my adventure continues :pale: as i have now replaced the rear main seal on the 86 K100rs , installed the clutch housing etc and realized all that leaking oil got onto the friction plate and that spells replacement according to the manual.  a reminder that i'm a newbie to mechanical affairs and is why i didn't immediately realize i would prob need a new friction plate after discovering the mess.  
 
is the heavy duty / oil proof  friction plate from motobins, at nearly 3x the price, worth it? i know i could get two oem plates  for less than the "heavy duty one" but i thought if for whatever reason oil ends up past the rear main seal again the clutch would continue to work properly with the "oil proof". is that right?

 btw one of my reasons for inspecting the splines for lube and going in to replace the rear main seal was some erratic shifting issues, ending up in neutral at times , hard to get in gear, grinding noises, . so is it reasonable to suspect the oiled friction plate as part of these problems? the splines are all in good shape, although in need of lube. 

flip

if it took 20 something years for the rear seal to start leaking , then a fair bet would be that it wont happen again for a while ...if you have done a good job at replacing the seal this time around

I would hazard a guess that many would fall into the higher price friction plate out of fear that it might happen again .

but a gummy friction plate , along with poor spline lubrication would- might explain poor shifting characteristics

its a pity that the clutch plate spline material isn't rated for hardness across the brands eh ?

go with a reputable brand standard plate

just my 2 cents worth

Yes, I agree, Charlie, my standard plate has coped with pulling an outfit for well over 100K miles, many of them pulling a trailer loaded with my model traction engine, so I can't see the need for a 'heavy duty' plate, especially on a solo.



Paul.

ok thanks for the input, think i'll go with the cheaper generic and hope the rear main seal replacement keeps things dry.  . . 

 but wait maybe i should have consulted about the condition of the plate first after reading your comment Charlie about the plate being gummy? i might not call it gummy , the plate feels smooth, hard, and glazed , and you would need sandpaper to get some of the fibers raised. and elsewhere someone suggested those are indicators of a bad plate. so is a glazed looking plate normal or not? should it have some fuzz to it or feel somewhat soft ? 

i sprayed cleaner on it three times and wiped each time with a clean rag and it will still stain a rag with black residue.

that's the real issue

no matter what you do it will still bleed oil and slip ....when that happens it stresses out all the other bits with both the slippage and heat generated by it .

I think rick and a few others have found dished out thrust plate parts ....probably from similar and thickness issues

ok , looks as if i'll have to get a replacement. am curious to see how the shifting goes when it gets back together, if , that is . hah  hah . .

Check the pressure and fixed plates for being dished. Put a strait edge across the face and the inside edge may be down anything up to 2mm and if you put a good plate in it only bites on about 4mm on the outer rim of the plate and will slip badly. It happened to me with the K100 and K1100 and when I looked through my collection of clutches there was only one good set out of 5 or 6 lots. However I have put a clutch on a K75 back together with the dished plates and the friction plate that was worn to match and it has done well over 20K now.
If as Charlie said the plate has had oil on it and been heated (by a hot engine) then replace it you will never have success with it.

okay thanks Rick, thankfully they appear non dished.  i checked the inside of the pressure plate and fixed plate, the surface where the friction plate goes and rides against , with a straight edge from the outer to outer sides, and rotating the straight edge around to check various points,   and the inner sides are even with the outer sides, no slope towards the center.

hmmm, well i went backed and looked again and i did find one area on the fixed plate that was worn down maybe .5 mm but it appears that it was just in one spot. would that be enough of a concern?

Charlie has hit the nail on the head. If me, (which I did) i"d go for  a standard plate. I got an aftermarket one on mine when I rebuilt. 10000ks is early days of course but as long as I am not doing smokies or wheelstanding the bike I cant see the plate failing prior to normal wear and tear time frames

Flip2 wrote:hmmm, well i went backed and looked again and i did find one area on the fixed plate that was worn down maybe .5 mm but it appears that it was just in one spot. would that be enough of a concern?

It has probably had a hot spot at some time. More than likely it will go for a long time but if it were mine I would replace it as I would always be thinking about it.

The rear main seal is in front of the clutch housing (basket, whatever..) The notion the a leaky rear main can foul a clutch plate is lunacy.

Even if he clutch nut O-ring goes it still takes many thousands of miles for oil to foul the clutch plate.

maybe like this duck ?

The oil will pass under the pressure and fixed drive plate and spray out onto the inside of the housing but not directly into the clutch. However as Duck says it does eventually get into the clutch just by the fact of being in there with it but won't get in very quickly or directly from a leaking seal or O-ring.

since we are on the subject of the seal as well, should i have used loctite on the clutch nut? the manual didn't say to and i torqued it down properly to seat the ring and then loosened it and retorqued . would hate to buy another o ring and nut if it really needs to be done  but since it hasn't been put back together i guess i prob would. is the red mark on the nut , as in the picture above,  from the factory?  

also when i go to put the transmission back on to the engine should i tighten the transmission to the engine bolts first and then tighten the two frame to transmission bolts?

Flip2 wrote:since we are on the subject of the seal as well, should i have used loctite on the clutch nut? the manual didn't say to and i torqued it down properly to seat the ring and then loosened it and retorqued . would hate to buy another o ring and nut if it really needs to be done  but since it hasn't been put back together i guess i prob would. is the red mark on the nut , as in the picture above,  from the factory?  

also when i go to put the transmission back on to the engine should i tighten the transmission to the engine bolts first and then tighten the two frame to transmission bolts?

Haynes says to replace the nut and reckons it is a one time use but after lots of consulting with auto rebuilders etc they all said Loctite it so thats all I did for the nut. Not sure about the nut. Someone may have been there before you. Its not critical anyway as you are using torque settings.

The box should be fixed to the bell housing first and then the box to the frame but be careful.

You will need to centre the clutch plate (friction plate) on the housing.

I did mine by using the pushrod from the box and slipping the box in to position first with the clutch housing bolts still loose to centre the plate then removing the box real carefully and tightening up the clutch housing bolts. Make sure to lube the splines as well using some real good goo and also you will need to retighten the engine bolts ( all of them, ) in sequence, taking up the slack with shims on the final one or suffer the big vibrations through the frame

thanks for the info. i might try that method- slip the gearbox on to center it and then remove to tighten the bolts.  other members have  used magic markers to center the clutch, evidently.  hopefully , i can make some progress with the bike this week.

Hi there, regarding the plate centering procedure, I would not use the push rod, the magic marker does a much better work and is cheap. The only function of the centering procedure is to leave the plate´s hub axe on line with the gearbox´s axe for mounting purposes, once the gearbox is installed and the clutch engaged, the plate will self center on the gearbox input spline.
Best regards
JAP

japuentes wrote:Hi there, regarding the plate centering procedure, I would not use the push rod, the magic marker does a much better work and is cheap. The only function of the centering procedure is to leave the plate´s hub axe on line with the gearbox´s axe for mounting purposes, once the gearbox is installed and the clutch engaged, the plate will self center on the gearbox input spline.
Best regards
JAP

Sorry mate. I was just quoting Haynes Workshop owners manual, and what I did



He even goes on to give a diagram of how to build your own tool for the job if you so desired to

hope this helps.

PDF available of the manual if anyone needs it. PM me