I'm new and have read alot of helpful posts about common problems but have not seen one for my problem. I just bought a 400 xplorer 4x4 and every now and then when i try to shift into high or low it grinds. I can put in reverse and then back into high or low and it works fine.

 

The trany gears are all chewed up. Try to completely stop to shift it from now on. Change the tranny fluid a lot also to clean out the shavings accumulating probably.

 

some times if its idled to high as well or if you put it gear slow.

 

The main reasons for grinding going into gear is 1. the bell crank on the tranny is worn or stripped
2. idle is too high
3. shift fork is worn
4. rod is out of adjustment