jstone44720

Hello everyone. I am looking at swapping out my rear springs for softer models. My current springs are 3" wide, have 3 proper leaves and a large overload leaf. Online research tells me these are for models with a gvwr of greater than 8800lb, and that each spring will hold a bit over 3000lbs of weight (6000lbs for the pair). I am considering replacing them with the 2.5" wide version at holds about 1700 lbs per side. Would this be a meaningful reduction in stiffness//harshness? Currently bad highway joints are physically painful. I believe I would put spacers/heavy washers in the shackles or mounts to make them work with the narrower springs.


I am not worried about the loss of capacity - I have used my truck as a "truck" only rarely and don't tow. I should really be driving a passenger car, but the truck is paid for and the springs aren't that expensive.



Is this a reasonable plan?


Thanks all.

AlpineRAM

I'd start with removing one leaf (the lowest) from your existing package- should not cost a $...

Unless you hit the overloads- simple check is to put some putty on the contact patch of the overloads and go for a drive- squashed putty= weak springs, hitting the overloads.
No squashed putty- springs too harsh, test by removing one leaf..

oliver foster

I remove and modify stock leaf packs often on my projects.
Get a pair of new center pins and u/bolts in your hand before taking the leaf spring apart. I have had to cut a few center pins to take apart the springs and you don't want your truck down as you search for a set.

Also clamp the leaf spring pack BEFORE taking out that center pin so it doesn't "fluff up" when the pressure is released.

KATOOM

I'd get some smaller lighter capacity tires and air them to the lowest/safest pressure before I'd start tearing into the springs... Big tires and old tires will always make for a worse ride. Its simple to put on a new set of tires, but not so simple or appealing to change springs.

That goes for shocks too. If the shocks are toast or too stiff then the ride will be affected. Heck, you could even lay a few bags of cement on the back side of the bed to help soften the suspension. There's members who've done that looking for a softer ride.

Its easy to feel like you'd never sell your truck.....until you need to sell your truck. Then try explaining why you did what you did to the suspension, as the value plummets to most people looking for a "truck".

SIXSLUG

Trade it off for a half ton and some cash.....

u2slow

What's your tire pressure?

I run stock '95ish 2500 leafs (3" wide) with an extra leaf in there. I would say the ride is plush. I am running a shackle flip, but that shouldn't be a night & day difference from yours.

Pics here... Dana 80 swap - westcoast style - Dodge Ram, Ramcharger, Cummins, Jeep, Durango, Power Wagon, Trailduster, all Mopar Truck & SUV Owners. Dodgeram

jstone44720

The tires are new michelins, 235 ?65? 15 They are slightly taller and narrower than stock - basically dually tires. I run them at a high pressure, and will start there.

Katoom - if I hadn't just put the michelins on I would definitely look at lower capacity tires. Thanks for the word of caution regarding the next potential owner/ resale value. I have promised the truck to a friend when I am done with it, and he intends to use it for a fummins swap.

Shocks are heavy duty Bilsteins (blue and yellow?) with less than 10k miles on them.

Six Slug - yes, a half ton would be nice, and much closer to what I actually "need", and I have even been looking, though half heartedly. It is very hard to give up this truck.

Alpine, regarding the overloads: Completely unloaded, the front of the overload spring is effectively touching the lowest standard leaf. At the rear, there is approx. .75" of clearance between the tip of the overload and the first leaf. I have appropriated some of my son's play-doh for use as makeshift plasti-gauge, and will try it on the rear of the overload on the way home this evening.

Depending on which way the play-doh squish test goes, the DOR shackle flip looks promising.

Ballast for ride smoothing - I like it, and could easily do it in the interim. 200 lbs might be a good place to start. I have a winter weight plate I use sometimes that weighs 750 lbs, and it is a good bit too much for the purpose.

Thanks to all for sharing your ideas. I will post back in the morning with results from the play-doh test.

u2slow

Probably 235/85R16. I tend to run these at ~50psi unless I plan to carry a significant load. I prefer to run a 285/75R16 on my 2wd cummins trucks. 30-40 psi has been fine running empty.

AlpineRAM

Could you take a picture of your leaf springs?

Asymmetric distance to the overloads sounds a bit fishy... maybe a broken leaf letting you ride on the overloads all the time- or a stuck shackle pretensioning the spring in an unhealthy manner.

In a friend's 97 we removed one leaf and installed firestone air bags for use while loaded. The air bags go from the center of the axle up to the bump stops on the frame. It's very important to keep the air bags separate in terms of air pressure. (Do not use a T-fitting between them for inflation- get each one a hose and a shrader valve to adjust pressure)

jstone44720

I did the play-doh last nite on the trip home : the front of the overload was touching, so the squish test was only at the rear. It squished to about an 1/8" to 3/16" thick.

I checked, and then aired down the tires this morning, which helped take lots of harshness out. They had been between 74 to 78, as reported by a cheap autozone tire gauge. I put the fronts at 65 and the rears at 60 for the ride to work and it helped. I will make some more adjustments today - I will try to air them down as far as I can without harming the wear pattern.

Broken Spring : I will measure from ground to wheel well lip on both sides for starters, and see about getting the wheels off long enough to thoroughly examine the springs on both sides. Photos are possible - I will have to read up on how to post them though.

238/85/16 was the size - it made my speedo read correctly was the main reason for changing size.

Again, thanks all.

AlpineRAM

For measurements I'd suggest using the frame as a reference- but you need to be on completely flat ground with tire pressures equal on both wheels of all axles.
(Those beds were not too precise when new, and after all these years this could send you on a wild goose chase)

I'd clean the springs and take a look from inside the frame- if possible lifting first one and then the other rear wheel and verifying that the arc changes over all the spring and does not develop a kink.

For driving empty I use approx 44psi rear and 50psi front on the BF Goodrich MT in 255/85R16 - wear is good for an MT.

KATOOM

Yes, as you've noticed, tire air pressure will seriously affect ride quality. I dont run any more than 50 psi in the rear unless I'm hooked up to my 5th wheel. With a tire capacity of 3750 each, there's no need for almost 8000 lb of support back there when unloaded. Up front I'll run upwards of 60-65 psi depending, simply because the engine alone weighs over 1000 lbs.

nonrev

The wife used her truck (98.5 24v QCLB) as a pilot car for oversize loads, one of the first things we did was to remove the overload stops from the frame, also went to more of a stock shock, 265/75/16 tires @ 50lbs all the way around and the difference in ride quality was amazing. She has almost 500,000 on the truck now ( got it with just over 100,000)

Rare1

I deliberately bought a 2500 without camper suspension, see my sig. Very comfy with 50-60 psi in stock E-rate tires, flat air bags, and Rancho shocks set soft. Even better with a 400 lb topper. Then to carry a Lance camper it's a process: Air up to 80 psi. Inflate the bags until truck is level. Stiffen the shocks until it feels right. Still rides nice.

jstone44720

Over the past weeks I've been reducing the pressure in the rears - 50 to 52 PSI is treating me very nicely compared to how it was. Fronts are at 65 and will be dropping to 60 then 55 and see how it goes. Currently the front is harsher than the rear.
The current plan is to buy a decent 12v inflator and leave it behind the seat for if I actually need to haul anything.