Look under the lower dash by the transfer case shifter.
You will have to have it scanned for codes, check with your parts house. They may scan for you.
Yes.. I Have a 1990 F-150 4X4 and it is a 5-Speed Manual Transmission
Replacing Ball joints Check Related Links Below
this could be caused by a number of things,first check that shock absorbers are good. next check all ball joints and wheel bearings.then have king pins checked
4X4=12
Auto Zone will check your computer codes for FREE. It will actually tell you what you need to know.
Who cares
See link below.
The gear oil best suited for a 1991 4x4 is 75w-40. The best idea, however, is to check the owner's manual which will provide recommended products for the vehicle.
you can probably find a used step bumper at a wreckers shouldnt cost more than 100 bucks to buy
With electronic 4x4 there will be a rotary dial below the radio and to the left ( 2H 4H 4L ) With manual 4x4 there will be a selector lever on the transmission hump also , when the vehicle is first started , there will be 4x4 and LOW RANGE lights on momentarily in the gauge cluster in order to check that the bulbs work
See link.