Chevy Suspension Upgrade Complete

[CaDreamin]

My suspension work on my van is complete and I have to say I am very happy with the results. Its is a 2004 Chevy Express 3500 Roadtrek 190 Popular.

Bilstien shocks all around
AirLift LoadLifter 5000 with internal bump stops
Onboard compressor with wireless control
Moog 81004 front coils
Alignment

Heights before/after upgrade

Wheels are measured from the top of the wheel wheel to the ground going straight through the center of the wheel. The “dump” measurement was from the bottom of the ground effects at the dump valve to the ground. This point is more-or-less level of the bottom of the plumbing and easy to measure. It is the area most prone to scraping.


Before

33.25 front
6.5 dump
35 rear

After

100 lbs (max)
Front 35.5
Dump 10
Rear 38

40 lbs
Front 35.5
9.5 dump
36.5 rear

5 lbs (min)
Front 35.5
9.25 dump
35.75 rear


Scraping

Vastly improved. I went over several steep driveways at local businesses without incident. This includes ones where other vehicles had left a large number of scars on the pavement. I did not use the trick of going at the entrance at an angle to reduce scraping, I went straight in. I was unable to find a driveway that produced any scraping at all. This was my primary reason for doing the upgrade and I would rate this as an unqualified success.

Roll

Very substantially improved. There is a bump I travel over regularly at an angle. This bump would cause the vehicle to lurch violently. I can now take it at a moderate speed without problems. Also the motion is “once and done”. This is true of all suspension movements. If it moves, it moves only once.

General Ride Stability and Feel

Much nicer. I had some minor wandering at highway speeds, it felt a little “drifty.” This seems to be gone. The van feels lot more “planted” on the road. More under control. I would suspect that this is because the suspension is keeping the van level. Before it would lean to the outside of turns but it no longer does this. Some people have worried that raising the center of gravity of the van would make it feel like it was tipping over but with the reduced tendency of the van to lean to the outside of turns it actually feels more stable.

Smoothness/Harshness

Somewhat better. You still feel every bump in the road. The bumps lack a lot of the jarring quality that they had before. It’s like getting hit with a rubber hammer instead of a ball peen hammer. I don’t think that 10 miles of washboard road would be very pleasant. It rides like what it is, a work truck. I think that the harshness is better but since I am focusing so much on the bumps it’s really hard to say. I would like to get more “cush” in the front, I am hoping that as the springs settle things will be less harsh.

Many thanks to all for the excellent information.

(I gave the alignment guy Booster’s numbers to use as a guideline but told him to use his judgement. He commented that the numbers were on the mark.)

[CaDreamin]

Costs

Moog 81004 Front coil Springs
Rock Auto
192.79 plus 12.99 to ship

SDTruckSprings
2 ea. 2003-2013 Chevy Express 3500, 2500 (Over 7,300 GVW) - Heavy Duty Bilstein Shock Absorber (Front) $186.90
2 ea. Bilstein 24-221948 46mm Monotube Shock Absorber $211.90
1 ea. 1998-2012 Chevrolet G-3500 Class "C" - "Load Lifter 5000 ULTIMATE" Air Springs w/ Jounce [REAR] $335.08
1 ea. Air Lift Wireless Air - Remote Air Compressor System (Control Two Springs Independently) $379.95


$1,113.84 Sub-Total:
Free shipping
-$40.00 Discount Coupon:
$1,073.84 Total:

I know the shocks are a little high but but I liked the price on the air bags and they confirmed with me over the phone that they had the shocks in stock and could ship right away. No one else seemed to actually have them. Well they didn’t have them either — nobody that I could find actually had them — and it was 20 days between ordering and the arrival of the shocks.

I had a mechanic neighbor who owed me some favors so I got him to help me do the airbags, compressor and rear shocks . The coil springs, front shock install and the alignment came to $330.

[peteco]

Originally Posted by CaDreamin

Costs
The coil springs, front shock install and the alignment came to $330.

I did the springs and shock myself. Alignment is usually about $100. Shocks are easy. But I would gladly pay $230 for the spring install. I'm fairly handy but those heavy springs were kinda scary to install.

[booster]

Fantastic to see another happy camper from the modifications for height!


It appears that the current list of parts and specs is working well, with good results, so the changes are getting to be much more common.


The heights listed for after lifting are right at what we would expect to see.

[User1213]

Before & after pics?

[Deano]

See my post in "Tweaks, Mods & Projects"

[CaDreamin]

Here’s few ‘after’ pics. Really didn’t take any ‘befores.’

[CaDreamin]

These photos show the location of the compressor. It was not hard to find a place for it

This photo is taken from the passenger side. The compressor is mounted inboard on one of the driver’s side rails. In the photo the front of the van is to your right.

I drew a red line in the photo. It marks the front of the fiberglass drain pan where it meets the cab section.

We were unable to figure a way to mount the bags as delivered. There were welded in place. In other photos I have seen a bracket but we did not have one.

The backup schrader valves were mounted inside the shower compartment. The tees in the air lines that go to the compressor are right behind the shower compartment. This arrangement let us get it done without needing additional air tubing.

[J__T]

I have a 3500 Expressed based Roadtrek and a Sprinter-Based van. My wife rides in the back on the couch and always complained about being thrown around. The fix in the Sprinter was easy: we installed VBAir's air suspension system. I have not seen anything for the 3500. How bumpy is it in the back for someone riding on the sofa after your upgrades? Thanks in advance!

