Drive Shaft Inspection

I have my bike apart for spline lube and possible clutch replacement and I noticed a slight notch in one of the axis of my drive shaft U joint. It is on the final drive side. It is still smooth but noticeable while the other three are smooth as silk. Should I be concerned?

Also, is there a way to measure the clutch disk without removing the clutch pack? The bike is at my shop across town right now I got to thinking I might not have to remove the pack and worry about aligning everything. The bike has 52K and the splines are good and I want to keep it that way.

Morning SmokinRZ

That notchy feeling U joint would be a concern of mine (that usually means the tiny needle bearings in the U joint cap have scored the U joint cross.

It probably won't fail immediately or even shortly but that notchy feeling is usually a precursor to U future U joint failure (NOW is the time to address it as you have the shaft in hand)

On the clutch disk thickness?-- sure you can measure the disk thickness (at least close) as you can access the end or outside of the disk.

But again- you are this far into it so (personally) I would want to remove the disk for inspection & inspect the rear main oil seal area. No big deal to re-align the disk but you REALLY SHOULD mark the CURRENT clutch pack parts clocking so you can get the clocking back to where it is now (this is VERY important vibration wise)

I removed the clutch pack and I am glad I did as the disk measures 4.53MM. Time for a new clutch and driveshaft.

Make sure that you check your pressure plates visually and with a straight edge. If you've got cracking then you should really be replacing them.

Also check the height on the diaphram spring.

If you just replace the friction disc and not the whole clutch pack, and your pressure plates are dished your clutch won't last as long. There will also be more adjustments that need to be made to your clutch as it beds into the old pressure plates.

You might be able to get this re-machined.

The bolts holding the clutch pack to the flywheel along with the star washers are according to BMW one time use, ran me about ~$25 two years ago to get a set.

Also at least on the R1100 they were 7MM bolts and I had to buy them from the dealer, I tried going to my local fastener warehouse and they only had them in sockethead screwcap.

Given the amount of time required to access the clutch it is best to replace all components including the spring. If you are riding an R1150 or R1100S you should replace the output cylinder too. Also take a look at the transmission input shaft seals. Now is time to replace them as well. If you are on an R1100 non S you will need to split the gearbox to replace rear input shaft.

Given the amount of time required to access the clutch it is best to replace all components including the spring. If you are riding an R1150 or R1100S you should replace the output cylinder too. Also take a look at the transmission input shaft seals. Now is time to replace them as well. If you are on an R1100 non S you will need to split the gearbox to replace rear input shaft.

Thanks, George!!

Duly noted.

Regards, and welcome to the forum!! You'll like it.

This is on a R1100, I will check the pressure plates closely and replace the whole clutch pack if there is any question. And the bolts and washers. I will check the clutch arm spring also.

My Clymer and Haynes manuals say to lube the spring plate where it contacts the pressure plate. I watched a few videos on-line and I don't remember anyone else recommending that. No trace of lube on the old one either. Actually there was not trace of lube anywhere. I sure don't want to contaminate a new disk with flying grease. I bought guard dog molly for the splines.

I tore the rubber boot on the rear brake master cylinder and it doesn't look like that part is sold separately. Does anyone have ideas on finding a replacement?

Apply grease sparingly.Use your thumb and forefinger to pull of the excess.

As for the boot check your local shop for a used one or try eBay. If no luck pm me and I will dig a used one up.

Thanks George, ordering parts this week.

Was cleaning the clutch arm bearing this weekend. I pulled out the throwout bearing/piston and cleaned it with brake cleaner and then got to thinking I maybe just washed out all the grease. Is the bearing sealed? I poured some oil on it and put it back in but now I'm wondering if it should be oiled? My manuals are back at the shop I'm working in across town. Waiting on parts.

Was cleaning the clutch arm bearing this weekend. I pulled out the throwout bearing/piston and cleaned it with brake cleaner and then got to thinking I maybe just washed out all the grease. Is the bearing sealed? I poured some oil on it and put it back in but now I'm wondering if it should be oiled? My manuals are back at the shop I'm working in across town. Waiting on parts.

Morning SmokinRZ

It sort of depends on if you have the old original piston or the newer fully sealed bearing. The later one is really sealed.

Oil won't last very long so they really need grease to last. If you think that you washed the grease out of the old bearing then you either need to replace the piston & bearing or try to work some grease into the bearing.

Ok, I think it is sealed, no way to take it apart. The bike is a 98 model. Thanks. Also, on a side note, I notice my american snap-on sockets fit better than the metric sockets on the few bolts. I hate tool marks.