Chevy Roadtrek Too Bouncy Backseat

[RTRanger]

We have a 2015 Roadtrek Ranger on the Chevy Express Van chassis (2500 with 4.8L) it has around 60,000 miles on it. I have driven Chevy work vans most of my life, so when we test drove this van it felt like a slightly overloaded van, but not too bad. After we bought it my wife and daughter sat in the rear seat (it’s back by the rear doors). I think it could have been compared to a bouncy castle! So I put new Bilsteins all the way around which helped considerably. I also added SumoSprings on the rear. But the ride in the back still isn’t great - or should I say acceptable. There is still some extra bounce but not the multiple bouncing like before, some of it might be caused by the rear seat softness. Up front the ride is very nice. While on a trip when my wife was driving on an interstate, I sat in the back and although I never have been carsick, I think I would have been if I stayed back there for a extended time. Could some of the unpleasantness be due to the geometry of being in the back of the vehicle and behind the rear axle? Would adjustable airbags on the rear fix this? I really would like to fix it so we could transport friends with having to supply “barf bags”.

[booster]

Originally Posted by RTRanger

We have a 2015 Roadtrek Ranger on the Chevy Express Van chassis (2500 with 4.8L) it has around 60,000 miles on it. I have driven Chevy work vans most of my life, so when we test drove this van it felt like a slightly overloaded van, but not too bad. After we bought it my wife and daughter sat in the rear seat (it’s back by the rear doors). I think it could have been compared to a bouncy castle! So I put new Bilsteins all the way around which helped considerably. I also added SumoSprings on the rear. But the ride in the back still isn’t great - or should I say acceptable. There is still some extra bounce but not the multiple bouncing like before, some of it might be caused by the rear seat softness. Up front the ride is very nice. While on a trip when my wife was driving on an interstate, I sat in the back and although I never have been carsick, I think I would have been if I stayed back there for a extended time. Could some of the unpleasantness be due to the geometry of being in the back of the vehicle and behind the rear axle? Would adjustable airbags on the rear fix this? I really would like to fix it so we could transport friends with having to supply “barf bags”.

I think it is hard to compare to the work vans as they may have been loaded differently, might not have been extended, and nobody was sitting in the rear.


That said rear ride in Chevies has been discussed and worked on several times here on the forum, so there are sources of very good information and successes, including our 07 190P Roadtrek. I think all have been on the 3500 chassis, though. Both 190s and 210s have been done.


I am not certain what the rear spring packs are on a stock 3500 with a 4.8L. It would be nice if you snap a pic and put it on this thread. In particular, we would be looking to see if it has the massive overload leaf at the bottom of the springpack. The overload has been shown to be the major cause of rear ride complaints in many cases as the the axle moves up quickly until it slams into the very stiff overload, giving a harsh stop of the travel.


The best results, IMO, have come from getting the van off of the overload leaf in normal driving by lifting the rear (and even better the front also to stay level) to be high enough not to hit the overload as often or as hard. Several of us have even removed the overload leaf.


To support the weight enough to get off, or remove, the overload leaf I think the Airlift rear 5000# bags do the best job. Some others prefer urethane helper springs, but I find them not to be my first choice.


The van is long, you are sitting behind the axle, and it is very heavy so it is going to move around on bumps and dips. The best solutions get results the somewhat increase the amount the van moves up and down, but turns the motion into a much smoother, less harsh, motion. A recent discussion of the posters work to get a 210 to be more comfortable in the rear explains it better as they have people riding back there and on a 210 you sit even further behind the axle.


You can try the search feature to try to find the discussion, and I will try to dig some up also, but a pic of the springs is the best place to start, I think.

[RTRanger]

I would say the ride is not harsh but bouncy. Hope this view is what you wanted:

[booster]

Yep, that is what we need.


If you look at the pic below, this is our 190 3500 Roadtrek with the overload cut off, but the center still used as a spacer. The spring shows 4 leaves without the overload.


You spring appears to have 3 leaves, which makes sense with a 2500 chassis. You are full on the overload, it appears, so it is going to be very high a spring rate in the back so it is going to be very stiff and a rough ride, most likely. You would not get the impact the 190s do as they sit slightly off the overload in many cases.


Do you happen to know how much each end of your van weighs. If not, it might be worth a trip to a scale to get the weight on the axle so we can see where it is compared to the 3500 vans the rest of us have. Our rear weight is in the 5000-5300# typically and a 210 Roadtrek can be closer to 6000# in many cases. You should be under that on a 2500, but you may still be close to a 190 as Roadtrek may have made it too heavy for a 2500. The 2500 has 1000# less gross weight allowance than a 3500. You should have a weight sticker somewhere around the front doors, probably driver side that gives max weight for each axle.

