Lift '95 RoadTrek body (Dodge chassis)?

[Crank]

I want to assess the potential for raising the body 2-4" of my 1995 RoadTrek P190 (on Dodge B3500 chassis). I am concerned, like many others, with the poor underbelly clearance ( the van bears evidence of the problem I like to camp off-road, and while the RoadTrek will always be limited, I’ll pass on paved campgrounds when possible.

I’m sure this is the place to get some advice on how to approach the problem, and to some helpful sources, having read many threads on other vehicles.

Unloaded, the van drives very nicely: I have not tested it loaded yet, but from reading many threads here, I know that handling can be an issue when one starts altering the suspension.

I have learned that raising a vehicle is much more complicated that I expected, and I feel overwhelmed by all the unfamiliar terminology and mechanics: I doubt there is much off-the-shelf material for this older van, and I will need to find a mechanic who can either engineer a solution, or install the parts that are needed. When I find a mechanic, I need to know enough to evaluate his capabilities, unless one is referred to me. It may be worth driving far out of state, if someone can identify an expert who knows how to address the problem.

I also realize that the project can be quite expensive, and I will have to weigh the cost of solutions against the value of my old van (about $12K). Any thoughts on that?

So the floor is open. I will greatly appreciate any comments and suggestions on how to approach the problem, or references to relevant sources for my particular vehicle or something sufficiently similar. I hope to gather enough solid information to proceed later in the year. Thank you.

[wincrasher]

I don't know much in the way of specifics as far as recommending what you should do. Other than go to a local truck shop and talk to whoever runs the place. If you line out your wishes and set a budget, I'm sure they can recommend some things.

I've seen a few videos on youtube about such projects. One that I recall I really liked was a van with an adjustable height air suspension. That may kill a few of your birds with one stone. You could add a few inches going off-road (more likely on-trail) but return to a normal drive height on the highway and maintain your high speed driving characteristics.

I suggest you get a realistic idea of what kind of off-roading you want to do. Forest service roads? Or you want to climb rocks with the van? I suspect you are really only wanting a bit of extra height and maybe some better/wider tires. That should be fairly easy. If you want a lot of articulation, and huge tires, that gets more complicated, and of course, more expensive.

[booster]

It appears that Firestone and Airlift both make air bag setups for the rear, so that part is pretty easy and under about $500. On the front, Tuftruck and some others make heavy duty springs, but list them for stock height. If your Dodge is like our Chevy, the extra loading from the conversion pushed it down 2". By using stiffer, stock height, springs, we got back to factory ride height which was 2" higher than from Roadtrek.

[Crank]

Thanks for your suggestions, gentlemen.

I don’t plan on extreme off-roading – this is not a 4x4! I plan to travel forest and BLM roads sometimes, especially in search of a camp site, and so I want the ability to navigate rutted areas, sharp dips and rises, and cross the roadside grader spoil to get to a good camping spot a few yards off the road. I don’t plan to tackle anywhere near the worst roads and certainly not muddy ones, so I don’t plan on changing to more aggressive tires at the moment.

I like the idea of temporarily raising the clearance with air bags, and so preserving the highway driving characteristics. I’m glad to know this is possible in the rear, Booster, but I did not follow your discussion of the front. Do you mean that raising the rear depresses the front, and that HD coil springs only compensate for that? Or do you mean that coil springs AND air bags would be needed? Are you also saying that your factory clearance is 2” higher than RT?

I wonder if the steering gear is an impediment to using air bags to raise the front.

I don’t know the differences between Chevy and Dodge chassis back around ’95. Most of the discussions I have seen are about Chevy, and leave me wondering what to conclude.

Maybe someone else will jump in with some other ideas.

[booster]

The intent, if it would work, would be to use the air bags in the rear, and new, stiffer springs in the front. The problem is the only front springs I found were stock length, but they may raise the front end quite a bit if it is sagged from all the extra weight of the Roadtrek conversion. That is how it works on the Chevies, as they are down 2" from stock height after Roadtrek gets done, so if you put in the same length spring, but stiffer, they come back up that 2" to where they were before the converting. Same in the rear with the air bags. You should be able to find what the factory ride height spec is in a service manual, or you could get it from an alignment shop. The spec will tell you exactly where to measure and what that measurement should be, both front and rear. The good thing is that if you get back to factory height, your handling will probably get better, not worse. That is what happens with the Chevies.

Adding the bags in the rear without doing anything in front will make the front go down a tiny amount, and will also change your alignment angles a little bit, but not major in either case.

[Crank]

Ah, thanks for the clarification Booster. I have seen reference to the sag in Chevys, not on the Dodge, so far. I'll certainly check with my local alignment shop. But I think I'll need a specialist shop eventually: I might find one in El Paso, TX, or in NM. Recommendation, anyone?

