rear lift springs for towing (+airhelpers?)

[mini_mull]

OK, I sold my '87 1/2ton burb, and am now planning the buildup for my '91 V2500 burb. The ride is incredibly stiff (I think one of the POs put add a leafs and made it worse), so instead of keeping the 3/4ton springs and doing a ORD shackle flip or blocks, I'd like to replace the rear springs with 4" TC rear springs. I'm worried that this will affect my towing capacity though, so I thought I'd plan on adding rear air lift helpers, these Air Lift Super Duty Air Springs. Will they help enough to make up the difference between the 3/4ton springs and the TC springs? Do I need the air springs at all? Will the air bags effect off road flex if they're aired down? I plan on hauling a loaded heavy toy hauler in the future (around 9K), so I don't want to do anything now that will make that difficult/impossible then. Thanks for any and all info.

 

[Bob87Burb]

I'm running into the same problem right now with my 1500. The rear lift springs apparently are a softer rate, to compensate for the increased arch, and supposedly end up at the same load capacity as stock. I think the engineer's abacus was out of whack when he designed these springs. If I put a weekend load of camping gear in the back, and load up the family, it sags quite a bit. Add on the car trailer, and it just gets worse.

In my case, I'm planning to add the air bags you've linked. I don't tow that much, and when I do it's not that much weight. I also don't take the truck on trails, because we have none up here, so I don't care about limiting flex. From the looks of the bags and brackets though, they will limit flex in extreme situations. Eventually, the bag will bottom out before the bumpstop will.

I've done a little research, because I'm so unhappy with the rear springs. Apparently Procomp makes a spring (also in Summit Racing) that will lift, give a comfortable ride, and actually increase load capacity (of the spring that is, not the truck). They're about $110 per spring, not bad at all. Perhaps calling Procomp's tech line with your question is in order.

 

[Bob87Burb]

Just an update on this, for anyone looking. After some research (shoulda done that before, huh?), I've found that my Rough Country rear springs don't have the flat overload spring, nor are they the correct amount of leaves. Almost every other spring I've looked at has the flat overload spring, and 6 leaves. I even called ORD (really helpful, polite people!), and was told every spring that they were looking at had the overload and six leaves.

So, I'm going to call Rough Country tomorrow and ask them if these springs are made incorrectly, or if this is their intention. I'm hoping they're made incorrectly, and I can get correct springs from them, so I don't have to spend any more money on this.

 

[mini_mull]

Thanks for the update, Bob. Let us know what they say.

 

[afroman006]

It seems like the airbags would severely limit droop. What I am planning on doing on my DD k3500 is adding a set of on top of the spring pack overloads off a dually. I know its on a DD but it might be worth considering.

 

[dhcomp]

THere has got to be a way to not attach the bottom of the air bag and just setup a sort of pocket for it to rest in, so when the springs are at ride height the bags just touch, but then it would allow the springs to droop independent of the bags.


Someone should talk to Jason, before he decided to stop DDing the crewcab, he was planning on adding an airbag overload on his triangulated 4link in teh rear so he coudl still tow with it.

 

[Bob87Burb]

This is actually a good idea. Maybe modify/make a bracket so that it can be disconnected from the leaf end, but still connected when you need it to be.

 

[mini_mull]

Interesting idea. Wish I had a pair in front of me to play around with and figure it out. You do have to install the spacers for lifted vehicles in between the bags and the bottom bracket, I wonder if a disconnect could be fabbed up using the spacer.

 

[dhcomp]

I'm not even sure you'd need a disconnect....as long as the bags rested on the springs at ride height.

 

[cybrfire]

You'd have to rig up manual controls for the air bags. Most of the air bag systems I've seen use a mechanical linkage (lever with linkage frame to axle)to maintain ride height. If that were disabled I would think you could end up with the potential over inflating and blowing a bag out.

 

[Bob87Burb]

I'm pretty sure the airbags in question are the manual type, not the automatic leveling type. At least that's what I was talking about.

For the disconnect, between the spacer and bracket, how about using some tubing, welded onto the brackets and spacers, and making a hinge type joint? Then, you could use a clevis pin to hold both parts together.