Transmission problem
1991 Mazda Navajo 6 cyl Four Wheel Drive Manual 150000 miles

Hello-

My 4 wheel drive doesnt work 100% in this vehicle. when i press the button on the dash, reverse a little to engage, and then forward- it shakes and bucks a little, but 4 wheel drive is not engaged. i replaced the front hubs with used ones, but no changes.

anyone have any thoughts as to why the 4 wheel drive wont engage? any troubleshooting suggestions?

i heard from one person that i should clean the 4 wheel drive motor attached to the transfer case, anyone know if this is worthwhile? if so, what should i focus on while doing this?

thanks very much for any ideas.