Q for the engineers, F-700 light leaf spring mods ok?

[Mekanic]

I have a slight delima, I am wanting to drop the ride height about a inch to level the vehicle AND I'm hoping to soften the ride slightly.
The truck has a 10K rated front axle and springs with 9 leafs(4 inches wide) on each side.
Current weight on the front axle is 5400 lbs and this is without the trailer hooked to the back of the truck. (it has plenty of tounge weight for stability, look in the bottom 2 pics)
(Total Truck weight now is 13,600 lbs with 100 gallons of fuel. Truck GVW is 32,700 lbs.)
What I am thinking of doing is cutting the ends off the bottom two leafs on both sides with a cut off wheel. I feel with the weight so low compared to the capicity of the springs that is what is making is ride so harsh.
this pic is stock height. I did remove some 2.5 iron blocks to drop it some but its just not quite level.

with blocks removed, everything else stock

Truck hooked to Trailer.



does this sound like a acceptable way to reduce the spring rate?

[VanDiemen23]

It looks to me like the problem isn't too much front but not enough rear. You have the teeter-totter effect going on because of all that rear overhang plus the hitch weight.

[Mekanic]

Originally Posted by VanDiemen23

It looks to me like the problem isn't too much front but not enough rear. You have the teeter-totter effect going on because of all that rear overhang plus the hitch weight.

That not quite it either. No matter where I put the Jeep on the trailer the hitch only drops 1/2 inch.
(Back of the truck weighs 8100 and has the a 22K axle and springs)
I have thought about getting a air ride axle from a OTR truck and placing about a foot rearward of where that old axle is.

[VanDiemen23]

Why not start by taking 2 or 3 leafs out of the front then? It will have the same effect and is reversible if you don't get the results you are looking for.

[Mekanic]

Originally Posted by VanDiemen23

Why not start by taking 2 or 3 leafs out of the front then? It will have the same effect and is reversible if you don't get the results you are looking for.

I have to buy new bolts and then cut them to length. I've allready done that once.
I'm getting a new set of steer tires friday, and they will be slightly shorter. THe height will pribibly be fine at that point. I was just thinking about keeping the pck height the same and dropping the spring rate.

[EngineerMike]

W/9 leaves, and the vehicle weights you quote (i'm assuming that's w/the new house on it), I see no harm in chopping the lower spring. The # of springs is probably not proportional, i.e. frequently the bottom spring is way fatter, so you won't be taking out 1/9th of the spring but somewhat more than that. Which sounds like a decent move in the right direction to me. Nice solution IMO, to using a way heavier truck than needed.

I'd make sure to stop short of cutting thru the lower leaf or you'll make what's called a "notch" in the next spring somewhat massively reducing its safe carrying capacity. You may decide that one gets a chop also after doing the lower, but IIWM&I was thinking that, I'd chop the 2nd one further from the axle. Each time, I'd leave a teeny bit of metal using the cutoff wheel, then hand saw what's left w/a hacksaw till I could bend/fatigue the scrap piece out.

Then dress the sharp corners, the scalp you save may be your own.
And BTW don't you need some boxes below floor line for basement storage?

[AirLift]

I believe you mentioned air bags, but have you considered pulling some of the rear leafs and adding air? This would let you keep most if not all of your load capacity but only when needed.

[Mekanic]

Originally Posted by AirLift

I believe you mentioned air bags, but have you considered pulling some of the rear leafs and adding air? This would let you keep most if not all of your load capacity but only when needed.

I'm quite familar with air lift products. I do like them. I sold them 20 years a go when I worked at Jegs in Columbus Ohio.
The way the springs are set up now the thickness of the springs(10 leafs in normal pack + 4 more in overloads EACH SIDE) are what keeps the axle from wrap up. So I really can't do much with the stock spring or there be negative results like wheel hop if i lock it up under braking. For this reason I am looking for a complete air ride axle from a class 8 truck. This will also give a shocks as well. (mine also has NO rear shocks at all from the factory)