Hey there everyone, working on my 99 500's tranny. The seals started leaking so I pulled it out and cracked the case to check on the bearings and the chains. Still plenty of life in the big chain but the reverse chain seems very loose. The one on my 06 also seemed loose but since it only had 600 miles on it I left it alone and just did the bad bearings. Are they loose by design, and is there any way to check how worn they are like you can a cam chain? All the transmission sections have is disassembly and assembly.

1999 Sportsman 509. wiseco 93mm forged piston. Moose gaskets. CRU aftermarket HO camshaft. new diaphragm and block. Summit water temp gauge. EPI clutch rebuild. custom spacers on both clutch springs. runnin Mobil 1 0W-40

 

The main drive chain has a spring loaded adjuster to keep the chain tight.Check that the adjuster isn't at the extent of it's travel or the main chain may need to be replaced. Reverse chains are a tad loose on these transmissions,but the easy way to tell is to pull on links and check for any give on the links. If in doubt replace it as it's not worth tearing back into the tranny for a little over 30 buck chain.

 

The main chain is fine, I was actually surprised since it has to have 5,800+ (hard) miles on it. The reverse chain seems to have more play in it at the links so I've ordered one. Thanks for the insight.

1999 Sportsman 509. wiseco 93mm forged piston. Moose gaskets. CRU aftermarket HO camshaft. new diaphragm and block. Summit water temp gauge. EPI clutch rebuild. custom spacers on both clutch springs. runnin Mobil 1 0W-40

 

The tensioner pawl and the nylon guide on the main drive chain keeps the chain tight and less stress/jerking is put on the chain when engaged. I guess Polaris decided the smaller reverse chain didn't need one,but the stress of reverse engagement on the already loose chain is what causes the stretching.I've had to replace reverse chains also without having to change the main drive chain.