The Stovebolt Site Forums The Shop Area Driveline 57 3200 helper springs / airbags?

I’ve had the rear of my 57 3200 sink a little too far when trying to haul moderate loads. I have new springs coming, but as I intend to use this truck to occasionally tow a trailer and carry some load, I want to ensure it will not sink to the tires. I’m looking at either airbags or helper springs, and am interested in anyone’s experiences and examples of what best to buy for the easiest fit. I only just learned about helper springs and these seem like a good idea to avoid the need for air to adjust the ride height. Not sure if they effect the ride otherwise. Also curious on what ones could fit, as searching for an older truck obviously brings up zero options.

Any type of helper spring will increase the ride stiffness under all conditions.

There are a least 3 types of helper springs I have seen in use.

One is a coil spring that fits over the shock absorber. The kit will include 2 pair of saddle type clamps that fit around the upper and lower portions of the body of the shock. Those springs require clearance around the full length of the shock body.

There are also kits that include some type of mounting plates and brackets to add a coil spring between the axle and the frame.

There are leaf spring helper kits that clamp to the existing leaf springs.

These kits could also increase empty ride height if they are installed with some pre-load.

Overload springs are probably available that don't engage until the springs compress somewhat. I have overloads on my F250 that work that way. So they don't affect the ride until the suspension compresses enough so the ends of the overloads hit the brackets attached to the frame, totally separate from the main springs. The same type were standard equipment on some AD series big bolt trucks

They would be quite a bit more difficult to install than air bags. If you're looking for simple install, air bags would be your best choice IMO. The pressure can be adjusted for the load, so if you're unloaded with them aired up to minimum pressure, they wouldn't affect the ride significantly. But like you say, a specific air bag kit for an old truck would be hard to find, and would have to be adapted.

What Kevin said. I installed factory overloads on my 3600. They work Great for loads. The down side is the flatbed on my truck is just heavy enough to cause the overloads to engage frequently when on rough potholed roads, riding like the proverbial log wagon. The wife's living quarters horse trailer and Lance cabover camper hauling 2500 Ram has air bags. They're great, except one has started leaking down and I've been too cheap/lazy to swap it out.

One alternative I'm considering on the wife's truck and that would be a good option for yours Trebin is Timbren or SumoSprings Airless Air Bags

A lot of folks hauling cabover campers (bed weights of 2,500lbs to 4,500lbs are common) perfer the overloads systems above to air bags. Zero maintenance being the big plus.

Of course you could cancel your new springs that are on the way and have a spring shop build a set of springs for your particular situation (with the higher loads mentioned in mind) according to other members here, not expensive at all.

Good Luck,

RonR

Some years back I bought my daily driver. 1998 C3500. The P.O. went for the custom lowered look. He did that by torching the front springs and removing most of the leaves in the rear. I wanted an actual truck to use. So, i found new front springs (not easy.) And I air bagged the rear. It worked fine for hauling fifth wheels and such. After a while you deal with leaks, etc. I finally got tired of the ol' seasick, sway from side to side motion the bags gave me. The way it's plumbed, if your loaded, leaning to one side, the air goes to the unloaded side. Unless you have a side to side switch of some sort, there is no way to control that with a single pump or fill point. I found some low mile, original spring packs with overloads, and got rid of the bags. Much better ride now!!

thanks for the info everyone.

Your first springs were probably way too soft with less than the stock number of leaves. Air bags are really only to adjust ride height. Mine are plumbed individually with individual fill points, so there's no air transfer between them and no sway. But of course I still have the stock springs with overload leave that engage on suspension compression. I do have to adjust them each time my load changes, but that's not a big deal - 3 or 4 times a year.

Ok, I have some time now. About to head outside and start on the spring replacement on the truck. The new springs arrived (ordered the posies super slide), so I'll see how it sits and fairs once they go in. Following that, I'll add some air bags as needed. And yes, I'll plumb them independently (I do have bags on a sprinter van, but they came with it and I was just hoping someone had the model number of a set that required the least mod's).

Now, being new at this I am having to research how to replace these springs! Not an easy thing to find. I have replaced them on other cars before but honestly when I jacked up the truck last night and took a look (and sprayed some PB Blaster to be ready for today), I was confused when I couldnt see an obvious bolt to undo on the front of the springs. I finally found one video showing the retaining bolt. It was a short video, so I'm sure I'll find some issues. Its a step side so space seems limited to push a pin out. Ive worked on an old mustang a lot, and there are so many videos and info on how to do anything, including spring replacement. Not so much for the 50's trucks. I am most likely over thinking it, but I only have today to get this done and try to be prepared to avoid issues...

Thanks again for the help guys!
Dave.

Correct. The bags were just a stop-gap. Originally, they were plumbed separately with 2 schrader's mounted in the bumper.. Then I installed the pump in the engine compartment and adjustment valve in my cab. No real way to separate them then.