Two problems related to axle shaft seal have been reported for the 1999 Ford F-150. The most recently reported issues are listed below.
I own a 1999 Ford F-150. Twice since I bought it, there have been problems with the rear axle. One axle and bearings have been replaced. The other side is now doing the same thing. Other owners have told me they have had similar problems, sometimes both bearings going together or separately. It may appear that this is a factory defect in the axle or bearings. Vehicle has less than 80,000 miles.
We purchased this truck in oct 1999 new, we have had it in the shop 4 times for the brake problem. It first started out with the brakes locking up when it was damp out, they could not find a problem at that time . The next time they said it was the axel seal leaking. On July 11, 02 they said it was the brake shoes , which with only 35838 miles on the truck how could that be . The brake shoes was replaced at that time. Now today I was going down the road and the back rear brake started growling, so I stopped to see what the problem was , I removed the back tire and removed back hub and found pin to wheel cylinder laying in the hub. I called a wrecker to come and get me and my truck , went to dealer where I purchased it and stayed there just about all day . Thank you very much for hearing my complaint.