Iv got an 01' 500 rubicon and im havin some trouble w/ the 4-wheel drive, i just got it, it came w/ a 4-2-4 selecter and i thought that the front wheels wernt workin cuz of that, but the driveshaft locks in and the front tires dont turn even when the atv is off the ground, if u have any ideas or tips i would be thankful for ur help, this isnt my 1st atv rebuild, i built a 96' honda 4x4 from scratch so i should know what ur talkin about, thanks

 

Can you see the shaft turning? When you say "locked in" is the 4-2-4 handle pushed in or pulled out? Out and locked is 2wd. Push the center button to engage 4wd.

 

I'm not sure I understand what is locking in? Is it just the handle or the actual driveshaft? When I put my 424 on we had to adjust the handle to make it engage. But yours isn't letting it go into 4 wheel drive. I'm still betting its just an adjustment in the handle.

 

sounds like the coupler in front of the motor, the splines are gone.