43 PM
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86 R65 w/70k miles. After approx. 10 miles the rear of the bike (driveshaft/u-joint?) begins to ride 'rough' that is, feels like it is shuttering (my best feeble description). Could the u-joint be going bad? Ideas?
Thanks! :-?
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I think I would drain the oil in the shaft area and see if there is metal in the oil, of if the oil is contaminated with water, it will look like coffee with milk in it, if it is .
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86 R65 w/70k miles. After approx. 10 miles the rear of the bike (driveshaft/u-joint?) begins to ride 'rough' that is, feels like it is shuttering (my best feeble description). Could the u-joint be going bad? Ideas?
Could be a number of things - all bad sadly.
Firstly you need to eyeball the whole thing, I think that your 86 is a monoshock, I've not ever pulled one of these rear apart (but expect I will do so in the future as I now harbour an oilhead) but I am aware that the mono rear end is somewhat more prone to bearing failure than the dual shock iteration. Fortunately replacing the bearings in a final drive is well within the capability of a determined home mechanic (there is a video on youtube of someone successfully re-habbing their final drive in decidedly 3rd world circumstances.
If it is the shaft a number of people offer exchange services on refurbished shafts, if you can find an Emerald Isle reseller they will have a new replacement part at a fraction of the price of the BMW part and which has a good name for reliability.
If I am wrong and you have a twin-shock, the bearings are less likely to have failed, but you still need to eyeball your final drive - disassembly is covered by Snowbum and is also on youtube. A twin-shock shaft is a throw away and replace according to BMW, but who listens to them. The major problem is sourcing the universal joint which is extraordinarily difficult to find (but can be if you are persistent and tenacious) the sort of good news is that the universal joints used in a number of Honda "quad bikes" is near identical, unfortunately they do come at a honda spare part price.
As BMW did not expect the universal joint to be replaced they simply staked it in place instead of using circlips to retain it - this means that whoever works on your shaft must carefully machine off the staking so that the old joint can be removed in the usual way, they must then fit the new joint and carefully and accurately center the joint and then figure a way to retain it - the usual way is to spot weld some suitably sized washers to retain the joint.
Alternatively of course you can simply buy a 2nd hand shaft, given a clean environment the joint does tend to last a very long time.
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When the bearing went in my mono the bike would twitch when you hit a bump and there was noticeable side ways movement in the wheel. The problem was the drive hadn't been shimmed properly in the first place. The first place i took it to replaced the bearing and stuffed it up. It is not a job for the faint hearted.
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When in neutral can you hear anything clunking when you push it forward and backward?
The '95 R100RT I had developed a clunking noise I could hear when I would push it up in the garage. This was a number of years ago and I can't remember if I had any symptoms "at speed" but when I tore everything down it turned out to be the rear (output) bearing in the transmission.
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I have been unable to detect any clunking when pushing the bike and stopping (as outlined above). I did replace the transmission (used) about 5 yrs ago... if that even matters since I didn't replace the bearings. It may be best to find a used rear driveshaft. I will drain the driveshaft oil first & check the condition (milky, etc). To be cont'd...thanks (It's a monoshock)
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My '95 was a monoshock. Inspecting the drained lube as Bob suggested is the first step...
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Hi there Runnin, I think you want to see what the final drive oil is like as well as the shaft dive oil, as Tony mentions.