Well guys the R1100RT has gone (not quite out of the garage yet though) and now getting the K back on the road has started in earnest. Tonight I pulled off the diff as it needs the bearings doing. This is not a task that I will attempt myself so I am going to take it to one of the local independant BMW guys (not a dealer). What sort of money should I be looking at? I spoke with the guy once and he indicated about $450/$500, does this sound reasonable. He said the cost is mostly down to having to use a genuine crown wheel bearing at around $270.

Second question. There seems to be a fair amount of what looks like it used to be grease (brown oily/gooy stuff) at the bottom of the seal where the final drive pinion enters the diff housing. I had a look up the shaft tunnel (swingarm) and there didn't seem to be anything coming from up there. The shafts have already been greased (both ends), but by a mate and he didn't mention any of this when we put it back together. Is my assumption right or should I also ask that the final drive pinion seal be done as well (if this is not part of a normal bearing replacement)?

Third question. The rear disk rotor looks naffed. I have looked on www.metalgear.com.au for a replacement and they list two different ones for the rear of the '89 K100RT. The one on the bike looks like it is held to a solid centre piece with 10 rivets. Is this another job for a guru (mechanic) to attach a new disk rotor?

If your thinking I am no mechanic, you would be right. So now that I am right into this expect more questions than ever. Once I have these two things sorted, a pair of hoops and brake seal kits done she should be good to pass rego.

Thnaks in advance.

Dave, I can advise as follows - Q1, I'm not sure how much a reasonable price is for a final drive rebuild, but if you can track down someone experienced other than a dealer I would guess at around $450 including parts (being only bearings and seals). I may be way off, others may have more info. As for the cost of, and needing to use a "genuine" crownwheel bearing, I don't think that is correct. If someone posts the bearing number I will get a price for an FAG one and post it here. Q2 The brown gooy stuff, gooy is remnant lube, brown stuff is fretting corosion from splines running dry (not good to see). Thouroughly clean the mating parts to ensure it is all removed prior to re-lube and assembly. Replace the input shaft seal when the rebuild is done. Genuine seal only. Q3 the new rear disc should come complete with its hub, just fix it in place with the 2 c/sunk head screws and you're done. Fit new brake pads though and bed them in by constant braking but not heavy to avoid overheating the disc in the first few hours. Hope this helps, Dennis

Thanks for that Dennis. It does not look like the splines have been damaged at all. The PO only put around 14000Kms on it (total is 119000) and had the splines lubed when he got it in 2000 at 105000kms. It has been unregistered since 2002 and then just sat. So I am hoping it is mainly just age and no damage has been done.

Unfortunately Metal Gear do not provide the disk with the centre hub so I will have to shop around I guess.

I got an EBC for the K1100 Dave, fully floating with a centre. Don't buy in Oz as you will be supporting Wayne Gardners very expensive habit of robbing people blind. Try to get it from EU or US round $220 and over $400 in Oz
They are the same disc as the K100

Dennis wrote:If someone posts the bearing number I will get a price for an FAG one and post it here.

Crownwheel main bearing: SKF 61917.
Crownwheel tapered bearing: SKF 30205 J2/Q, FAG 30205-A.

Inge K.

Got the bearing numbers, should be able to post a price Monday (12th) evening. Dennis

dave ...can i add ...check the input shaft / pinion for play in and out ....i can say that my other one had heaps of play about 2mm ...it apears as if the locking ring ...which also hold the seal in place might get some movement ...if your planning on replacing it anyhow you will no doubt be needing the special tool to undo the sucker ... the other bearings on the bevel look easy to change ...once you get the box split .. dont forget to replace the little seal between the 2 halves (cheap as from bearing suppliers ....and the output shaft seal is also common and cheap )

good luck mate

Thanks Charlie. Went to see the smart mechanic guy today and he thinks around $450 - $500 to do all the seals and bearings in the diff.

