I could use some advice on getting the box on my 1956 F-100 level.The right side is 5/8- 3/4" lower on the pass side. Can it be shimmed or is it an issue with the running boards also.Any help from those that know would be great.

 

 

Is it definately the bed or the cab?

 

I measured from the shop floor to the top rear of the box, cab is setting fine.

 

You can shim the bed, but it might be better to investigate a little further and determine why the bed is uneven, rather than throwing a band-aid on it without checking to see if something is broken. My 2c.

 

This is not a normal or common problem, there is something else wrong. Are you measuring the bed to the floor or to some other part of the truck? First block/shim the frame level front to back and side to side (check that the rear of the frame is level side to side when the front is level) then measure everything from the floor and/or check level. I expect you will find you have a twist in the frame, bed, worn/collapsed rear cab mounts, or sagged suspension.

 

Well I measured and put a level to everything. The font of the box is dead level. Rear shock perches measure out perfect. I think the issue is with the right rear leaf springs,blocking off the axle is the same height and there is no shackle adjustment so I'm thinking that I may have some leaf sag.The floor to frame is good but the floor to rear leaf shackles are off.

 

If the lean is in the suspension, it's not unusual for the driver's side suspension to sag more than the passenger side due to there being more weight being consistently carried on that side. Also you may have a cracked spring leaf and/or worn spring eye bushings and shackle pins on that side.

 

The hunt continues. Think I'll get the jack under the rig and see if I can make a discovery?This truck was my Grandads and given to me from my Uncle (who did the resto).He is 78 now and he may have had a heavy right foot.Truck is using the factory 393 rear end and he said that he wanted to replace it, so if I do not find the issue I may add to that leaf to get that level until it gets a 9" or 8.8.

 

Ten bucks says one of the bed mounting bolts is torqued more than the others. Loosen them all up just slightly and re-measure. Been there. Done that.

 

My F1 bed is crooked too. The cross members were all bent, cracked or broken. I welded and straightened as best as I could, but it's still not level. In my case, when I remove the bed for paint, I'm going to replace all the cross members with square tube.