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Final Drive decided to eat itself

bmwmotorwerkz

New member
A bit disappointed with having to rebuild my final drive about a month ago. Mileage, 39,700. The only symptoms were a slight oil leak and metal shavings in the gear oil. Turns out the crown bearing decided to start coming apart. Replaced the crown and tapered bearings, oil seal and o-ring. I decided to let my local BMW dealer do the work on this one. Total cost, $550. Of course, Labor was most of the cost.

I'm a bit concerned about the issues regarding the input shaft and clutch hub splines, but to date, I have no symptoms to indicate their is a problem so I think I'll ride it until something gives. The Dealer wants $1,625 to do a clutch service (new clutch hub) but that doesn't include the input shaft replacement if needed. If both are worn, both have to be replaced.

Chris at Affordable Beemer Repair (who many of you may be familiar with) offers a custom clutch hub that provides 100% engagement with the input shaft and solves the problem with the splines getting stripped out, as long as the wrench pays close attention to the clutch hub alignment procedures. Chris also highly recommends replacing the clutch slave while you're in there. Both custom pieces (clutch hub and slave) run about $725 shipped to your door.

I really don't want to get stranded somewhere in the middle of nowhere, so the options are to take my chances, or spend well over $2,000 for parts and labor to overcome bad BMW engineering and a mechanical problem that should have ended up as a recall.
 
In my admittedly limited experience with these rascals, the failure of the bearings is a symptom of improper loading of the bearings.
If it were mine, I would have a qualified mechanic such as Anton Largiador, or Ted Porter look at it. It won't be cheap, but you will know that the final drive is set up correctly. A friend of mine's R1100RT went through what you have described and we found failed bearings a few thousand miles after the bearing and seal replacement. Anton made it all better.:dance

Lubing the input shaft splines is a bit of a chore but not astro-physics. I have a check list for doing it that saves a lot of grief and if you email me I will send you a copy. Paul Glaves reckons they should be lubed every 40k miles, and he knows way more about these things than I. If you experience difficulty in downshifting, you are probably overdue for a lube.

I reckon that if your splines have not failed at 40k miles, they probably are properly aligned and will last for a long time.

Regarding the clutch slave cylinder; I assume you have an R1150. (Would be helpful if that info was in the title.) At that mileage, I think it would be OK and just need checking.Some have drilled a small hole below it so that if it leaks it will not contaminate the clutch, and the leak will be apparent(on the floor). My R1150RT has a bit over 80k miles on it and will get another spline lube this Winter, I suppose. Oh well, it keeps me out of trouble.
Welcome to the forum. Lots of good info and people here.
Jeff
 
In my admittedly limited experience with these rascals, the failure of the bearings is a symptom of improper loading of the bearings.
If it were mine, I would have a qualified mechanic such as Anton Largiador, or Ted Porter look at it. It won't be cheap, but you will know that the final drive is set up correctly. A friend of mine's R1100RT went through what you have described and we found failed bearings a few thousand miles after the bearing and seal replacement. Anton made it all better.:dance

Lubing the input shaft splines is a bit of a chore but not astro-physics. I have a check list for doing it that saves a lot of grief and if you email me I will send you a copy. Paul Glaves reckons they should be lubed every 40k miles, and he knows way more about these things than I. If you experience difficulty in downshifting, you are probably overdue for a lube.

I reckon that if your splines have not failed at 40k miles, they probably are properly aligned and will last for a long time.

Regarding the clutch slave cylinder; I assume you have an R1150. (Would be helpful if that info was in the title.) At that mileage, I think it would be OK and just need checking.Some have drilled a small hole below it so that if it leaks it will not contaminate the clutch, and the leak will be apparent(on the floor). My R1150RT has a bit over 80k miles on it and will get another spline lube this Winter, I suppose. Oh well, it keeps me out of trouble.
Welcome to the forum. Lots of good info and people here.
Jeff

+1
 
Welcome to the forums!

I'm not sure from your post if you want to work on your bike or not.


If you do like to wrench then:

Winter is coming up which gives you lots of time to do the spline lube yourself.
I'd take up Jeff on his offer of the checklist and hunt around a bit to get some other input. Lots of folks here have been through this and can provide pointers.
Take care raising the tail, we've had a few problems when bolts have been left tight in error.

You can check the current condition of the splines by removing the starter and observing the play in the spline.

If we're voting:
I say do the spline lube, hopefully all will be well and you'll be good for another 40K miles as well as knowing the condition.
 
Great info, and thanks! I did take Jeff up on his offer and he was quick to send the procedures along with some other info. Appreciate all the help.

I just got a look at a clutch hub off of an R1150 with 30,000 miles. The splines were completely worn down to the point that the input shaft wouldn't bite any longer. Input shaft was somewhat better but had lost about 50% of its spine.

So, I'm not sure mileage is a good basis for when this might happen and instead, its most likely whether or not you have a proper alignment, whether its lubed when needed and, whether or not your shifts are smooth or abrupt.

I have a little over 38,000 miles now and my clutch locks up very well without any slippage however sometimes when adding throttle from low speed I'll hear the 'metallic click' which I think is the pinion engaging into the final drive hub gear.

Colorado Euro did my FD rebuild and said the pinion and hub spines looked very good so I don't have much wear back there. Luckily I caught the final drive issue very early.


Sent from my iPhone
 
The author is not named in the document but it belongs to awagnon and it's really well done. It's great to read the list and visualize what you will be doing and what you may need on hand to do it.

I also notice he's been updating it too. This list came up in a thread sometime in the spring and since I knew I was going to dive in on my 1100 at some point soon (@39K miles now) I downloaded v02 23 08. But I see this is v03 26 11 and in a more universal .doc format.

Thanks awagnon!
 
Oooops, I forgot to put his moniker in there.
He's my hero, I just help spread his knowledge.:bow
 
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