[TX-Trek]

Booster has very sound advice. I spent a lot of time researching suspension, suggest you also consider how the front to rear suspension interacts. We found that a lot of the bounce was related to front to back porpoising. Of course it won't ever be like a car but my end results are a huge improvement over the original setup.

Not saying you have to duplicate but this may add info....
https://www.classbforum.com/forums/f...des-13041.html

[RTRanger]

I have not weighed it since we bought it, it might be a while till I can weight it. We just sold our house and I’m a bit busy trying to remove all the stuff that has accumulated over the last 30 some years. Just can’t remember who carried all this stuff in here.

But here’s the sticker:

[booster]

That weight sticker is showing nearly 1500# less than a 3500 van would be at 3700# and change. With the van sitting heavily on the overload, it is very, very likely you will be over the limit on the rear axle for a 2500 van. The good news is that AFAIK, the big difference in the 3500 is just springs and shocks, so increasing the spring capacity and shock damping should be able to take care of it pretty well. You also need to make sure you get load range E tires on it so they can handle the real weight, I think. The front at 3800# is nearly 500# under max for a 3500 so you might also need a bit more spring in the front to prevent porpoising.



Let us know when you get the weights and we can proceed from there.

[TX-Trek]

Our door weight tag was about 4300F and 6000R. A visit to a CAT scale yielded the info below, fully "trip loaded" with water fuel food and us. Getting actual weight is of benefit especially if you are changing or modifying suspension.

[JohnnyFry]

Booster is correct on the rear springs. My 2008C210P could only be described as bouncy-bouncy with significant body lean on cornering. First stop, Bilsteins, which helped a lot but did not entirely put the issue to rest. The rear axle was resting on the bump stops. I took it to a spring shop...an establishment that specialized in big heavy trucks like concrete trucks and dump trucks. The foreman crawled under the van and took a look. He suggested removing the rear spring packs, adding a additional leaf and reassembling the pack. This cost in the neighborhood of $400 4 or 5 years ago and made a tremendous difference in ride and handling.

[booster]

I just took a look at the weight sticker again as it bugged me for a while when I thought about it.


It shows GAWR for the front at 3845# and the rear at 3725# which only totals up to 7570#. The GVWR is at 8600#. The weights on the label are close to what a 1500 van was when they still made them.



Axle weight ratings are always higher than the gross weight rating for the van, not lower, so I figured the rating sticker was wrong.


I looked up a 2500 non extended van and according to the brochure it would have front AGWR of 4100# and a rear GAWR of 5360# for a total of 9460#.


I don't know if the "new" Roadtrek would be able to get you a correct weight label or not, but it would probably be a good idea to at least check on it.


The original GM weight label should still be on the van also, and it would be correct, I assume.

[RTRanger]

I’m afraid this is going on the back burner for now. We were busy cleaning out the house we just sold, and thought we were seeing the light at the end of the tunnel - it was hurricane Ian.

Ian’s eye directly hit the island where our little winter bungalow sits. So far aerial photos and satellite images of the storm damage leads us to believe that it survived. The palm trees around our place are still there. One neighbor said the storm surge didn’t make it to our street. They are currently rebuilding the causeway and bringing in a temporary bridge. They predict homeowners will have access to the island in a week. So as soon as we get the word we’re heading down. A few more trailer loads out of our sold property then we’ll load the trailer with tools and supplies for Florida.

Our place is the near the red circle on the radar image below.

[peteco]

Originally Posted by RTRanger

I’m afraid this is going on the back burner for now. We were busy cleaning out the house we just sold, and thought we were seeing the light at the end of the tunnel - it was hurricane Ian.

Ian’s eye directly hit the island where our little winter bungalow sits. So far aerial photos and satellite images of the storm damage leads us to believe that it survived. The palm trees around our place are still there. One neighbor said the storm surge didn’t make it to our street. They are currently rebuilding the causeway and bringing in a temporary bridge. They predict homeowners will have access to the island in a week. So as soon as we get the word we’re heading down. A few more trailer loads out of our sold property then we’ll load the trailer with tools and supplies for Florida.

Our place is the near the red circle on the radar image below.

So sorry to hear of all the harm Ian did to Florida. Hope your place is OK. We winter in Lake Wales which had only minor problems thankfully. We visited Pine Island in Feb and liked that it has not succumbed to the urban sprawl like a lot of the coast. Let us know how you are doing when you get there.

[RTRanger]

We had a friend check on our Pine Island bungalow and it appears we have been extremely lucky. Our house is basically un-damaged. We lost some skirting and our electric service pole is down, but that’s nothing compared to the places beside us. We are planning to head south this week if all goes well. Got a bit of “survivor guilt” setting in already…