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I don't know if you have ever had the clutch hub out for inspection or not,
so we'll start there.
Remove the primary cover unless it's an open system and if it is, you have just saved some time. Remove the lock nut from the push adjusting screw [located in the center of thepressure plate]. Now place a flat washer [that is 1/8" thick, 1 3/4" diameter and3/8" hole] over the adjusting screw and replace the locknut. Tighten the locknut until the flat washer compresses the pressure plate and springs enough to free the three [or could be five if upgraded] clutch spring tension adjustment nuts. Then remove the three [or five] nuts.
You can now remove the pressure plate and springs as an assembly. With the pressure plate assembly removed, the clutch plates should slide freely from the clutch shell,or basket as it is often referred. IT IS ALWAYS GOOD PRACTICE WHEN REMOVING ANY CLUTCH PLATES TO MARK AND REINSTALL THEM EXACTLY IN THE SAME ORDER AND FACING THE SAME DIRECTION AS THEY WERE ORIGINALLY INSTALLED.
At this time inspect the steel drive plates fully for wear, flatness, and warpage. Also check the three buffer balls and springs that are riveted to the outside diameter of the steel drive plates. These buffer balls, or clutch anti-rattle [that is a fucking joke if you ride an open primary you know why I'm laughing] are not used on '81 and later steel drive plates. You should include checking the clutch shell keys riveted to the inside of the clutch basket for any signs of looseness and for groove wear. If these shell keys are grooved or badly worn, the clutch may not release properly and/or may drag. Also check the drive hub stubs and clutch hub pins to make sure they are tight, as well as straight. Similarly, the friction plates will drag and not release if they don't slide freely on the studs and pins.
If you only have a few hand tools this is about as far as you can go into the clutch basket, BUT if you encountered an abnormal amount of wear to the clutch pieces it is highly advisable to remove the clutch drum and hub for a closer inspection of the clutch hub friction liner and bearings.
Removing the compensating sprocket nut [1 3/4" or 1 1/2" depending on model]
the entire primary drive will slide off as a unit. [On chain drive remove
the adjuster now] This will expose the clutch hub assembly.
Check the bearing race inside the clutch shell for grooves or pits. Spin the clutch hub roller bearing assembly several times. It is sticks or feels rough, remove the clutchhub assembly [NUT HAS LEFT-HANDED THREAD]. If the races and bearings are pitted, REPLACE THEM!!! If you are lucky at this point, the clutch basket race and the hub race and bearings will only require some grease.
If the friction lining on the clutch hub is badly worn or glassed from grease thrown from the clutch hub bearing, replace it. You can buy replacement friction hug liner kits with all necessary rivets.
Let's hope you didn't go the lazy route and are now ready for reassembly. With the clutch hub nut torqued to 50-60 ft/lgs and the race and bearing greased [but not too damn much], install the clutch shell, primary chain and adjuster [or belt] and compensating sprocket [or pulley] as an assembly. Tighten the nut to 80-100 ft/lbs torque.
Starting with a friction disc first, then a steel drive plate. On 1980 and earlier models,make sure the side of the steel drive plate stamped "OUT" is facing you, and that you stagger the buffer balls in the clutch shell. Your last plate must be a friction plate or you goofed and must start over. This is because the pressure plate assembly presses directly against the first friction disc.
Now get the pressure plate assembly you laid aside about a six-pack ago. Because the pressure plate is subjected to the frictional heat of the clutch pack, it should be carefully checked for warpage and scoring. [If you use a straight edge instead of a flat surface [precision], be sure to check it from several different positions. You can almost count on having the clutch springs sacked out because of the springs closeness to the heat generated by the clutch. Doing service to the pressure plate assembly is fairly easy.
With the 1 3/4" diameter flat washer still behind the pushrod adjusting screw locknut, back out the push rod adjusting screw until it is flush with the inner surface of the pressure plate. Now remove the locknut and flat washer, the spring collar, and ten clutch springs. When replacing springs you should always measure the free length of all 10 springs. If they are not of equal length, the pressure plate will not release or engage the clutch pack evenly, causing both clutch slip and chattering. [But if you can find a cure for the chatter, I will buy you a bottle of JD]. Now might be a good time to install heavy duty springs because as the springs lose tension [cause by heat and normal use] heavier springs can be adjusted more times than stock springs.
Reassembly of the pressure plate is the same, and best done by fitting the pieces into the clutch shell. Simply place the pressure plate into the clutch shell, position the 10 springs over the clutch hub pins and studs, place the spring collar [cover] over the springs so the three [or five] studs line up with the three [or five] holes in the spring cover. Stud holes are arranged to that the cover will only fit one way. Now place the 1 3/4"flat washer over the adjusting screw, then the nut, and tighten the nut until the studs protrude through the cover. Install the three [or five] spring tension adjusting nuts. Remove the 1 3/4" flat washer and reinstall the push rod adjustment screw nut [FINGER TIGHT FOR NOW].
Adjust the pressure plate spring as follows. If using the longer '68 and later springs, draw down the three [or five] adjustment nuts evenly until the distance between the outside surface of the pressure plate and inner lip of the spring cover is exactly 1 1/32". Check this in several places. Using shorter heavy duty springs, the distance is 31/32", again check in several places.
To check pressure plate spring tension, place the tranny in gear and with the rear wheel off the ground, crank the engine over by hand with the rear wheel. DO NOT increase the spring tension any more than is necessary to make the clutch hold. In cases where your adjustment of spring tension is to an already in-service pressure plate, increase the tension on the stud nuts a half turn at a time until the clutch holds. If the used springs have to be adjusted so that the measured distance between the clutch pressure plate and spring cover is 7/8" or less, the clutch will probably not disengage because of spring coil bind.
Now for what you have been waiting for, but by now you know your clutch
inside and out.
TO ADJUST FOR PROPER CLUTCH PUSH ROD CLEARANCE, turn the push rod adjusting screw inward [clockwise] until contact is made with the pushrod, then back off the screw 1/8" turn and tighten the locknut. If adjusted properly, the hand lever should have approximately 1/4" freeplay before disengaging the clutch. In some instances, the variance in clutch pack thickness [worn plates vs. new plates] may require some readjustment of the cable adjuster to achieve proper hand lever free play.
For those just interested in servicing the pressure plate springs and push rod adjustment, the clutch springs can be removed and serviced through the inspection cover in the primary, which only require a couple of sockets, and a 1 3/4" flat washer.
I strongly recommend installing the Tamer kit and an aluminum pressure plate. Personally I think running an open primary with a belt is the way to go but to each their own.