I have an '02 F350 CC, 4x, diesel with a 6" DR lift. The lift was done in March '06. In Feb '07 the bottom leaf on the left rear pack fell out (on the freeway). Not a fun way to experience quadro-steer. The lift installer (HTW) was able to warrant a replacement pack after giving me some hassle. Unfortunately, this new pack caused the bed to sit higher on that side than the right side that had already begun to de-arc over the past year. I have tolerated the 1"-1-1/4" difference.
Two days ago, the second leaf of the rear right side pack fell out. Fortunately I was on service streets, turned a corner and heard the leaf rubbing against the tire. But I am still missing the very bottom leaf. Of course this resulted in the entire pack becoming loose. I could move both U-bolts around by hand.
It appears the bolt that locks the leaf spring bundle together and inserts into the small hole on top of the axle has snapped off.
I never heard any clunking sounds. the u-bolts on the other side are torqued tight. Never taken off-road. Daily driver with 1200-1500lbs in the payload at all times. Occasional towing of <4000lbs. I am light on the throttle.

What are the possible causes?
Axel wrap, too much torque (4.55 ratio in diff), not enough torque on the u-bolts, what else???

What are the solutions?
I think DR offers a lifetime warranty. I plan on investigating this tomorrow. If I get new spring packs every year no big deal, but I am more concerned about having an accident because a spring breaks loose again at 70mph.

 

if u lost 1" of lift due to sag in under 1 year then i suspect that kit must be pretty low quality...

maybe the pinch bolt they use to assemble the spring pack isnt high enuf quality or worse yet the bolt was used to squeeze the pack together during assembly..which is a no no.. that bolt is only meant to be tightened after the spring pack is fully compressed..

hard to say what might have caused it... do u have stacked blocks on the rear end by chance ???

 

Thanks for your quick response.
The kit is from Donahoe Racing and uses Deaver springs. I thought these were top of the line. Maybe I am wrong. Don't know about the assembly process, but I do feel the pinch bolt is too small. Looks like a 5/16". If I get a new pack, I would like to remove that bolt, drill out the hole to accomodate a high grade 5/8" bolt. Is this possible?
I do not have any blocks. This also means I lost the use of the bumper stop and overload spring.

 

Deaver is top of the line, but I agree the rest of the process is in question. I bet they are also re-using old u-bolts too. that is a no no.

 

Donahoe (now Icon) stopped using Deaver springs 1-2 years ago, they make their own now and they seem to be high quality. I'm guessing your u-bolts weren't tight enough causing extra stress in the middle of the spring pack.

 

Thanks for the responses. Today's update: I went to Icon, Cartmanea is correct. They stopped using Deaver because they were too soft. I saw their spring pack and it did look like each leaf was thicker than the Deavers. They suggested a u-bolt torque problem and questioned if the original torquing was done with the springs compressed, ie: off the lift. I don't know. Then I went to Deaver, Jeff was great to deal with, in less than one hour he had my pack rebuilt. Put in a larger pinch bolt but said that was not the problem. Agreed it was improper torque on u-bolts. Since they both need to be done (I took off the left side tonight and it is broken as well) I am going back tomorrow, they will add a leaf to give me a full 6" in rear without a block (I carry a lot of tools and this will level the bed), new bushings and new u-bolts. Total cost $260. Plus, they will retorque everything after I assemble. He suggested torquing every other oil change! How come that is not necessary with OEM springs?
As a side note. Jeff had mentioned to me that Donahoe has not purchased from them in 2 years.

 

u should really only have to recheck the bolts a couple of times... after the first few weeks.. then maybe a couple of months later...

after that they should be fully seated and shouldnt back off...

but its never really a bad idea to check all ur trucks important fasteners from time to time...

 

I agree, re-check after a few hundred miles then again in a couple of months, after that forget about it. you should be good. Just make sure they are tq to spec the first time!

 

Most all-spring kits will settle 1/2"-1". It is typical and to be expected.

As for the OP's U-Bolts, I have not installed any on my Super Duty, but when I purchased new (made-to-fit, my spec's) U-Bolts when I owned an '81 Chevy I was instructed by the spring shop to install and torque them down then take a hand maul and hit them as hard as I could all around the axle. Then re-torque. Check them periodically over the next few weeks.