Seeing as I am a mechanical numpty and do not have near enough tools in my shed, I would be guessing I willl be taking it over to him on Monday. Should have it back in a day or two it seams.

[quote]Went to see the smart mechanic guy today and he thinks around $450 - $500 to do all the seals and bearings in the diff

Wow!! Thats good. i decided to give my local the job after being quoted $700 in brisbane. Ended up paying $1100, so no more work for him!!

[quote="Albyalbatross1"]

omg !!!

Do you have a break down of the cost of the labor and cost of the parts?
It is important to know if he charged you any money for shims and spacers.
if he didn't, it means that he never checked the backlash on the gears and only replaced the bearings and seals. This is not the proper way to do it but it's working. (I did it before and the bike doesn't have any issues).
Bearings are manufactured with tight tolerances and usually it won't make a difference.
You should really download the factory manual and ask him if he did it according to factory settings. (Crown gear is on chapter 33)
If he didn't, $1100 is robbery and you can let him know.
What type of warranty does he provides?

CF

Yeah, seems like highway robbery. Surname's Kelly??

I forgot to mention the reakdow.I pid for the rebuild kit from Munich. $500 (
I have since learnt) and the rest was labour.

Still Auch!

Seems like a good price for the job being done, provided as CF says they do eveything as quoted.

good one dennis ..

Thanks for the info Dennis. Took the diff in this morning to be told the crown wheel shaft looks naffed. This could mean the shaft needs a new spline fitted as well. Taking the shaft along with my second diff in tomorrow to see the best way ahead.

Might have to buy a new pinion and crown wheel, jusy have to wait and see. Looked today and a set can be had from the US for around $550 plus freight. Ouch.

One bright spot is the rear disk should be ready later this week.

Dave get a rear drive that is good, replace the seal and put it in. If you cant feel any play then there is a 99% chance it is OK don't spend too much as there are quite a few good used drives around.

Thanks for the info K Freak. Problem is the two lots of splines. The ones on the male pinion shaft are buggered and the ones on the female shaft side are not much better. At least the shaft can be cut and a new spline welded on. I guess the only fix for the other side pinion spline is a new one or a good second handy.

My feeling is this is my forever bike and it may be worth the $500 - $600 for a new crown wheel and pinion shaft set, to ensure I get another 200,000kms out of it. At least that way I start with a good base for the fuel pump and the diff/drive shaft. If I ensure maintenance is carried out regularly they should last my lifetime anyhow.

Just have to wait and see what the man says tomorrow.

Ok Dave, here's some info for you to be aware of - I too went for another used final drive unit for my '88 RT. I got one from the states but omitted to ask how many splines were on the input shaft. It had 16 when it turned up, but my original had 22. All the drive shafts have 16 splines at the gearbox end, but there are 2 spline variations on the FD end, 16 and 22 (as far as I'm aware). I think the 16 spline units may be earlier ?? Anyway, I then needed to buy another drive shaft to suit. So now in my shed there is an '88 final drive with no problems other than slight wear on the input shaft splines (replaced it as I just wanted the bike perfect for mainland touring) and also there is a drive shaft to match (16 x 22 splines). They are anyone's for $150 complete, shaft is perfect in the uni joint etc, I think the PO said he replaced it 2 years before I bought the bike (2005). This may help someone out. Dennis

sounds like a deal to be taken up dave ......even if just for a spare unit ...it will get you going and take an enormous load off the coffers at this time of the year ...not counting the dead lines that all buisnesses are trying to get over in the rush before the "big break "

