You can change the spring with the clutch in the sled, but I find it much easier to remove the clutch and do it on a bench.
13/16" socket on the primary clutch bolt, strap wrench to hold clutch from spinning, remove primary clutch bolt. Clutch is a taper fit on the crank stub. You can either use a primary clutch puller (~$50) or a bolt that fits the threads inside the clutch w/ teflon tape on the threads and some water to hydraulic the clutch off. I've never done the hydraulic technique but I hear it works well.
With the clutch off the sled, remove the 6 cover bolts (either a 7/16" or 3/8" socket). I remove three of the bolts, then loosen each of the remaining 3 little by little. When the 3 bolts are nearly out, I put a knee on the cover to compress the spring down then finish removing the bolts.
Shimming the primary clutch spider for belt side clearance requires some specialty tools, and most suggest sending the clutch off (I recommend IndySpecialties, TOP notch work and great customer service). This can be done at home if you have/make your own tools, but the torque spec for the spider lock nut is around 250 ft lbs. Do a search in the clutching forum for P-85 shimming if you're interested. It is important to have the shimming done, so don't skip this. It will prolong the life of the crankshaft substantially, as will a good balance job.
There were two different secondaries on these sleds. A Team Industries TSS-98 or a Polaris button style. I am not familiar with the button style. For either one, to remove, use a 1/2" socket on the bolt that threads into the jackshaft, hold the brake lever to keep it from spinning as you loosen. The Team is pretty easy to service if you have a means to compress the spring and a good snap ring pliers to remove the snap ring that holds the roller assembly onto the shaft. The 8 helix bolts can be a b*&ch to remove, they like to get stuck and break torx bits. Heat helps here.
To clean the clutches, use hot soapy water and a scotchbrite type pad. This is another reason removing the clutches is nice, you can wash them thoroughly in the kitchen sink. Skip the brake clean, it gets into the pores of the aluminum.
Primary clutch bolt torque spec it 50ft lbs., but IndySpecialties told me: 70 ft lbs, put sled on stand, run the engine, engage primary clutch several times, shut engine off, retorque to 70 ft lbs, ride sled around shop/yard for a few minutes, retorque to 70 ft. lbs, repeat this until it stops taking torque. I trust IndyDan significantly more than Polaris. Make sure the crank stub and the clutch taper are polished, clean, and have no oil or anything on them before you mate the clutch to the crank!
There is a lot of info in the Clutching section too. Seen here:
http://www.snowestonline.com/forum/showthread.php?t=225971
