The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Hunsta on November 26, 2009, 11:14:04 PM
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OK riding home today from work I was two thirds up a hill (of course >:() and there was a bit a a clunk and then a loud grinding noise came from the gearbox and I lost all drive. Stuck it in neutral and no noise, but when I put her in gear she just sits there making a grinding noise like she`s stripped a gear or something.
Im not all that cluey when it comes to gearboxes, but looking in the workshop manual, could it be that the imput or output shafts have stripped? :-?
Tried to contacted my BMW mechanic, but he unavailable til monday, so I thought I`d ask the other experts in here.
I know its in the gearbox as when I got her home in the ute, I put her up on a block and spun the rear when in neutral and didnt get any noise. Put her in gear and there was a grind noise definately coming from the gearbox.
Any advice would be great. was planning a big ride early next year and need to get it sorted, and this time of year is hell to get anything done as Im not confident in doing the fix myself.
Cheers
Craig
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A gearbox rebuild is definitely specialty work. A LOT of airhead owners do their own and succeed, though.
I will send mine out when the time comes. The rule of thumb these days is to have a spare box sitting on the shelf to avoid downtime. And if you are off on tour somewhere, it can always be over-nighted to you, if need be.
I recommend doing as complete a rebuild as your wallet can handle. Replacing the bearings, is what I'm referring to.
~$500?
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bugger mate thats not good at all, as you said bad time of year for a major fix, hope you get it sorted out before your big rally run.
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G'day Hunsta,
If you are interested in trying to do the box yourself then this page may help:
http://jhau.maliwi.de/mot/gearbox.htm
I am pondering an overhaul but I don't think mine is anywhere near as bad as yours.
I know Motohansa in Sydney do recon gearboxes, but I suppose someone up there could provide them too.
All the best,
Paul
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Thanks guys. Took this a couple of hours ago. Cant do the youtube embedding thing for some reason so heres the link.
http://www.youtube.com/watch?v=GyvXXv3HATI
maybe someone can do a quick diagnosis.
Cheers
Craig
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Having seen the video i think it could be the input splines that have gone.Strip the box off to check it. If you dont want to strip the box yourself then best bet may be a reconditioned box from Motorworks 345 ukpounds fit it yourself easy job!!! with 12 months guarantee Motobins may have them too.
Lou
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I'd drain the oil out of the transmission, and see what it looks like, if it doesn't have anything more than the usual amount of metal fuzz around the magnetic drain plug, it most likely is the input splines have stripped, as Lucky Lou has mentioned .
One of our members, nhmaf had this happen a few years ago, I'm sure he'll post his pictures shortly .
The cost of the shaft alone, is around $300US, plus a gearbox rebuild .
The two pressure plates, clutch disc, and diaphragm spring are around $400US .
Can't over emphasize the importance of doing a transmission input shaft spline lube on a newly acquired R65, it's one of those maintenance items that gets overlooked quite often .
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When you begin to remove the gear box, as you will need to, a peek at the input shaft should give you some sense right away if it is the splines.
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Has anyone fitted either a Motorworks or Motobins reconditioned box? Looking at the price and shipping it is almost the same as buying one here in Australia.
Paul
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thanks for the imput(no pun intended). I`ll let you know whats gone wrong when I can get a chance to have a go at it.
Cheers
Craig
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The BM Shop in Brisbane (07 3356 6128) are wrecking a R65, saw it in "just bikes" mag (page 26), December copy..
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The transmision out of any compatabile year Airhead will fit - it doesn't need to be from an R65. When I rebuilt the transmission in the Dawg I used Jörg's page and everything went very smooth. I had put a complete rebuild tutorial in the Wiki, along with how to make some of the tools, but I have no idea what happened to it. I guess that's one of the hazards of leaving editing/modification open to users...
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Craig,
Good idea, that video. I was waiting for the other four gears, though. The frequency of the noise might have been a clue - i.e. if it was the same noise but the frequency changed with the gear ratios, one might assume it had to be the input shaft, rather than mucked-up gears. I agree with RobRoller - the next diagnostic step is to drain the tranny. Good luck.
Steve
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Having just watched the video for the first time, my instincts go with stripped input splines, as well. Mostly from the frequency and pitch.
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That scenario is basically similar to mine - when the clutch disk splines went and took off half the transmission input shaft splines as they ground down. Do NOT run the bike any more until after you've checked the transmission oil, and if clear, pulled the transmission.