[Photog]

On our Chevy vans, the front shock absorber is mounted up through the center of the coil spring.
If your dodge van has the front shock mounted outside the spring, there is an airbag that can be used inside the coil spring.
I don't know how well these work, inside a coil spring, but it may give you an ability to adjust the front ride height and spring rate.

[Crank]

Thanks for the suggestion. Photog.

The van is in the shop now, awaiting installation of a pair of stout-looking coil springs 1" longer than stock.

So I can't go outside and check the shock arrangement.

Air bags fore and aft might be an interesting possibility, especially as a supplement to steel.

[Photog]

If you are upgrading the front coil springs, it is not likely that you will need airbags in the front.

[Crank]

Well, I'm happy to report that my alignment man also is experienced in suspension mods. Replacement of the front coil springw with springs a little longer, and adding a leaf and a shim to the rear brought my '95 Roadtrek up at least to factory specs, removing the original weight sag and 20 yr of added tiredness Cost was about $1000, which I think is reasonable considering my man was very exacting, and there are certainly more expensive ways of solving the problem.

I now have about 12 inches of underbelly clearance (excluding differentials, of course) and I am happy with that. I probably will not need new shocks, but have not driven enough to be certain. The van drives just fine.

By the way, the shocks do not go through the coil springs.

Thanks to those who made suggestions. I hope this is a helpful recipe for others with the same problem.

[AZ ADVenturist]

Hey Crank, where in NM are you located? L.Cruces area I assume? And where is your suspension guy? I'm in Prescott (area) AZ. Still looking for a qualified "lift" specialist for R/T. Thnx Ric. In Arizona

[Crank]

The shop I used is called J&M's Frame & Alignment in Alamogordo, 88310 NM.
575-437-3202. Jerry, the owner is a fine, honest and exacting man who has done jobs for me for 30 years, and wants to save me money. Can't recommend him more strongly.

I would not say he is "a qualified lift specialist for RT"; I don't know if there is such a thing. But he knows his stuff. If you want more lift than I had. it gets a lot trickier.

If you want to have him do the same job, you would need to leave the van for a few weeks (order in parts, you know: I had a long wait for the leaf springs). Or, if you are sure you want the exact mod I had, on the same model, you might be able to have him order in the parts, then drive here for installation and only have to wait for a night or two.

Give Jerry a call and tell him you were referred by someone who just had the job I described done by him on a 1995 Dodge B3500 chassis. Please pm me if it looks like you will have the job done here and I'll see if I can help you out any.

A 1st class mechanic is worth a deal of travel!

Good luck!

[olddodgevan]

What shock absorbers are you using? Maybe others can chime in about their experience with different brands/models.
I have replaced front coils and added air bags to the rear. Also added 1 1/2 spacers to the rear wheels.
Big improvement but I still need to replace the existing shocks.

[Crank]

Olddodge, I don't know what shocks I have, and the van is gone for a couple of weeks for a paint job.

I can tell you that my man thought the old shocks were OK: standard shocks don't affect lift, but a lift may require longer shocks. I thought the ride was a little harsher than before (tire pressure was about 80 psi all round). At 55psi in the front and 80 in the rear, which is what the guide calls for, the front end is too bouncy, and there is a little lack of firmness on curves. Then I realized the guide gives pressures for the pickup and van, not for the heavier conversion,
so I will have to increase the pressure all round by about 10# I expect. Probably this will correct matters and I won't have to change shocks. But I expect I will always have a harsh ride on rough surfaces - the price for a stiffer suspension. [Edited 4/02].

How much lift did you get, and what is the underbody clearance now? I got about 3" lift, and about 12" to the tanks. I was told that any more lift creates problems with the front end geometry, and would require a more complicated and expensive solution.

[olddodgevan]

I got about 2.5 inches of lift in the front with the new coils which are much beefier than the originals. Still playing with the rear air bags, but have them set about 3'' taller than before install(for towing). I haven't measured ground clearance yet.

[Crank]

That's a pretty good improvement in clearance. Is the van leveled out, or do you need to raise the front a little?

How much total lift can you get out of the air bags - I would have thought it would be limited by resistance from the springs?

Please note I made an edit on tire pressure to my previous post.

[Crank]

This might be a good time to bring up the problem of defining lift in relation to stock clearance.

Booster and Photog, this might be one for your experience!

The entire subject is muddied because of the many different suspensions used by vans, but particularly by the differences between Chevy and Dodge chassis and different Roadtrek models.

I would like to know what the stock suspension clearance is on my 95 Dodge Roadtrek Pop B3500. How is “IS stock” defined? How and under what conditions it is measured: loaded or unloaded? And more critically, how much underbody clearance does that gives to the vulnerable tanks and plumbing. Lots of us are boondockers who need to know such things. The data is probably out there in bits and pieces, if only one knew where to look. It would be nice to see it compiled in one place.

