When 3900 sport is off and I turn wheels with hand, the single side wheel will NOT tu

[SunLover18]

And when I try to turn it by hand it feels weird and makes a strange noise but you can tell something is messed up. Where do I start?

 

[PoolGuy4Life]

Gear box, rebuild it with a gear kit for a 380/360.

And when I try to turn it by hand it feels weird and makes a strange noise but you can tell something is messed up. Where do I start?

 

[Njaneer]

Could be a gear, could be the ladder chain or sprocket is stripped or the chain is stretched. Is it under warranty? If so, take it to a authorized Polaris dealer for repair, if not DIY and remove the upper body and inspect it. If the ladder chain and sprocket are not stretched or stripped and the sound is coming inside the gearbox assy, you can either 1) buy a new gearbox assembly P/N 39-200 or tear it apart and replace the parts as required. Could be a worn out bearing as well.

You can see all the parts here:

https://www.polarispool.com/en/products/pressure/polaris-3900