Local Leaf Spring Work and a Q about Full and Partial Wrap

[deminimis]

Well, I've been back and forth on the whole Deavers thing. No doubt, they kick butt. However, that's a lot of coin for new leaf packs (then you have the old ones laying around). Decided I'm going to try and have a spring shop in Portland re-work my springs. Although they haven't seen my rig yet, I got a ball park plan and price over the phone. Recurving springs and adding a couple of leaves to each pack, on vehicle, will run approx $400 per axle. For those higher math challenged, that works out to aprox $800 total. I'm shooting for getting over there to have it done this Thursday if my schedule allows (its a 200+ mile round trip for me). The $1500 savings will help offset the cost of new shocks (Bilstein 7100 or Fox). Could save even more if I removed the springs myself, but seperated my shoulder (dirt bike), so I'm kinda worthless for a couple of months when it comes to heavy work.

For the spring knowledable, do you know why Sportsmobile chose a partial military wrap instead of a full military wrap? I understand a full wrap will keep the spring curve (perhaps indefinately). My guess is a partial wrap allows the spring to better keep its curve (than non-wrap), but allow for a plusher ride. I just don't know. Think I might prefer a full wrap as don't want to mess with springs again, but just don't know the pros/cons of doing it, so any real world experience (SMB or whatever) would be appreciated.

[jage]

I always assumed that full wrap was most expensive/hardest to make, partial wrap was less costly etc. My spring shop looked at the Deavers and said something about double overwrap or something. I saw similar springs for heavy duty trucks on their shelves, albiet fewer and thicker leaves.

[deminimis]

Found out the wrap refers to the spring wrapping around the eye:

With military-wraps, the second leaf plate wraps around the spring eye (called the main leaf) to form a double-wrap. This design element transmits less stress to the main leaf during extreme articulation. It also lessens the odds of spring separation in case of main leaf failure, and provides greater strength, support, and durability as a whole.


Yea, I want that!

[Ford_6L_E350]

I'm not sure there is a full military wrap. How would you make it? Wrap both springs together? And how could you replace either leaf?

I thought the name was 'partial wrap' because it only wraps part way around the spring eyes. It happens the military insists on this feature, hence the name.

I always thought the purpose of the partial wrap was to have support if the main leaf fails. Picture the stock spring and now think about the spring fracturing near the end!!!! Total loss of support!. The partial wrap will hold the weight of the van if that should happen.

Feel free to correct me if I'm wrong in my beliefs - sometimes I think we only learn by making mistakes (and I've learned alot that way) and I can learn when I'm corrected.

Mike

[deminimis]

Torque spring added (I'm not adding a torque spring, but a good illustration)


With full military and torque spring added


Just went outside and checked. Sure enough, on my SMB, the second leaf only wraps half-way around the eye (comes from underneath and stops at the leading edge of the eye).

[jage]

Here are the Deavers:

[Ford_6L_E350]

I see by the one picture, the 2nd eye is wrapped around the first during forming.

What is the advantage of the full wrap? You can see it will hold the spring/axle in place even when the adjacent wheel is pulled off the ground. Anything else?

Mike

[deminimis]

As stated above, from Peterson's site: "This design element transmits less stress to the main leaf during extreme articulation. It also lessens the odds of spring separation in case of main leaf failure, and provides greater strength, support, and durability as a whole."

I should clarify, the red hot spring pic'd above is a torque spring, not something we'd be using (not recommended for V-8s and bigger). However, that pic illustrates the wrap/formation well.


Jage, those are purdy. Those rears are damn impressive. 12 leaves on the rear? Did I count that right? How they treat'n you so far?

Just heard back from my relatively local spring shop. If I want to change to a full military wrap, I'm looking at two days in the shop, not one. Humm, let's pencil this out. Diesel for 200+ miles, sleeping on a buddy's couch during a stay-over, sushi, more sushi, drinks, more drinks, more drinks, sushi left-overs, hang-over, two days out of the office. Might be a push for me.

[jage]

Originally Posted by deminimis

Jage, those are purdy. Those rears are damn impressive. 12 leaves on the rear? Did I count that right? How they treat'n you so far?

Ehh. The ride in the front is awesome, but the back pushes and my wife won't drive the van anymore. They're still settling, but flat towing I had 3 near death experiences on the way out and only one on the way back- if that was due to conditions or further breaking-in I'm not sure.

[Ford_6L_E350]

Originally Posted by jage

They're still settling, but flat towing I had 3 near death experiences on the way out and only one on the way back- if that was due to conditions or further breaking-in I'm not sure.

What kind of near death experience? The only one I've had with my SMB was when the front axle track bar came loose and I got the dreaded 'Death Wobble'. That should not happen with a leaf spring front end, but it can with a coil spring front end like mine.

Near death is never fun.

Mike