Suspension Lift Options 2000 Chevy 3500 8-lug

[zelseman]

My wife and I have been full-timing out of our 2000 Chevy Short Bus since April and have only recently picked up a 4runner to take to Baja for the Winter while we make plans for the bus. While driving the 4runner I have noticed that living out of a roof top tent is not nearly as comfortable as a queen sized bed with a heater and the 4runner is a lot of fun off-road as the bus is painful to say the least. This has led me to research upgrades for off road manners of the bus and allow better capability and comfort.

The bus:

It's time for some suspension upgrades. The suspension on the bus is completely stock and worn out. The front is a coil spring and the rear is leaf sprung. I know nothing else about the bus other than it having a 6.5L diesel and 8-lug wheels.
Upgrade plans include:

• Rear Sway Bar- The bus is already top heavy and rocks side to side on and off road and it is obvious that a rear sway bar is needed. This is the bar I am considering: https://www.sdtrucksprings.com/hellwig-7635-rear-sway-bar-1997-2017-g2500-g3500
• Rear Leaf Springs- I am hesitant to dump money into a helper spring, but an add a leaf seems like a decent solution to raise the truck a bit and support the weight of the conversion a bit better: https://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=1600
• Front Coil Springs- The front is quite bouncy and I figured if I am changing out the rear springs I might as well opt for new front springs as well: https://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=376
• Shocks- I have no idea how to go about ordering shocks for this thing. Am I better off replacing the springs then measuring the distance needed for the shocks and contacting Bilstein or FOX for a replacement?
• Rear Locker- Although not a suspension question, I have reached the conclusion by seeking advice and researching my options that a rear locker will allow traction in most situations and will be much simpler and affordable than swapping to a 4WD front axle. How do I determine what rear axle I have and which locker to select?

Thanks in advance for any assistance and like I said, my wife and I are in Baja for the winter so this will be Fall 2019 before anything happens, just trying to plan ahead.

And a picture of the 4Runner for kicks-

 

[Len.Barron]

I think the GMT-600 Vans share a lot of front suspension parts with the GMT-400 Pickups and SUVs...do a little searching on that and you may find some low cost solutions.

 

[bbbthreat]

https://expeditionportal.com/forum/...-info-thread-all-years-1500-2500-3500.172857/

 

[zelseman]

https://expeditionportal.com/forum/...-info-thread-all-years-1500-2500-3500.172857/

I think there is a difference between the vans and the cutaway chassis. I know for sure that the frame width is different.

Would it be crazy to pick up a used military axle from the old 6.5 Chevy military truck and swap everything to the bus? Or is that oversimplified?

 

[bbbthreat]

Despite the different size frames, the front suspension components should still be the same. Your van can utilize C3500 pickup components to achieve a front lift, assuming it is a 2000 3500 Express. Your generation of van shared front suspension components with C-body trucks - so that means coil spacers or spindles lifts should work for your application.

Cross reference with www.rockauto.com for parts fiches.

https://www.ebay.com/itm/4-5-LIFT-SPINDLES-WITH-BRAKE-LINES-FITS-88-00-CHEVY-C2500-C3500-2WD-8-LUG/264096453735?fits=Model:C3500&hash=item3d7d601467:g:WBIAAOSw0d1cEruq

Have you tried WeldTec with regards to your lift and shocks? They convert your front end to accept newer hub bodies off the Express 3500 (4500 assemblies are also a direct swap) assuming their lift spindles can hold the weight. Jeremy could at least point you in the right direction as far shocks are concerned.

If you do an add-a-leaf, make sure you get a long leaf. Shorter ones are cheaper, but they offer a stiffer ride. A better idea may be to go to onboard air and install air bags. It will help level out the vehicle, but will also get the added benefit of letting you air up/down your tires - a feature that could come in handy for your dually tire set up. Dually wheelbase's aren't known for their offroad prowess and whatever help you can give it, will go a long way. You may have to install a spacer between your wheels, depending on tire size and pressure, to allow your tires to flex without rubbing each other.

You should have a GM 14 Bolt, 10.5" ring gear in the rear end of your vehicle. That means there should be a ton of options available for gearing or a locker.
Rear differential identification

 

[Jo_Duval]

Weldtec is your best bet I’d say.

Boulderoffroad also offers lift kits for our vans/bus

 

[zelseman]

Despite the different size frames, the front suspension components should still be the same. Your van can utilize C3500 pickup components to achieve a front lift, assuming it is a 2000 3500 Express. Your generation of van shared front suspension components with C-body trucks - so that means coil spacers or spindles lifts should work for your application.

Have you tried WeldTec with regards to your lift and shocks? They convert your front end to accept newer hub bodies off the Express 3500 (4500 assemblies are also a direct swap) assuming their lift spindles can hold the weight. Jeremy could at least point you in the right direction as far shocks are concerned.

Jeremy basically said he couldn't help me without spending a ton of cash and converting everything to 2003+ which is half-way to a 4x4 SAS, and is too much money to spend on this rig. He also told me he doesn't have shocks that will work for my rig. Confirmed with FOX HQ that they don't have anything for me. I have since installed Bilstein in the rear and KYB HD's up front for the time being.

