Can't figure out what is wrong with the drivetrain - Snowmobile Forum: Your #1 Snowmobile Forum

prankstar · 12-17-2005, 08:56 PM

I'm wondering if anybody can figure out what may be wrong with my buddies sled. He has a 2000 venture 500. When he starts rolling it makes a clunking noise in the drivetrain. Like something is catching then slipping again and again. He can get it up to high speed where it doesn't seem as bad. I think the problem is somewhere on the drive sprockets shaft that spins the track.

We tried to diagnose it. This is what we did: We took the belt off and noticed that his secondary clutch had a lot of play. We could turn by hand at least 30 to 40 degrees. Then we started to try and track down where the play was coming from. Took the secondary off and there is no play between that and the shaft. No play between the shaft and the top gear in the chaincase. No play in the chain, or from top gear to bottom gear. We didnt take the drive sprockets shaft out yet.

Does anybody know where it could be slipping.

Sorry for the lengthy post

Neatus · 12-17-2005, 09:32 PM

My SRX had a similar problem. I didn't know much about sleds back then but the guy who fixed it said it was a problem with the bearings.

prankstar · 12-18-2005, 03:11 AM

Did he take the drive sprocket shaft out?

**smallengineguy** · 12-18-2005, 07:13 AM

Is your track too loose, causing the track sprockets to slip?

Triple Triple · 12-19-2005, 12:46 PM

That happened on my srx, it ended up being a bolt on the right side of the sled(opposite side of the drive belt). It screwed into what i think was the chain case but I'm not quite sure. Anyway the bolt has a jamb nut on it and threaded itself out because of the vibration. I had to take all 3 pipes off and put blue locktight on it, and it took care of the slipping. Hope it's as simple for you.

tailtunz · 12-20-2005, 03:02 PM

This may sound too simple...but did you try using a different belt. Cause my sled was doing something similar...and I was almost positive there was something seriously wrong...with some clunking a chugging a low speed...but once I got moving...it was fine...strange. Well I tried my old belt...and it was fine !!! Easy fix. I was using a medium grade aftermarket belt...and well..I guess it wasnt the one for me. My old belt was a yamaha belt.

Just a thought?

Cheers