These questions are more complicated than they seem. There may be different chassis load adjustments and clearance specifications for the 3 Dodge chassis 1500, 2500 and 3500, and for the Chevy series which has a different suspension design. So any discussion needs to start with the vehicle fully specified!

But then Roadtrek loads down the suspension with all kinds of stuff probably weighing over 1000lb. and puts several different models on the road. From the point of view of the new van owner, the stock clearance is what Roadtrek delivers to him, and I have not seen those figures published. Add to that the load the driver must add for a trip: fuels and water weigh 508 pounds alone: probably another 1000 lb in total.

I don’t know if Roadtrek modified the suspension to adjust for the extra weight they added: if they did, they did not make it beefy enough, judging from the number of sagging vans around.

My working assumption is that Roadtreks of that era lost an inch of clearance during the conversion and sagged another two inches over the next 10-15 years, road clearance becoming perilously low for the long wheelbase (going by the number of discussions on how to raise the vans back to “stock”, whatever that is).

So I am pretty happy to have gained 3” of clearance, but I am not fooling myself I have a high-clearance van: I have a normal van. I would have liked true high-clearance (more than stock), but that would take some more complicated and expensive engineering.

What is the maximum wheel and tire size the wheel well will accommodate? Going up a size might provide a relatively cheap ¾” additional lift when new tires are due, perhaps without creating alignment problems, especially for those who have the 3.9 liter engine. The gearing up caused by increasing tire diameter can be a problem with smaller engines, especially if towing.

When I read old threads about someone seeking to, or having raised their van, my question is always “from what”: that is, what is or was the current ground clearance, and where was it measured. As a rule of thumb, “normal” seems to be with the bottom of the running boards about level with the center of the hubcaps

[markopolo]

Trim Height specs might be the starting point. That's what Chevy refers to it as. You should be able to find those specs in a good shop manual or from a dealership. You'll also need the instructions for how and where to take the measurement. The instructions are different for the front and rear. You might find two sets of specs - with or without auxiliary springs and there's a tolerance allowed. You measure three times (jouncing in between) to get an average measurement.

I read up up on it for my van when looking into replacing the shocks. Checking Trim Height was the starting point if suspension problems are suspected (my understanding).

I wish it was a simple measurement like bottom of frame to ground but it is not. For my van, the front is measured from the center line of the pivot bolt center line to the lower corner of the lower ball joint. For my van, the measurements were to be taken with a full fuel tank and spare tire on-board.

I don't think I ended up taking the measurements because I doubted I could do it accurately. I was going to replace the shocks anyway.

[booster]

Marko gives very good advice in regards to the trim height (GM term). I have also seen it called "ride height" and "suspension height" other places. Chevy Roadtreks are sent out of the factory at about 2" under factory trim height recommendations for the van, because of all the added weight.

I like the term "suspension height" because it says what it is really measuring, the actual height that the suspension parts are set at. The somewhat tough measurement that Marko mentions in the GM spec is the way it is called out our 07 Chevy also, and it is basically measuring the position of the lower control arm compared to level wheels. The position of the lower control arm tells exactly where the entire front suspension for that wheel is sitting, so it can be compared to the place the designers want it to be for best performance. In the world of chasing odd handling problems, it can be very important.

The rear dimensions are usually done similarly to determine the height of the rear axle in relation to the front pivot on the leaf spring that the rear suspension rotates around when it moves. Again, it is compared to what the designers wanted. The rear tends to be less critical than the front, but can still be an issue on some vehicles, primarily the ones that have quite a bit of rear travel and short leaf spring segments in front of the axle. This setup gives an automatic "rear steering" because one wheel moves forward (inside wheel on a turn) and one wheel to move rearward or not just as much forward (outside wheel in a turn). Where the axle is in the rotation compared to pivot can affect the whole thing. High rear steer vehicles also will exhibit more "bump steer" from the rear on one wheel bumps.

The easiest way to measure the heights is to find yourself a spot of level concrete. If you can't scoot under far enough, drive it up on equal height blocks on all 4 wheels. Don't jack it up and set it on the blocks, as that will mess up the front height. Bounce it a couple of times. Take a small plumb bob and use it to find and mark the spot on the ground under the two points you need to measure to. Measure from the point on the ground to the measuring point on the van in both places and subtract one the lowest from the highest. Alternately, you can skip the plumb bob routine and measure the height from the ground to the point with small machinist square if you have room. The important thing is to be square to the ground to get an accurate reading,

I don't like to be much more than about 1 inch different from the spec in the front and maybe 2-3 inches in the rear, but others will say they have no issues with more than that. Where you are in the height might make it so you need longer or shorter shocks to prevent bottoming or topping them out. If you are getting close to the suspension bump stops, or hard stops, you could be in danger of damage on big bumps. If you are off of spec much in the front you may not be able to get to the factory alignment specs, or even require slightly odd settings to optimize handling and things like bump steer.