I have a 1986 f150 4x4 I want to change my u-joints in the front diff. ttb what holds them in and how do I remove the old ones

 

Where to start!. You can do both sides at the same time, or 1 side at a time. Remove the tire/wheel, locking hub assembly, the hub/rotor (must have the correct spindle nut socket) and remove the spindle bolts and the spindle itself. On the passenger side, you nust remove the outer band on the dust boot near the differential before removing the axle. Now you can pull the axles out. The u-joints should be removed with a press. If you don't have access to one, you can rent a u-joint press from most tool rental facilities. If you can't find a press, do what 90% of us do, and beat them out with a hammer and an old socket (remember to remove the retaining clips first). The new u-joints can be installed with a hammer, if you're very careful not to dislodge the needle bearings in the cups. This is the readers digest (shortened) version, most experienced shadetree mechanics can perform this in a few hours. The novice better plan on a whole weekend.