How do you change U-joints for 1990 Chevy pickup 4x4?

Answer 1

The U-joints in the 89-99 Chevy trucks are found in the driveshafts. The front axles do not have U-joints, they use CV jointed axle shafts.

You will need a socket set, a pair of needle nose pliers or snap ring pliers, a C-press or a large C-clamp.

U-joint on the differential end is attached to the yoke with a pair of caps. Each cap is held by two small bolts. Take out the bolts and remove the caps, the shaft will fall free of the yoke. The shaft can then be pulled from the transmission, the splined yoke will just come out if you pull.

The joints can have outer or inner snap rings holding them in, or a kind of glue. Squeeze (outer) or spread (inner) the rings with pliers and remove them from the grooves they ride in. Scrape off the glue as best you can. A propane torch might help soften the glue, but don't get too carried away with heating.

Then, use the C-press or the clamp and a large socket to push the joint to one side. You can then tilt it and pull it out. Put in the new one the same way.

Clean the yokes before putting it all back together. It's easy (and sometimes necessary) to pull off the joint caps, you don't want dirt getting into the bearings. Also, if you pull the caps off, be careful not to lose any of the tiny bearing rollers. It might be best to assemble the joints to the shaft over a light-colored rag or shop towel so that you can see any dropped pieces.

Also, be careful inserting splined yokes back into the tranny. There is a rubber seal that you can damage if you don't watch what you are doing, and this will cause the transmission to leak.