On the "plus" side, I've got an article in our wiki that walks you through the whole process. It has plenty of photos so you can peruse it first to see what you should be on the lookout for. Good luck!!
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Well she`s going down to my BMW guru on wednesday for a look see. He`s a German guy who only works on BMW bikes. Has a rebiult bottom up 90s to die for.
So ill know whats what by the end of the week.
Stay tuned guys.
Cheers
Craig
ps anyone want to run a book on what it is? Winner gets "told you so" rights. ;D
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My guess is the main bearing has broken up, had this happen on my R45,
accelerating out of some bends and had a loud clunk and lost all drive, gear lever just flopped about.
Got the box out but didn't have a suitable puller to pull the drive flange off so got a rebuilt box from Sherlocks in the UK.
The special tool to pull the drive flange off is a hefty piece of kit and I am told when it releases from the taper it's likely to release with a bang and fly across the workshop so take care if you strip it yourself.
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Input spline or perhaps the spline inside the friction plate - the "Female" part. Especially if there is no chucks coming ou tof the oil at the tranny drain.
Hey time to run a Pole Justin!!!! ;)
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My guess is the main bearing has broken up, had this happen on my R45,
Welcome Colb. Good to hear there are other R45's out there but suprised that one could stress a gearbox to failure. I was counting on mine lasting for ever with only 35HP to handle.
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ps anyone want to run a book on what it is? Winner gets "told you so" rights. ;D
And the winner is..............................
drumroll please............................................
Yes those of you that said torn clutch centre wins. well actuall what has happened is the shaft that goes into the cltch centre stripped but as it was stripping it caught the clutch centre and ripped it out as well. MMMM yummy. Doesnt that just scream money. So a new clutch and associated bits going in and all and sundry thats needed. Plus new rear engine seal. About AU$1200-AU$1500.
There goes my christmas bonus. ::)
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Looks like 'Lucky Lou' gets the honors here !!!!
Serve him up a pint of Australia's finest !!!
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They don't call him Lucky for nuttin'. Monte
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You say your bike is a 1984? Twin-shock, right?
I have a complete used clutch assembly with under 38,000 miles on it, that you can have for the price of shipping.
Or, you can just have the clutch plate. I think that is the part with the splines.
It is the input shaft for the transmission that is the real killer, though.
I'm sorry for your troubles.
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I think I was in on that prize as well.... 8-)
Sorry for your failure though.... What year bike?
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You say your bike is a 1984? Twin-shock, right?
I have a complete used clutch assembly with under 38,000 miles on it, that you can have for the price of shipping.
Or, you can just have the clutch plate. I think that is the part with the splines.
It is the input shaft for the transmission that is the real killer, though.
I'm sorry for your troubles.
Thanks for the offer mate, but new bits are already on there way.
I think I was in on that prize as well.... 8-)
Sorry for your failure though.... What year bike?
Its a 1984.
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It should be noted that gearbox rebuilds can be made a lot easier by dispensing with the need for and expense of a depth gauge and truing plate. The shaft shimming can be set empirically with good accuracy via trial and error. In using a truing plate and depth gauge, I got variations of .02-.04 mm depending on where I rested the gauge and how hard I pressed on it to hold it steady on the small bearing race surface available. Getting the gauge foot to set true on the inner race was a nosebleed.
After reading every forum entry and tech article available on the topic on the web, it became evident that the _minimum_ shim clearance was not crucial as long as the shafts spun freely with zero preload, but just zero preload, no slop beyond that. Being that my margin for error using the depth gauge was almost that amount, it was possible to exceed recommended clearances given variations in gasket crush, running temperature, shim size steps, etc. The gearbox case is always going to expand at a greater rate than the steel shafts, so slop will always be introduced. If my measurements were towards the loose margin on assembly, the shafts could end up with more than .05mm at operating temperatures.
So I installed the shafts, one at a time, using thinner and thinner shim combos, until the shafts spun with a light amount of drag and then went .02mm thinner on the shims. The layshaft was turnable with a screwdriver via the output shaft hole minus its seal. This procedure involved removing the case cover many times (blow dryer for heating the cases) and care was taken to iinsure that it was tightened down equally each time using the clutch settings on a battery drill. As the shaft became movable with thinner shims, it was easy to gauge the lessening amount of drag when rotating the shafts, each in its turn, and when they turned totally free, it was empirically/tactilely evident.
The gearbox has several thousand miles on it and is quieter and smoother than ever before.