Big Thank-you!

B

bobkandren

New member
A week or so ago I posted a message in the Technical forum regarding disassembly of the primary drive on my '82 Jota which had sat, unridden, for about a dozen years. When trying to re-activate the bike, I was unable to disengage the clutch and thought that the clutch plates were locked/glued together from sitting so long. I first contacted Paul LeClair, whom I hadn't spoken to in many years. He gave me great advice as to how to get things apart, which I followed successfully to the point where it was time to remove the clutch drum. That would not budge. The splines on the drum were "glued" to the tips of the friction plates. No heat or tapping with a plastic mallet would help. HTH, from Australia, mentioned that he'd used a piece of bar stock to make a puller, with 2 holes drilled through it. The holes line up with 2 of the threaded holes on the "posts" which face out from the drum and support the cush rubbers. Then, holding the piece of bar stock against the transmission main shaft. he put 2 bolts through the holes and screwed them in to the holes in the posts to pull off the drum. To be able to spread the force more evenly, I used a 5" by 5" by 3/16" piece of steel and drilled 8 holes in it that lined up with the post holes. Also I'm using steel bolts screwed into alloy holes and figured there would be less chance of stripping any threads. Anyway, with some tapping, it worked and sure enough, the clutch plates were well stuck together. I had to pry them apart with a screwdriver. After much wire brushing with solvents, and with new friction plates, I started the reassembly. Getting the drum back on was an awful job as the tips of the friction plates must be PERFECTLY lined up to match the splines on the drum. I cheated by using a fine file to slightly bevel the outer edges of the drum splines. Then with the clutch lever zip tied to the handlebar, with much wiggling, tapping, and cursing, I got the drum on. Next was getting the primary chain on. I'd not removed the crankshaft sprocket during disassembly so getting that chain on was also a challenge. It can be done, though, by first fitting the chain to the crank sprocket, then carefully. levering the clutch sprocket onto the drum. So mission accomplished and I want to thank Paul and HTH for their help. Bob Andren
 
Good work Bob, and you obviously proceeded very gently with the 8 hole version of the puller. Nice to read about someone taking the time to think about the job rather than going at it in an impatient and ham-fisted way.

Incidentally, it wasn't someone called HTH that gave you the advice. It was Steve B (forum name breganzane).
The HTH at the end of his post was simply internet shorthand for "hope this helps". Evidently it did!

Cheers,
Cam
 
Oh, and i always just fit the clutch screws (an IIRC maybe just 2 or 4 of them) in a few threads then us a steel ruler to get the splines lined up enough to enable the drum to be tapped on gently. It eventually bottoms out on the bolts you've not threaded in all the ay, but by then it's easy to align the last few plates.
 
Rather than a steel ruler, I find something that'll contact the clutch plate teeth on both sides works best because it'll move any misaligned plates in either direction. Something like a small Philips screwdriver shaft pressed down into the groove will align them perfectly, as long as you get it perpendicular to the plates. Then the drum should slide straight on. If it hangs up somewhere, a quick pull on the clutch lever and a bit of jiggling of the drum will get it home.
 
I have a couple of weak springs of the same dimension as the proper ones to temporarily fit and line them up as Cam does with a thin screwdriver shaft. Even barely on the thread with two clutch springs I can't move the plates.
 
You must log in or register to reply here.
Back
Top