The drivers side on my 99 F150 Supercab is sagginging in the rear. There is about 7/8" difference between the passenger and driver side height. The bottom leaf on the driver side has fanned out some. Could this be the cause since the third leaf is no longer providing full support or is the spring in need of replacement?

Do leaf springs need to be replaced in pairs? Are there any concerns with using springs from a salvage yard? My local yard has a leaf springs from a 2000 F150 7700 GVWR. Is there a difference in length between the 7700 and standard F150?

I have checked the shocks and they are fine. No oil leaking and when bounced the truck does rebounds just once and settles.

Also have a set of cheap set of Superior Automotive 1000 lb helper springs installed. The helper springs have made a significant difference in the stiffness of the right side and raised that side about 1". The left side was raised some but not quite as much as the right. When the rear is compressed on the left side, there is an apparent lack of stiffness compared to the right side.



As a side note, has any one noticed if their front end sat lower after installation of helper springs on the rear?