Hi, my neighbor borrowed my zf and i think they tried to tow a stuck car with it, now i have a clunking sound from somwhere in the rear, the sound is not there when in neutral and seems to follow the speed of the wheels, same rythm in both high and low gear, not more than usual shavings in engineoil or reardifferentialoil. Anyone have an idea? Om running out of them.

[2015 Z Force 800 53/Trail EPS]

Inspect the belt and the clutches first. If all is well, assume it's probably not in the transmission...although it can't be ruled-out just yet. Assume its after so determine if front or rear then start at the wheels and work in, check all the lugs, brakes disks for rocks, bearings, then CV joints. If all is good there look for any oddities in the differential and gear case, then front driveline. 

Wow Marcus, that would be a sure sign of a bad neighbour. If this person borrowed your Zforce with the undisclosed intent to use it to try and pull out a stuck car, and gave it back obviously damaged from the abuse he'd put it through, well that's a whole new level of untrustworthy entitled ... I'll stop there.

I'd try to prop the rear up with jackstands so the back wheels can turn free and then start checking from there forward, maybe with someone's help. Not to turn the wheels fast but just so you can watch that the rear axles are turning without bumping around. Good luck.

In neighbors defence it was his teenage son who did it and the father is willing to pay for the damage, im only trying to even out the amount of payment needed
I have checked brakes, and have disconnected the driveshaft to the front but the sound doesent dissapear, I have also dissconekted the shaft thats between front and rear driveshaft in the gearbox, an with one end off i thought it was a little to much movement, but i dont know how much would be ok, the gears looked ok what i could see tough. Btw excuse my English, not my first language but hope you can understand.

A video of the distribution box (not really sure if its the right name of it) with what i think maybe a little too much movement.

[2015 Z Force 800 53/Trail EPS]

That seems excessive and the splines look rounded off.

That seems excessive and the splines look rounded off.

Ditto on that. There must be another bearing behind that one ball race and that would be a whole lot of clunking around loose. I tried to make sense of the parts blow-up for that model on Alpha Sports but I couldn't.
https://alpha-sports.com/cfmoto_parts.htm
Your english is fine. Sorry I can't be more help.

I didnt find the blow up either, to bad the blow ups was way better than the one i found, yes its another ball bearing att the rear ( Ive dissadmbled the front one) but it seems i need to tear down all of the rear to gett the bearing out, so i shall do that now.
Do you guys think the cf bearings are ok or should i buy skf instead?

[2015 Z Force 800 53/Trail EPS]

My rule of thumb- if any Chinese-made parts can be replaced with anything better quality, it should be done. However even cheap Chinese bearings usually last pretty well when run submerged in lubricant so..my gut says if all this is because of bearings, how does that happen with one instance of pulling another vehicle? And how does some slightly loose bearing make this sound? Seems something else is happening here..or maybe there is more to the story the neighbor gave. Stripped splines maybe?