My 4 wheel drive is not working correctly. When I switch to 4 wheel drive it doesn't go in. When I switch to 4 lock it goes into 4 lock. If I switch from 4 lock to 4 wheel it works. I remove the servo and it works perfectly. The linear gear moves freely in the differential. There are no worn teeth on either gear.
I am methodical about changing my differential oil. I change it way more often than is needed but I get into a lot mud so I thought it would best.
I am at a loss. Everything looks like it should be working perfectly. The only thing I can think of is that the servo is weak