Leaf Springs

I have a 2002 F-250 4x4 with 7.3

I have been trying to track down a noise for a year coming from the front end.

It occurs when I hit a large bump. It sounds like you are driving over wake up stripes on the side of the interstate and the sound continues until you either hit another large bump or slow down.

I replaced my shocks and the sound stopped for 2 months. I then replaced my worn out Sway bar end links and track bar bushings. I also replaced my bushings in the front leaf springs.

once I did all the work the sound became worse. Almost every bump I hit I would get this sound. It sounds like a leaf spring rattling. I noticed the leaf springs were seperating in front to the point of being able to stick a pencil between them.

I made some make shift clamps out off metal and glued rubber on one side of the metal and added a piece of rubber between the leaf springs.

This seems to have fixed the problem however I'm not 100 % because I have not got to drive it enough for a thorough test.

My truck has 149,000 miles on it. Do leaf springs go bad where they have to be replaced? Is this a common problem ? My springs almost look flat like there is no arch in them. As a matter of fact it looks like they are starting to sag so they arch the wrong way.

I do not want to waste money on a new set of springs if not needed and need some opinions here.

My truck is the super duty model that does not have coil springs.

Thank You