[booster]

Others can speak for their impressions, as all of this is very much an individual perception.


We have had 3 different variations of the rear suspension in our 07 Roadtrek 190.


All stock gave the ride everyone sees, not too bad on small bumps, but punishing and noisy on big bumps.


All stock but with the addition of air bags to lift the rear a bit off the huge overload spring leafs. Decent on the small and up into most of the normal bumps, but still harsh and noisy on the bigger bumps.


Non stock in that we removed the overload leafs from the rear springs to keep them from hitting on big bumps, and changed the airbags to ones that have an internal urethane bump stop in them. This change smoothed out all bumps quite well for us, and we are quite happy with it. The disclaimer is that we are the only ones that have done this change to date, so unproven in the mainstream.

[J__T]

You are the first mention of a compressor-based bag system for the 3500 Express that I have seen. It sounds like exactly what I have been looking for. Thanks much for sharing.

[markf57]

Originally Posted by CaDreamin

Costs

1 ea. 1998-2012 Chevrolet G-3500 Class "C" - "Load Lifter 5000 ULTIMATE" Air Springs w/ Jounce [REAR] $335.08

What part number did you use? Based on a search, it sounds like you used 88245.

When I search the airlift site, I find that 88205 fits the Express 3500.

Maybe that's why you had to weld the bracket?

I'm trying to get up the nerve to try this install myself as the shop I checked in Boulder wants a fortune to install them.

[booster]

Originally Posted by markf57

What part number did you use? Based on a search, it sounds like you used 88245.

When I search the airlift site, I find that 88205 fits the Express 3500.

Maybe that's why you had to weld the bracket?

I'm trying to get up the nerve to try this install myself as the shop I checked in Boulder wants a fortune to install them.

Airlift has had a bit of confusion in their specs when we tried to use their part finder. For a long time they listed the 88245 for the "cargo van" and the 88205 for the "passenger van". The vans are different in the rear frame rails which are C channel for the 88245 and box frame for the 88205. We all think that Roadtreks are cargo vans that are converted, but the frames are boxed, so the 88205 is the correct part number for them, which is how Airlift now lists them for all 3500 full body vans. They now show the 88245 for the cutaways with the C channel frames.


There have been lots of people get the C channel ones by mistake and have to alter things a bit to get the mounts to fit.

[Bjones7788]

Some time ago there were quite a few posts on suspension modifications to gain better ground clearance for Chevy based Roadtreks. I think there were concerns expressed by some customers about taller front coil springs available aftermarket developing a lateral bowing out in the middle of the spring height.
Please keep us informed if this issue materializes over time with the recent suspension modification. Thanks for the detailed measurements. Every Chevy Roadtrek I have looked at has shown at least some evidence of ground clearance damage underneath. Same with Airstream Avenues by the way on Chevy chassis.
BJ 2004 & 2013 Roadtrek 190 Populars
Drjones7788@gmail.com
443 480 1023

[booster]

The springs that had bowing issues were test ones that were made at lower springrate and longer freelength than the Moog 81004 or some of the other stock length springs. Our early Tufftruck springs are essentially the same as the 81004 and have been in for something like 7 years without issue.


I don't think anyone has had bowing issues with the stock length and 1.03 or 1.06" diameter wire, which are what essentially everyone has, except for a few Erb springs that are 1" wire and about 1/4" longer than stock.


The 81004, Airlift, Bilstein combination is catching on and given very good results for quite a few people now.

[Bjones7788]

I have an on board compressor, tank, rear bumper mounted air supply quick connect and set of "train" horns, towing various fairly heavy for the Roadtrek tow rating toy hauler trailers coast to coast. Any suggestions on tapping existing compressed air supply to handle the Airlifts. I assume the existing compressor puts out about 100-120 psi and I would tap the air line to install a variable pressure regulator to control the Airlifts. Any othe thoughts would be welcome. BJ

[booster]

All you really need to do is tap in to the air supply after the tank and run the line to one of the Airlift controllers or fill/relieve valves, and then to the airbags. We have a twin paddle switch manual controller in the driver side storage right at the rear and it works well.

[CaDreamin]

Sorry I don’t have the part number available. The bracket furnished required access from above which is not possible with a box frame.

[CaDreamin]

I would contact AirLift. What I installed was a complete kit with the manifold and compressor together. I don’t know if that manifold could be used with a different compressor.

The manifold does provide power to the compressor. It powers it up when it needs air and then switches it off when it does not. I am not sure how you would get power to the compressor when you needed it for other uses. There may not be a adjustable pressure regulator in the manifold, it would be much cheaper to simply turn the compressor on when you needed more air and then switch it off when you got to your target pressure.

[CaDreamin]

I just returned from a long trip.

LA
Williams, AZ
Grand Canyon South Rim
Marble Canyon (Page AZ area)
North Rim area
Las Vegas
LA

I spent lot of time on Forest Service dirt roads. These were in good shape for dirt roads, but they did have their rough spots. I got no scraping at all. Not even once.

Crosswinds were substantial on the Las Vegas to LA segment. Wind stability is substantially improved. Before the steering was quite squirrelly and very hard to control in wind. No more. A solid crosswind still pushes the van and you need to correct but the van feels very controllable the whole time.

Sharp bumps such was washboard roads or railroad tracks are still quite harsh. I was jealous of some pickups I saw flying along. But other than that all major areas are substantially improved.

Very satisfied with this upgrade, it did great.