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Chevrolet Express
Platform: GMT Van

Quest to enhance suspension (yet again)

Old Jan 30, 2019 | 12:31 PM
  #21  
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983_vanbuilder (or anyone else)

Do you have experience with heavy duty shocks like the KYB Monomax on the Express/Savana? I recently bought a set of 4 KYB Gas-a-Just for my 2016 ext passenger 3500, after I found one of the front factory shocks leaking and experienced less than admirable porpoising when towing (https://www.carid.com/kyb/gas-a-just...pn-554356.html and https://www.carid.com/kyb/gas-a-just...pn-554348.html). When they arrived I checked them to make sure they were damage-free from delivery before I set them aside to wait for a good weather day to do the work. While I was inspecting them, I was surprised that I could compress the shock using just a little body weight (I'm not a wimp, and weigh about 250lbs). I am considering the Monomax for the rear (https://www.walmart.com/ip/KYB-56503...Shock/47466924) since I use our van to tow a 7500# travel trailer, but I don't want ride quality to suffer when I'm not towing. I also have a set of Sulastic shackles (Sulastic. Leaf Spring Shackle) that I plan to install when I replace the rear shocks. I want to improve the ride quality for passengers when not towing, and when we take our travel trailer on the road.

Does anyone have towing experience with the Gas-a-Just or the Monomax? empty with either set of shocks? Ride quality seems to be a difficult thing to dial-in on these beasts.

This seemed like a good thread to ask the question....
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Old Jan 30, 2019 | 2:06 PM
  #22  
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Originally Posted by GatorHawk24
I was surprised that I could compress the shock using just a little body weight (I'm not a wimp, and weigh about 250lbs).
Not surprising at all. Resisting compression is not the job of shock absorbers. That's what springs do. Shocks should just slow it down.
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Old Jan 30, 2019 | 2:19 PM
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Originally Posted by mountainmanjoe
Not surprising at all. Resisting compression is not the job of shock absorbers. That's what springs do. Shocks should just slow it down.
Yeah, I know they are there to dampen spring action... I haven't replaced a set shocks in a really long time (so no recent mental reference), and the last set I replaced were for a small car. I guess I assumed that for such a large vehicle it should've taken more pressure to compress it. I've heard good things about the Gas-a-Just, and the compression rate was nice and slow. It will be interesting to see how the old ones respond to the same test after I replace them.

Last edited by GatorHawk24; Jan 30, 2019 at 2:22 PM.
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Old Jan 30, 2019 | 8:35 PM
  #24  
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So far so good with the GAS-a.just. No reference either, cause this is my first time with this size of vehicle. I was going for the bilsteins but they were always in back order and was sick of lack of shocks.
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Old Feb 20, 2019 | 11:12 AM
  #25  
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So, I finally installed new KYB gas-a-just shocks on my 2016 extended 3500, and there is a significant improvement in ride quality. I had no idea that my 2 year old shocks could be in as bad of shape as they were. I could compress them between my hands and they made no attempt to recover... just squish, and done.

I do not have the "boat" feeling like GeneveConversionVan mentioned, but I'm on a 3500 suspension not the 1500 (so I assume that's why). The new shocks have basically erased the lurch and most of the jounce that I experienced with my old shocks, but I still want to smooth out the initial shock of expansion joints, large cracks, and road imperfections (if possible, and I don't plan to deflate my tires to achieve this). I agree with 983_vanbuilder that I'm not getting much out of my leaf springs since the platform spring is basically engaged 24/7. I tried to install a set of Sulastic shackles, but I couldn't test them since they made contact with the rear post where the body attaches to the frame (I've tried to contact Sulastic to see if I have the wrong version... I really hoped they would be the answer I was looking for).

GeneveConversionVan, did you end up installing the Roadmaster Active Suspension? Do you (or anyone else) feel that they achieve at least some of the these desired results? I'm also interested in them since I use my van to tow a camper and their claimed suspension improvements are intriguing.
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Old Feb 20, 2019 | 11:24 AM
  #26  
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No I havent!
Have been in endless meetings and business trips so i left the Van project aside for some weeks.
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Old Mar 2, 2019 | 10:15 AM
  #27  
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You can also try Sumo Springs. I've always looked at them as snake oil, but the people who use them swear by them.
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Old Mar 4, 2019 | 9:14 AM
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Originally Posted by CptDondo
You can also try Sumo Springs. I've always looked at them as snake oil, but the people who use them swear by them.
Oh ok thanks, I will take a look on them.
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Old Jan 3, 2020 | 3:52 PM
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Hey everyone. In the endless quest to improve ride quality for general driving and when towing, I decided to try out the Roadmaster Active Suspension. I found them on sale for a great price around Christmas, and I installed them yesterday. I've only driven my van about 30 miles since the install (no towing yet), but so far I'm impressed. For reference, I have a 2016 passenger 3500 with a ride-share up-conversion (bucket seats bolted to a steel sub-floor, instead of benches in rails) that we load up with 2 adults and 6 kids. There's always a load in that thing. Prior to install, the heavy-duty platform spring was essentially engaged 24/7, after the RAS I now have a little space in the spring pack and they are able to take bumps MUCH better. When I get more time, I'll include pictures of the install, and I'll update the thread again after we tow our camper (no immediate plans to do so, though).
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Old Mar 2, 2020 | 11:30 PM
  #30  
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get away from the computer and buy a tape measure.. mine had 3 leaf springs when I got it. Found late 70s 1 ton 4x4 w 56 1/4 springs $35. 2003 suburban I believe has the big gas sachs shocks. You will need a ratchet strap to install and ends will need trimmed down. $24 more and van is smooth and solid.
I'm tinkering with a front sway bar from dodge van for my rear. If I get it to work and machine my own delrin bushings it may be $50 more
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