Second time this has happened and I wonder how many others have had this problem, and how you handled it.

02 F350 PS DRW long bed with service bodiy and hoist mounted on service body and 129,000 miles on it. The right rear leaf spring perch, the rearmost one is broken again and the truck has fallen down to where the truckbed is resting on the end of the leaf spring. There is a big protrusion in the floor of the bed where the sheetmetal is deformed upward. The rivets that hold the perch to the frame rails broke some time ago and we replaced them with grade 8 bolts and new perches. Now the bolts are sheared off and the perch is broken again too. The truck weighs in at 12,300 lbs and the max GVW is 12,500 lbs.

I guess this time we will have to unload all my tools and parts and remove the bed to modify the works. I don't want to have to do this again!

 

In the FWIW category, bolts are meant to be used for compression and not for shear. If I had something the factory steel rivets sheared off, I certainly would have upgraded to bolts at least two (1/16s) sizes bigger then the rivets.

It sounds like you are using either 3/8 or 1/2 bolts when the app. might call for close to 5/8 or 3/4. What you have to do is make sure just the shoulder of the bolt (no threads) is engaged in the hole and it should be so tight that you literally have to lightly pound the shoulders in with a hammer. Any slop will be the end of the bolt eventually.

Plus, on any bolt you have to use a torque wrench, if you are just guessing on the torque the joint is prone to fail. Especially on the larger ones which will require 140- 250+ foot pounds.

If it was my truck, what I would do is grab a bracket from a heavier duty truck, say F-450 - F-600 and use that. Or (having a lack of excellent welding skills and big welders) have someone cut a bracket from rect. tubing that is thick walled, around 3/8, then build support into it (tri-angled brackets) so it does not twist on the outside where it is not supported from the factory. Hard to explain without drawing it, but, basically making it enforced double shear instead of single.

Not recommending it since you have already had breakage, but, what many people do is build such beefy shackles that they would never break and then they weld them to the frame. The only problem is when the frame cracks instead under excessive twisting loads.

> The truck weighs in at 12,300 lbs and the max GVW is 12,500 lbs.

That is on road GVW, if you are taking the truck off road or off paved surfaces you pretty much can cut the safe GVW in 1/2. Sort of like a 2 1/2 ton army truck. That is what it is rated off road, on road it actually is 5 tons.

How much do you lift with the hoist? Once you load the truck, is it over the GVW, and is what you loaded all on the right hand spring? Do you have outriggers to use with the hoist so all the weight is not put on the right hand spring perch while loading?From experience most people install hoists on the right hand corner which can really overload the right hand suspension.

I know you do not have access to the scales, but, sometimes if you weight the truck on each corner you will find one corner (mostly because of the utility body and a huge generator/welder) has put most of the body weight one of corner.

In the FWIW category, most of the weight is usually on the right rear wheel when braking and turning, so if you can, it usually is best to put most of the off-weight stuff on the driver's side or to move the hoist to the left.

 

Beef up the spring pearches and use 4, 1" bolts.

 

Thanks thesproket and rebocardo for your input. Went to Ford yesterday and bought a new perch and attachment hardware. I was surprised to see the holes in the new perch are only 7/16" diameter and the hardware is 3/8" bolts with nuts captive in a bracket. Seems kinda small to me. The spring shop is going to drill them out to 1/2" and use grade 8 bolts plus weld a triangulating gusset in place.

Looked at a perch for an F 450 and it was too large to attach and the spring connects differently. It also costs $140 more

I do go off-road occasionally, chasing oil rigs down, but I don't race. I take it easy because I don't want my tools jumping up and changing places on me. I also have my tools on the left side of the truck and the lighter parts and such on the right side along with the hoist just to keep the truck balanced out.

My hydraulic clutch linkage went south today also. Just finished installing it. It was a piece of cake except for removing the push-rod from the master cyl. Had to end up cutting it in two and replacing it with a new one. Always hate working under the dash!