I have looked up the Moog spring chart and have debated on replacing my worn out front springs with stock height or +1 static height size and seeing what that does. A lot of the van RV's that I have researched (Roadtrek namely) have replaced the front springs with stock height Moog springs and it brought it back up to factory levels. My only concern is the rest of the front suspension/steerings seems like it would be effected by a 2" spring lift up front.

If you do an add-a-leaf, make sure you get a long leaf. Shorter ones are cheaper, but they offer a stiffer ride. A better idea may be to go to onboard air and install air bags. It will help level out the vehicle, but will also get the added benefit of letting you air up/down your tires - a feature that could come in handy for your dually tire set up. Dually wheelbase's aren't known for their offroad prowess and whatever help you can give it, will go a long way. You may have to install a spacer between your wheels, depending on tire size and pressure, to allow your tires to flex without rubbing each other.

You should have a GM 14 Bolt, 10.5" ring gear in the rear end of your vehicle. That means there should be a ton of options available for gearing or a locker.
Rear differential identification
View attachment 493178

I do have a 14 Bolt Full-float. Since this post I have installed a rear sway bar from Roadmaster and it helped with the sway of the vehicle a bit, but I am still getting some diving on the front and sway in the back. The 3 leaf pack that was stock is flat and pretty ineffective in most situations. I am leaning more toward a new leaf pack than an add a leaf. It seems like most of the RV's built on van chassis have 10-leaf packs that are substantial and the 3-leaf pack seems weak in comparison.

We have considered airbags as well, but it seems like a band-aid. If the springs are soft and not arched anymore, will air bags really help all that much. We already have an air compressor to air up and down. On board air would be nice eventually and we may still add air bags later on.

Weldtec is your best bet I’d say.

Boulderoffroad also offers lift kits for our vans/bus

Weldtec and Boulder both replied and said they essentially didn't have a solution for my rig.

 

[Umbrarian]

If you think the springs are shot, replace them completely. Adding an add-a-leaf is not the answer.

The one time I did it on a K5 Blazer, I got 2.5 inches of lift. In other words, the springs were sagging 2.5 inches and the factory replacement springs restored them to the original height.

 

[zelseman]

If you think the springs are shot, replace them completely. Adding an add-a-leaf is not the answer.

The one time I did it on a K5 Blazer, I got 2.5 inches of lift. In other words, the springs were sagging 2.5 inches and the factory replacement springs restored them to the original height.

That's what we are leaning to as well. We replaced the tired old leaf pack on our 4Runner last winter and the 2" lift springs added something closer to 5"!?

 

[Len.Barron]

restoring the original suspension height/stiffness probably all I would do, you've already got a big sail area, lifting it up to catch more wind is probably going to make you wish you had left it alone. If you decide to lift then you need it increase the spring rate (or install air bags) to counter that larger sail area otherwise you get blown all over the Hwy when you're up at speed...you'll also be giving away some mpg's with the taller profile..

 

[zelseman]

restoring the original suspension height/stiffness probably all I would do, you've already got a big sail area, lifting it up to catch more wind is probably going to make you wish you had left it alone. If you decide to lift then you need it increase the spring rate (or install air bags) to counter that larger sail area otherwise you get blown all over the Hwy when you're up at speed...you'll also be giving away some mpg's with the taller profile..

Are you suggesting that a 2-in lift above stock is going to create a noticeable sail effect beyond what it does right now? We have since ditched the boats up top so it's less sail like. My problems arise in the pot holes and undulating road where the front end dives then the rear end sways when I get moving. The sway bar helped, but it's still not right.

We are planning to replace worn steering/suspension components on the front end this Winter anyways, will likely replace front coil springs at the same time with +1 size up MOOG springs and replace the rear springs and add air bags. At that point if I am not happy, we will simply sell it and buy something more stable. Is there anything else in the front end that I need to watch as far as the geometry is concerned by adding 2" front and back? I assume that a competent alignment shop can align it after these changes?

 

[Len.Barron]

If you use blocks or spacers to lift it you are increasing the leverage against the spring (when compared to the same input as it had in stock configuration) it will drive like you have softer springs, and it will definitely make a(negative) difference, particularly at hwy speeds in the wind. Air bags in the rear will help quite a bit with stiffening it up and reducing sway. New springs up front along with new control arm bushings and maybe a heavier front sway bar (look for one off a box van with higher gvwr) would also likely help a bunch

 

[zelseman]

If you use blocks or spacers to lift it you are increasing the leverage against the spring (when compared to the same input as it had in stock configuration) it will drive like you have softer springs, and it will definitely make a(negative) difference, particularly at hwy speeds in the wind. Air bags in the rear will help quite a bit with stiffening it up and reducing sway. New springs up front along with new control arm bushings and maybe a heavier front sway bar (look for one off a box van with higher gvwr) would also likely help a bunch

I have gone back and forth on the rear lift an if I decide on lifting it would be via a more substantial custom leaf pack, not blocks. It has blocks currently (appear stock) and it is not a pleasant experience.

Air bags are likely happening this fall since we can install them anywhere without jacking it up and then a mild rebuild this winter when we can get it on stands in a heated shop with air tools.

The front sway bar is the same as the box truck as far as I can tell. It's the bigger of the two options that the parts store lists for bushings, so I assume it's the biggest one available. It's as thick as the Roadmaster in the rear.