U Joints are that terrible. They'll make you think the rear end's going to fall out from under though.
Get under the truck and push up and down back and forth to see if there is any slack. If there's any at all change them. Your stock u joints won't have grease fittings. The aftermarket ones should tho.
Ok thanks. I just want to try to do as much work on this truck myself and hopefully have it for a few good years to come. PS Thank you for the Welcomes and it probably won't be my last question on this forum. This F150 is all new to me.
Also how do I know what my rear end ratio is? I checked the sticker inside the door but didn't see anything or better yet didn't understand what the codes were.
