Rear End Vibration on "98 F-150

[shnoz1984]

Hello to everyone.

I have a problem with a vibration in the rear end of my truck. At first I figured it was an unbalanced wheel and never took it in since I was getting new tires in a month or so anyways. Well now I have the new tires and its still there.

It usually occurs at about 60-75 MPH. The weird thing is, its not all that noticeable until I'm going against the wind or have a cross wind. Like the other day I was going head-on into the wind and it was horrible.

Any help would be appreciated. I'm going to have a friend of mine look at it next week and see what he thinks but any advice would be appreciated.

Thanks.

[Whiteghost]

Bent rim?

Also do a search on this site for shimmy shake vibration 1998. You should be able to pull up lots of old posts on this same subject. Most people were complaining right after they bought their trucks. Looks like a common problem for 1998s.

I have the same thing in my 1998 F150 5.4L, auto, 8' bed, Reg. Cab, 3.55LS. Let us know if you figure it out.

[longjohnsilver]

My 98 has the vibration from 35 to 45 mph. I've replaced shocks, rearend fluid, rebuilt and balanced driveshaft, re-balanced tires. Recently soneone suggested worn out or broken leaf springs. Also broken trans or engine mounts. There's been tons of suggestions from weak COP's to rear brakes being to tight. Once, I had all the weight taken off the rear springs and set back down (crane magnet lifted the bed when removing cast iron scrap from the bed) and the vibration was gone but returned in about three days. I'm suspecting the rear springs are bad.