Hi everyone,
I I just bought a 1993 Yamaha big Bear 350. I got at home and went for a test run and got it stuck in the mud in the back 40, as far as I know it's supposed to be a full-time 4 wheel drive but the front tires were not turning. The front drive shaft was turning but was not getting power to the wheels. Does anybody have suggestions?

 

Splines gone on front coupling, if all the shaft, including UJ is spinning but front has no drive, it is the coupling on the nose of the diff, but usually is further back. Jack front up, put rear brake on, and spin wheels by hand, watching what does go round on prop shaft and what doesn't, where the two join, is the spline that has failed. Just possible to be a faulty diff or a CV drive shaft spline, but usually prop shaft.

 

Okay, so I did what you said and the front left wheel is spinning freely without turning anything The right wheel catches like it's supposed to so I'm guessing that this blinds in the outer wheel on the left side has stripped. Now I know what to look for thank you for your help merryman👍

 

Unusual, as the nut holding the splines tight is also holding the wheel bearings tight, so you would expect a wobbly front wheel for a long time before the splines let go. Anyway you have narrowed it down to LH front hub and/or CV driveshaft.