1990 K75s Swing arm bearing play?

Good afternoon all!! Whilst cleaning up the rear swing arm preparing to give her a little tlc, I noticed that the swing arm bearings had some play. Basically if I put my finger in the center race where the pivots would go, there is some in and out play. Looks like the bearing outer is pressed in flush with probably a flange surface so can't be pushed in further, but can be pulled out slightly. Talking fractions here.
Is this normal? Or should they be completely solid in all directions.

Thanks in advance to all you gurus!!

With the swingarm out (I gather that's what you're talking about), the bearings will have some axial (in an out) play. Push the center of the bearin in and rotate it. If you feel roughnes in its rotation, you might consider replacing.

Otherwise, install swingarm and tighten the preload pivot pin to 60-67 INCH/lbs. Feel the final drive end for smooth up and down travel and NO left right movement.

Thanks Lee!! Once again an incredibly timely response with exactly the info needed.

Yes, I have the swingarm out. One side clicks a little when turning the bearings, so I will be replacing them.

I just pulled the gearbox off. The splines all look good. Need to pull clutch pack tomorrow so I can measure the disc and I think due to the bike having sat for 10 years, I will be replacing the rear main seal. I think it is probably silly not too while I am already there. Would hate to start her up just to see leaks

You did mention there is an o ring that I should replace? Is that after I take off the clutch pack? Also, sorry to be a PITA, but watching one of the Chris Harris videos on trans removal, when he pulls off the clutch boot, removes spring and then the puck, there is a bearing there that he removed. Is that unique to the K100. I have a 75S and do not have that bearing. The only thing I see is a snap ring further into the trans. Does that make sense?

I really appreciate your input and advise. If you are ever down in SoFla, I will def buy you a beer!!

BEFORE YOU PULL THE CLUTCH PACK!!!!!!!!:

Be aware that there are 4 main pieces. One is the clutch disc. The other three are metal pieces; clutch housing, pressure plate, and housing cover, from engine back with the clutch disc between the pressure plate and housing cover.

It is EXTREMELY important that the three metal pieces go back together in the same orientation to each other as they came out in. Since there are three pairs of bolts holes on each piece, each piece could be reassembled in any of three ways in relation to the other two pieces.

Each piece is slightly out of balance and when assembled at the factory, is positioned to cancel each other out. If assembled so that the heavy spots all line up, you'll have a very un-K75 like vibrating machine. The factory balance marks wash off easily or may not be visible, so ALWAYS mark the three metal parts BEFORE you disassemble. Mark with heavy scribe marks or centerpunch marks so that you KNOW they are reassembled in the rotational orientation that they came apart. Do not mark with anything that could come off with solvents.

The O-ring is behind the nut and spacer that hold the clutch housing (where the flywheel would be on a car). This O-ring is the most common causes of leaks into the clutch area.


The bearing Chris was refering to was used on '88 and older K75s and K100s. After that, the bearing and piston were combined into one unit, your "puck".

Awesome advice again Lee! You obviously know more than me when it comes to this bike!! If you ever buy a Jag and need help, I'm your guy!

I'll be tackling the clutch tomorrow AFTER everything is marked first. It's a shame BMW did not off center one of the bolt holes so things could be installed only one way. What do I know??

I did order the progressive shock per your advice also!

Thanks again for your help!

When installing the transmission, pack the splines on the input shaft of the tranny with grease (I use Honda Moly 60 with some "additives") but NOT the splines inside the clutch disc. Any excess inside the clutch disc hub would be pushed through the hub by the tranny shaft and slung onto the friction surface of the clutch disc. Not a good thing! However, any excess on the trannyshaft would be wiped off by the end of the disc hub that is well offset to the rear of the friction surface, where it will harmlessly sling off to the inside of the intermediate housing (bell housing).

I clean the hub splines and then "precharge" them by filling with fresh grease and sliding the disc in and out on the tranny splines while twisting left and right for a couple minutes. Then I wipe off all the excess. This leaves a very very thin coat of grease on the hub splines (nothing that could be pushed through), but fills the pores with moly. Then install disc, pack tranny splines, install tranny.

I have some Wurth 3000 that I was going to mix with the Honda Moly 60. Also I have Staburags grease for the input shaft. Should I not use that?
I did notice that there was a lot....and I mean a lot of clutch dust inside the bell housing. So I'm not anticipating reusing the clutch disc. I'm going to likely clean it up a bit prior to removing the clutch pack so I can actually see the marks I'll put on.
So far everything has come apart with little effort. I was surprised due to the time it had sat. Hopefully it'll go back together the same way lol.

scottishsg said:

I have some Wurth 3000 that I was going to mix with the Honda Moly 60. Also I have Staburags grease for the input shaft. Should I not use that?

Click to expand...

There are proponents of both. Your choice.

Make sure to leave plenty of freeplay at the clutch lever. Check often and readjust when needed. Too little or no freeplay will wear clutch discs and kill throwout bearings.

Thanks again!

Now having problems getting the clutch cover off the dowels!!

Also was taping lightly on the cover with a small hammer trying to free it up a little. All of a sudden this little triangle of rubber appeared in the bottom of the bell housing? Any ideas as to what it may be??

That slides into a cutout in the upper left of the intermediate housing (bell housing) just to the right of the upper left tranny mounting bolt hole.

You're brilliant thanks! Right under the starter Any reason that cut out is there?

I'm at a stopping point now, can't get the clutch off. Will bring a lady's foot home from work tomorrow and give it a gentle pry.