I had to do an axle swap for a friend of mine on his E150 van because going down the freeway the rearend would vibrate your teeth loose. I took out the old axle and noticed it had 4.11 in the old axle and the new one had 3.0 in it which will workout better for him since he doesn't pull a big trailer like the old owner of the van. but anyway I took the old 9" apart to see what might be wrong and it was only the outer bearings on the axle the carrier was fine. Now Igot to thinking I have a 1982 F150 4x4 with a 9" rearend with 33x12.5x15 tires on it along with 3.0 gears which kill my truck going up the mountains on the freeway and pulling my boat oh man you better pack a lunch my truck turns into a pig. I was debating just getting a set of stock rims and small tires and when I take out the boat I would have to swap out tires. Well not anymore I am going to install the 4.11 in my truck and now I just need to find a Dana 44 4.10 set of gears for the front end. but I think I got a good deal on this I got paid for the work and got a free 9" differential for my truck with the gears I need