I am getting ready to do my first clutch installation on my '77 R100/7. My recently purchased components (pressure plate, clutch disk, diaphragm spring and compression ring) have just arrived from EME. Up to this point I have replaced the rear main seal, flywheel O-ring, oil pump O-ring and flywheel bolts. I have new clutch bolts to use when installing the clutch components as well. My question is, is there any particular alignment needed between the new pressure plate and compression ring when I install them? I've read some articles stating such. Any help is appreciated.
J.T.
I’m about to do the same with my ‘78 R100, so watching to see what advice you get. I did mine 25 years ago, and my memory isn’t what it once was!
I don’t think there is any alignment or orientation required between the pressure plate and the compression ring. The clutch disk, of course, needs to be centered with a tool when the clutch is assembled. Also, the clutch disk faces a certain direction. The center hub protrudes more one direction vs the other. I can’t remember which side faces the transmission.
Thanks David. I appreciate the input. Yes, I do already have the clutch alignment tool. The side of the clutch disk with the small conical "dish" faces the transmission. Am beginning to wonder if the whole marking business applies to reusing the old compression ring and pressure plate. Can only assume they must establish some wear patterns through use and these patterns may need to be matched back up in order to prevent excessive wear of the new clutch disk.
I agonized over whether to just put the old clutch pack back in, since it measured 4.7mm thick. Snowbum recommends 4.5mm as the minimum wear limits. If this new one lasts 25 as it seems yours did, then I will be happy that I went ahead and replaced the whole thing.
• You need to chock the crankshaft BEFORE loosening any of the clutch pack or the internal crankshaft thrust washers will fall out.
• You have to reassemble the main cast parts the same way they came off. MARK ALL THE PARTS BEFORE DIS-ASSEMBLY. This affects the balance of the engine, thus the vibration you'll feel.
• You need to use an "alignment tool" to center the friction disk within the clutch pack before torqueing down the pressure plate. Otherwise the gearbox will not want to go back into place.
• Don't forget to "lube the splines".
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
@j-t-sutton yes, I believe you are correct. If you are reinstalling clutch parts you removed, you should mark them and return them to their original position (to preserve the balance). I’m going to send mine to Southland Clutch for refurbishment, and then reinstalling, so I’ll be marking mine.
Dave -
I know you already know this.... but if the parts are going away from your house, remember that while they are away they may be cleaned by media blast or chemical dip. Therefore, the "marking" you use should be more than a simple Sharpie or paint marker. You'll need something stamped into the metal or a tiny divot made by the point of a drill bit.
All the best.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Richard, thanks for your post. I am a relative newby here and there is one item from your post that I'm not quite sure about.
You need to chock the crankshaft BEFORE loosening any of the clutch pack or the internal crankshaft thrust washers will fall out.
On my '77 /7 the entire clutch pack assembly bolts directly to the flywheel. The flywheel itself is then connected to the back of the crankshaft by the 5 flywheel bolts. By removing just the clutch pack, I don't see how it would be possible for the crankshaft to move forward since it's still being held tight by the unloosened flywheel bolts. Prior to loosening the flywheel bolts, as part of replacing the rear main seal, I made sure to secure the front of the crank from moving and potentially having a thrush washer fall out of place. In doing some reading I believe the whole clutch setup was changed somewhere around '81, resulting in there no longer being a flywheel. Since both of my Airheads are '77s, I don't have any direct experience with this setup. Maybe that setup does requires such.
Also, all references to marking the compression ring and pressure plate seem to revolve around removing one previously installed on the bike with the intent of reinstalling those parts. Since I'm installing all new parts, is there no need to worry about such alignment? I've looked both of the new parts over several times and can't see any particular markings on them. I just don't want to get everything back together only to find out I have a balance and resulting vibration issue and have to remove it all and start over.
• When I go into this area ALL of the following gets done: oil pump o-ring, c/s main seal, clutch friction disc, splines lubed, new flywheel bolts, new drive shaft boot, and on and on. Some of that work necessitates removing the flywheel.
• If you are installing all new parts, then you'll be taking what you are handed.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Richard...sorry I asked.
Richard...sorry I asked.
Sorry, but I'm not following. Hope I haven't offended you.
The plain and simple is that it takes so long to get to that area, that it's not worth anyone's time to do a single task. Especially when you are doing this work on your own. So the full list of items needs to be completed each time, in order to maximize the time until the next entry into the area. "The plan" is to make it where this only needs doing every 6-8 years.
Stating it plainly, you'd feel like a fool if 2 weeks after completing this work, the 20 cent oil pump o-ring needed replacing. And especially so, if motor oil sprayed onto the new clutch friction plate requiring it's replacement a second time.
Don't ask me how I know this. ?
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
@j-t-sutton reading your original post, sounds like you have done everything correctly. I’m sure you have new driveshaft bolts as well. Happy riding!
I saved this picture from an online article looking at clutch replacement in a modern BMW boxer (RT, I believe). I said, “yikes!, I love my old airhead!”
The front of the crankshaft needs to be blocked with rearward force only for flywheel removal / refitting. Since you replaced oil pump seal and rear main seal which required removal of the flywheel, I assume this was done. If you were just working on the clutch pack and leaving the flywheel untouched then you wouldn't need to block the crankshaft.
You were wise to purchase all the components of the clutch pack. I tried to replace just the friction disk and reuse the old pressure plate and compression ring and ended up with terrible chattering due to the wear and incompatibility of the old parts with the new friction disk. I then had to tear down again and rebuild the clutch pack properly with new pressure plate and compression ring! The new pressure plate and compression ring I got from EME likewise were not marked at all for balancing so I just had to reassemble in random orientation and hope that the manufacturing process for the parts produced them fairly well balanced.
@4949
David,
Yep I have new driveshaft bolts too. I am going to go ahead and replace my transmission input seal, since it seems to be pretty grungy around the input shaft. Have the right moly grease to lube the splines as well. Am hoping to have the time to get it all back together tomorrow. Thanks for your help.
David,
Yes, I used an Allen socket in the alternator bolt and strapped in securely to the frame to make sure the crank didn't shift on me. At least that was the plan and the sincere hope. I think it worked just fine.
Thanks so much for your input about purchasing the whole clutch pack. Have to admit I've been a little worried that I may have spent money that didn't need to be done by not just replacing the clutch disk. Comforting to know you bought the same setup from EME and seem pleased with it. What model Airhead were working on?
Hoping to have the time to put it all back together tomorrow.
J.T. and David - I'd be interested to know what you think about your engines' vibration level after you're done installing the EME clutch parts that aren't marked for balancing / orientation. I know it's only subjective, but it seems my bike does vibrate a bit more than the previous original setup. That's at idle anyway in the driveway, I haven't taken it out on the road yet here in new england. One difference between my original clutch pack and the new EME components is the original had a wrought steel compression ring whereas the new EME is made from significantly beefier cast steel. I weighed the original and the new cast rings, without looking at my notes, I think the new cast compression ring was about a 1/2 pound heavier, that's significant in a rotating member.
My bike is a '72 R75/5.
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