leaving for camping tommorrow have issue today with truck surging thought fuel and went under to blow back fuel tank sock and more searching i found bad u joint on transfer case side of shaft . like very wobbly.


i think it is also cause of vibration. do you drop whole shaft and the heat out old ujoint? how do new ones go in ? any help appreciated

I've always taken out the shaft to replace U joints. I always do both when one goes. You do have to melt out the injected plastic to get the joint out of the shaft. The new ones go in and are held in place with spring retainers in a groove at the outside of the bearing end caps.

There shouldn't be any injected plastic to melt out on the rear shaft in any of the 3/4 ton chevys. The joints just need to be "pressed" in and out. A good sized bench vise, a large ball peen hammer and an aluminum punch work great. Some guys like to use ball joint presses.

When changing U-joints, put a little extra grease in the cup and spread it over the needles with your finger( this does not apply to most sealed OEM joints as additional grease should not be added), this will lessen your chances of needles falling out of place during installation. Put a little lube ( motor oil, gear oil, anything slippery will do, make sure the cup is pressing in straight and it is not cocked. If you continue to apply pressure with whatever you are using for a press and the cup is cocked you will likely bend the yoke. If the cup is pressing in hard, give the opposite side of the yoke a firm swat with the hammer while pressure is still applied to the cap. DO NOT hit the weld or tube with the hammer. Make sure the snap rings are properly seated in the groove. If this sounds even remotely intimidating or you are worried, find someone with experience to help. A brand new U joint can and will fail quickly if not properly installed.