I have been working on this 81 Shovel for the past year and every time I think I'm close to finishing it, something new pops up. I have the clutch together, and I was going to adjust the Pressure Plate springs,, only problem is that the pressure plate is not stock. So it makes doing the measurement a problem. The pressure plate is a tapered conical one, so I can't take a measurement between the plate back and the spring plate. Does anyone know the thickness of a stock plate,, from the friction surface to the surface that the springs rest against. I need to find this out so I can get measurement from there to the spring plate and make the proper adjustment. I really don't want to have to order another Pressure Plate. The thickness of the Pressure Plate is 15/16th,, from the friction surface to the surface that the springs rest on. .470 I know the stock plate is flat, with spokes. I'm looking for the thickness from the friction surface to the surface the springs rest,, it would probably be approx 1/8". Any help would be appreciated,, thanks.

 

This is the plate that I have,,, http://www.jpcycles.com/product/6100035
This is the stock one,, http://www.jpcycles.com/product/6300001
As you can see, the one I have is substantially thicker,,

 

Determine the stud thread pitch so you will know how far the nut travels in one turn.
Put the springs in and run the nut down to finger tight. Turn the nut enough turns to compress the spring to the proper height.

Threads per inch devided by 1 will be how far the nut travels per turn.

Or if there is enough room next to the spring, mark a popsicle stick to the correct height and draw down the nut till the spring reaches the mark.

 

What I'm really looking for is the thickness of a stock pressure (release) plate. The book says there should be 1 1/32" between the lip of the spring plate and the face of the pressure plate. The problem I'm having is I have an aftermarket tapered aluminum plate. I believe a stock one is 1/8" thick where the springs contact the plate. I think I might have figured a way to establish this by taking the thickness of my plate 15/32" and subtracting 1/8",, which leaves 11/32" which I subtracted from the required 1 1/32", leaving11/16",,, which should be the new required distance between the spring plate and pressure plate surface. I just need to have the 1/8" stock PP verified to be sure,,, I'll try the Popsicle thing too. ;-)

 

I just spoke to JP Cycle,, the guy pretty much thought I was over thinking the problem. Me too! I think I have it pretty close,, Hand Grenades, Horse Shoes and Clutches,,

 

Dug out my old clutch assembly. The pressure plate is .093" thick and the spring retainer is .093" thick.

The studs are 5/16-24. 1/24 = .042. Each full turn of the nut will compress the spring .042".

Compress the spring ~.941". .941/.042 = 22.4 full turns. Use a speed handle with the crank up to 12:00 position. Count the turns each time the crank comes up to the 12:00 position.

 

Hey, Thanks AJ,, thats close enough to 1/8,, maybe 3/32. The math that I did will work, I'll just plug your number into it and go from there. I've been sweating the details way too much on this,, I just figured that if I've spent as much as I have, it would be better to get it as close as possible. I went thru this on the spacer behind the compensating sprocket shaft. I measured front and back so many times,, it drove me nuts. I know its supposed to be within .030, and I kept coming up with .021,, I ended up putting it together without a spacer and the primary chain is within .007, front to back. Close enough I reckon. When I get done it's going to be a pretty much brand new 81,, I had a 73 Super Glide and a 74 FLH back in the day,, bunch of other bikes. Now a 94 Ultra and my Home Rolled 81 Shovel. It took 62 years, but I think I'm Happy now,,,