I have a 2001 Polaris Trailboss 325. Recently had a chain go bad and had to ride on it for a day, because of that it tore up both the front and back sprocket. Since, I have replaced the chain, swing arm bushings, and both sprockets. Still, when I give the four wheeler a lot of gas or a quick start the rear end makes a grinding noise and doesn't engage well. It does the same thing when on a hill, just grinds and doesn't engage well. Does this sound like a messed up gear in the transmission? Everything on the back axle is replaced and new. My next step is to replace the transmission fluid and look for medal shards. Thank you for your time.

 

Probably the internal silent chain has stretched and jumping teeth under a load. Common problem on this models as well as others. Item #38.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse Lot of work just to tear the gear case out and split it for this 38 buck chain,but I've done a bunch of them. Always replace the seals also.

 

Thank you sir. I will bust it open and check if the chain is stretched. Manual says 8 pitches can't be longer then 3.0904".

 

If you split the gear case always replace the chain plus check for any wear on shift forks,gear engagement dogs,etc..

 

The problem arose out of nowhere, could riding on a bad chain have hurt the internals of the transmission?

 

Chain stretch mainly just happens over time and you may not be aware of it.Pulling loads,jumping can cause this to happen quicker,but just like an external chain they do wear and stretch over time. Even if you're not hard on it or no abuse.

 

Thats why they don't use chain drive anymore. Shaft drive is basically maintenance free. I will never own another chain drive atv again in my life.

 

Chains are still in the gear cases though,can't do with out them. Hated the old 3 chain outer systems on awd drive machines because of maintenance,but efficient way of getting power to the ground.Now you just have to deal with prop shaft u joints along with cv joints.

 

Though they're much more reliable in the gear cases than using for the final drive to the rear wheels. I guess it was a cheaper way to do it too. Less power loss with a chain but then you have to deal with the chain, hoping it doesn't stretch or break or get caught on something etc. I had a Scrambler 500 before and the chain was a constant pain to deal with. I guess the Sportsman 500 was the first to offer shaft drive by Polaris. Obviously most sport quads still use chain drive but I have no interest buying one of those either. I'm in favor of eliminating things that require extra maintenance and chain drive on a utility quad falls into that category.

 

A guy at work thought chain drive was better because he could fix a broken chain with a piece of fence wire. Huh? I told him drive shafts don't break so you don't have to worry about fixing it in the field in the first place. He still thought chain drive was better but I don't miss dealing with one. If chains were better than drive shafts they'd put them on cars and trucks too.