Chevy Suspension Upgrade Complete

[markopolo]

If the problem is still there with the new airbags then the airbag acting as bungee cords and snapping the van frame back toward the axle might be worth considering as a contributing cause.

I read about damaging airbags because of excess suspension travel when looking into putting them on the front of a Class A I had. Before that, I hadn't thought of them as being a suspension travel limiter.

I would be interesting to mount a camera under the van and record what is happening during the test drive.

[Bjones7788]

Interesting thinking about air bag, not jounce stop, contributing to rear end hop/bounce. Honing it down further to actual air bag, or jounce stop or a combination would be due diligence.

Since I have air bags off now, I could try to rig up a Hero video camera then do to record current situation then repeat with the new air bags with no internal jounce stop ( and of course my test equipment in the RT)

Thanks

BJ

[booster]

Originally Posted by Bjones7788

Interesting thinking about air bag, not jounce stop, contributing to rear end hop/bounce. Honing it down further to actual air bag, or jounce stop or a combination would be due diligence.

Since I have air bags off now, I could try to rig up a Hero video camera then do to record current situation then repeat with the new air bags with no internal jounce stop ( and of course my test equipment in the RT)

Thanks

BJ

My bet would be that it is the airbag causing the issue as IIRC even if you had it aired up to high pressure so well off the bump you had the same issue with no improvement. The airbag is going to be lower rate and not nearly as progressive as the massive overload leaf is.

[Bjones7788]

Thanks to Booster & Pete for the remarkable amount of the help in resolving this problem!

Our 2004 and 2013 Chevy Roadtrek 190s both had very low ground clearance with holding tank support straps, suspension bolts and crossover plumbing maybe 6 inches BELOW the vehicle frame rails. These Roadtreks are notorious for damage to low hanging plumbing components.

Even the front bumpers would grind against typical 8 inch high curbs in parking lots. So parking a long vehicle meant staying back from curbs with tail extended out uncomfortably far in many cases.

The most recent Moog front coil springs gave me 4 inches of front end lift - They are pretty stiff but in my opinion are still a good trade-off for the MUCH improved ground clearance from the front bumper to about half way back between front and rear vehicle wheels.

AirLift 5,000 rear air bags resulted in an increased hop or bounce in the rear of the vehicle. My wife said she would be thrown up off of the rear sofa/bed after the air bags were installed creating what she called a dangerous situation so she would no longer ride back there. This was regardless of the amount of air pressure - 10 PSI, 50 PSI or 95 PSI in the air bags.

I often tow a 7,000 pound toy hauler trailer with delicate cargo and with the air bags in place, and regardless of air pressure, tools hanging on the front walls of the trailer hopped off their hooks within a hundred miles or so of normal driving. This was not acceptable for my delicate trailer cargo and had not happened during our many annual annual trips from Maryland to California and back before the air bags.

AirLift was extremely cooperative offering to send a set of air bags without internal bump (jounce) stops at no cost. As things happen the shipment came very quickly but with only one new air bag without the suspect internal jounce stop.

In the mean time solid 3 inch rear lift blocks and 12 inch U bolts arrived so I installed the 3 inch lift blocks between the rear axle and the rear original equipment leaf springs. This gave me 3 inches more ground clearance at the rear fenders and a leveled the Roadtrek. Chevy Express 3,500 vans tend to exhibit a little nose down attitude from the factory so the final result looks more level than factory original.

Ride returned to normal meaning no more exaggerated rear end hop that came with the air bags. The tools stay on their hooks and my wife can ride in back, lounge, and conduct business.
(Without her Kindle, my wife is an extraordinary back seat driver when up front - most fortunately that situation is now also resolved - whew!)

If there is more to report as time progresses, I will followup.

Again, Thanks Booster and Pete !

BJ
Florida Keys

[booster]

Originally Posted by Bjones7788

Thanks to Booster & Pete for the remarkable amount of the help in resolving this problem!

Our 2004 and 2013 Chevy Roadtrek 190s both had very low ground clearance with holding tank support straps, suspension bolts and crossover plumbing maybe 6 inches BELOW the vehicle frame rails. These Roadtreks are notorious for damage to low hanging plumbing components.

Even the front bumpers would grind against typical 8 inch high curbs in parking lots. So parking a long vehicle meant staying back from curbs with tail extended out uncomfortably far in many cases.

The most recent Moog front coil springs gave me 4 inches of front end lift - They are pretty stiff but in my opinion are still a good trade-off for the MUCH improved ground clearance from the front bumper to about half way back between front and rear vehicle wheels.

AirLift 5,000 rear air bags resulted in an increased hop or bounce in the rear of the vehicle. My wife said she would be thrown up off of the rear sofa/bed after the air bags were installed creating what she called a dangerous situation so she would no longer ride back there. This was regardless of the amount of air pressure - 10 PSI, 50 PSI or 95 PSI in the air bags.

I often tow a 7,000 pound toy hauler trailer with delicate cargo and with the air bags in place, and regardless of air pressure, tools hanging on the front walls of the trailer hopped off their hooks within a hundred miles or so of normal driving. This was not acceptable for my delicate trailer cargo and had not happened during our many annual annual trips from Maryland to California and back before the air bags.

AirLift was extremely cooperative offering to send a set of air bags without internal bump (jounce) stops at no cost. As things happen the shipment came very quickly but with only one new air bag without the suspect internal jounce stop.

In the mean time solid 3 inch rear lift blocks and 12 inch U bolts arrived so I installed the 3 inch lift blocks between the rear axle and the rear original equipment leaf springs. This gave me 3 inches more ground clearance at the rear fenders and a leveled the Roadtrek. Chevy Express 3,500 vans tend to exhibit a little nose down attitude from the factory so the final result looks more level than factory original.

Ride returned to normal meaning no more exaggerated rear end hop that came with the air bags. The tools stay on their hooks and my wife can ride in back, lounge, and conduct business.
(Without her Kindle, my wife is an extraordinary back seat driver when up front - most fortunately that situation is now also resolved - whew!)

If there is more to report as time progresses, I will followup.

Again, Thanks Booster and Pete !

BJ
Florida Keys

Wow, Bob, excellent news on the bounce and certainly shows that there is never a "one size fits all" solution to things like lifts.



One thing that I would be a bit concerned about that you may want to take a look at would be how much front suspension down travel you have with the extra height. You may be right at the end of the shock travel depending on what shocks you have, and if the shocks don't stop the down travel could be getting perilously close to hitting the frame with the lower control arm. We had that exact situation when we wound up that high with the Bill Erb spring test. The fix, though not ideal, would probably to make sure you get a shock length that allows as much down as possible but stops the arm before it hits the frame. Probably a better fix would be to add a downtravel limiting strap. The lifted pickup truck folks get into this issue a lot and have bent a lot of control arms, so a high perf truck shop would probably know what to do.