The U-joints wiggle fine, not too loose. The carrier bearing rubber was worn out, and there is no clunking or play from the rear-end when put into gear or wear on the pinion. I change all the fluids with Mobil 1, rear-end every 60k, trans ever 45k and oil every 6k. The play does not feel from the rear-end as much as middle of the truck. I check the gears closely every time I open the pumpkin, and haven't seen any wear or cupped teeth. The pinion from the rear-end is tight. If it is the U-joints, I would still like to change it to a solid metal shaft, but would like to know from someone who has done this, what were the long term effects? MPG, ride, towing capacity, ect ect.