hey got a quick question for you polaris guys. I just bought a 2000 scrambler 400 and it drives fine and goes into reverse fine as well, but when it starts moving in reverse it grinds. The grinding almost feels like slipping. I bought a manual for it but it really sucks and doesnt tell me anything about the tranny. Any tips?

 

I'm assuming your holding the override button, right???

 

check your fluid level also if its low it can make it grind.

 

I replaced the tranny fluid it came out looking good too. It grinds in reverse the same when i push the override button.

 

I have a 97 Sport 400L and the shifter fork is worn pretty bad and it allows the gear/dawgs to grind. A shifter fork for it cost around $120 not to mention about another $100 for the gears that are half worn out from the grinding.
You might want to check the linkage to make sure its allowing it to fully engage into gear.
I noticed it before i bought it , but like you i thought it was the belt slipping.