There was a bloke on the Central Coast in NSW he was in his 80's when I spoke with him, He bought and sold K series BMW's He said the 16 spline pinion was the strongest. He never said why. He said the other could be rebuilt with a vw axle spline. I didn't bite with that one so he added they mill it down and mill in a key way in both and interference fit them with a (cant remember the name of it) peg. has anyone heard of this? has anyone seen a vw axle? As soon as I log off I'll remember the name of that peg. Interesting the 22 tooth arrangement matches the clutch tooth and its usually these that fail not the 16 tooth output shaft splines on the gearbox. Wonder if there is something to that. Keith

i believe you are right keith ....my old 16 tooth shows far less wear on the splines than the 20 tooth ones i have seen

for me the pinion movement was far too in excess to keep on riding on it ...and i have yet to date been able to make time to construct the keyed lockring tool to be able to tighten the whole thing up .

just looking at the mesh of the splines, it apears to me a if there is almost twice the face material interference on the 16 tooth spline than the 20 tooth i think i get my sums right if i said there is about 2-2.5mm mesh x 16 or 1mm mesh x 20 not only that ...the 16 tooth feels to have far less flex/ movement in the whole joint when mated up .... makes sence when we hardly see the output shaft end ever being reported as going bad it always seems to be the bevel box input playing up or the uni drying out ...

vw replacement parts wouldnt surprise me at all .....the germans hardly ever change what works well ...unless some foreigner gets involved and comes up with a way to sell more units ??? huh ?

Hi Charlie stopped for tea and then went into the shed, then it came to me, it was a woodruff key and the subject was the clutch, a 6volt clutch would fit ours and the vw people had splines that they resleeved they're stuff with, shrunk it on with a woodruff key, I thought it odd as our input shaft was hollow and didnt think much to it, till now, the marvell of the brain. I had wondered what would happen though, if I had pinned the F/D to the tailshaft and tried to use it, when I did my F/D in, but used all the K100 stuff on the K75 only bought a new tyre the rest was sitting there awaiting me to use it. This little foreigner would like some more units,both 3 and 4 cylinders please. I should go chase up on the sleeve solution for the F/D thats sitting in the shed now I guess. Keith

Hmmm, not too sure about the VW axle splines being close to our input shaft splines. I used to own a 74 Super Bug (with IRS rear suspension) and the splined live axles were quite a bit larger than ours from memory. As for not failing, the brake drum is locked onto the splines with a large nut, so no movement can begin. Earlier VW's with the swing axle arrangement are also quite robust at the spline end (other end is flat to engage in 2 half moon parts that form a clever uni joint inside the diff carrier (very simple but extremely reliable and clever). Back to our arrangement, the gearbox output shaft splines and the uni joint yoke don't give trouble because (in my opinion) they are fixed by the circlip and a closer fit initially so no movement is there. As for the other end, it needs to slide to account for slight change of length when the swing arm pivots, so the fit of the splined parts is different. As for reworking of the input shaft, there is a machine shop in the states, I think Bruno's ?? from memory, who extend the input shaft spline length by about 30 % so reducing the torque transmitted by each spline, apparently it is a very good fix from reports. Google it, I think there's plenty of info on it. And yes, I'm happy for someone to make use of my FD and drive shaft for the reasonable price (your postage costs). I also have a complete '88 engine in excellent condition but has loose output shaft rivets. $300 if anyone can use it. Dennis.

Thanks dennis that might save us spending too much time searching vw store in a vane hope we have a cure. the bruno's job does make brilliant sense 30more is good. Keith

The BMW guy here in canberra said there is a guy in Sydney who cuts the spline off the pinion and welds on a new one. If he will give me the details I'll post them here.

That might be the bloke motohansa uses they offer the same service. Keith

Bruno's Machine & Repair, Ontario, Canada. See, the 'ol memory isn't too bad after all ! I hope someone can make use of my FD & Drive Shaft, it's sitting going to waste. PM me if interested. Dennis

I have hear some very good reports from other forums and individuals about Bruno's work and in particular a very fast turn around service.
There are quite a few in US who send their repairs to him and gladly pay whatever extras because it is going in and out of Canada.

Dennis I's reccon we are all eyeing off the F/d of cause when Santa is breathing down your neck ya just don't get much breathing space. Keith