Suspension upgrades! Success

[jojobafanzi]

I'm starting this new thread about my suspension upgrades and as a final update on a previous thread I started called "Trac Bar?" about my 2017 RT 170 Versatile. The short story being that the van handles much better now. Success! From the day I acquired the 170 V, the handling was miserable and front end alignment would go out very quickly.
First I replaced the shocks with Bilsteins. I replaced the tires with Michelin Agilis Cross Climate tires. I have always liked Michelin tires but I'm still deciding if I like this new model of Michelins.
The reason the front end alignment would go out was a defective upper control arm bolt. The bad threads prevented the proper tightening so alignment went out fast. I also changed the bolts and cams out for locking cams so issue never happens again.
That bought me to the rear. I installed a rear sway bar and a rear trac bar. After installing the rear sway bar, the vehicle handling and cornering improved greatly. The final modification was the addition of the rear trac bar and improved the ride even more. So far, the modifications were worth the time and mney spent. Cheers! Joe

[andrewtschneider]

I upgraded the rear shocks and swaybar on my Sprinter 3500 2014 Pleasureway Plateau.
The handling is much much better.
Agile Off Road caters to the off road crowd.
I have less body roll and sway.
Plan to upgrade the front end next.

https://agileoffroad.com

[Anachr0n]

For my 1998 Dodge 190 Popular I’ve been debating either adding 2” rear spacers so front and back are aligned , or the aforementioned sway bar, or both. I’ve already done the front steering linkages.

I’m trying to improve the cornering. It feels like the back end is ‘tippier’ than the front. I’m not sure if it’s because the rear wheels are closer together (like standing with your feet close together), or because the sway bar is letting the chassis lean over too much (like letting your knees buckle).

Which will get me the most bang for the buck?
Has anyone done both at separate intervals?
And if so, which helped the most?

[rowiebowie]

This thread is getting complicated fast as we have a Chevy Express, Mercedes Sprinter, and a Dodge all with totally different suspensions but all with the common "How can I improve ride height & handling" questions.

[booster]

Originally Posted by rowiebowie

This thread is getting complicated fast as we have a Chevy Express, Mercedes Sprinter, and a Dodge all with totally different suspensions but all with the common "How can I improve ride height & handling" questions.

I agree. Best if the new questions that aren't on the same brand as the OP has should really start a new thread for their own ease and responses and to make it easier to find in the future for the next person with a similar question and brand.

[beauregaard]

I'm pretty sure this alignment bolts on the MBs are stretch, single use bolts and should be replaced every time they are loosened.

[romeo]

I have recently downgraded from a diesel pusher to the Roadtrek van. We have to load the van pretty heavily for our seasonal migration and we do tow a Jeep Grand Cherokee.

I find that the van feels "light" on the front end when steering and especially during cornering which I call "over steering". I have adjusted the tire pressure lower in the front tires in an attempt to minimize the oversteer. it seems to help a bit, but do not want to run the tires very far below the recommended pressures.

I'm sure that someone knows what can be done with sway bars and additions to the suspension to make it safer and more comfortable to drive; however, I don't have any leads on local shops that that I know have the experience to help without spending a lot on experimenting with my money. I am interested in hearing from those that may have had similar problems and how they resolved them.

Ron

[booster]

Originally Posted by romeo

I have recently downgraded from a diesel pusher to the Roadtrek van. We have to load the van pretty heavily for our seasonal migration and we do tow a Jeep Grand Cherokee.

I find that the van feels "light" on the front end when steering and especially during cornering which I call "over steering". I have adjusted the tire pressure lower in the front tires in an attempt to minimize the oversteer. it seems to help a bit, but do not want to run the tires very far below the recommended pressures.

I'm sure that someone knows what can be done with sway bars and additions to the suspension to make it safer and more comfortable to drive; however, I don't have any leads on local shops that that I know have the experience to help without spending a lot on experimenting with my money. I am interested in hearing from those that may have had similar problems and how they resolved them.

Ron

Does it change with or without the Jeep behind it? Pulled 4 down?


Generally when I hear "light" to describe the steering feel it would mean the van is not responding to steering inputs until they are quite large. When you turn a corner you have turn the wheel to much to make it turn. If so that is understeer you are feeling. Oversteer is when the rear tends to want to walk out on turns, like happens with rear drive on ice.


If it is understeer, you would want higher front pressure, not lower to help address it. Having the most positive caster will also help. Good shocks that are firm enough help. A big swaybar in the rear will help a lot. All this is assuming that front steering parts are tight and steering box properly adjusted and not worn out.


There are many discussions here on handling of our vans, including the Dodge, Chevy, Sprinter and Promaster vans Roadtrek used. Some vans just handle better than others across the brands and need different fixes.


Be aware that nearly all the Roadtrek tire pressure labels are just copies of the manufacturers pressures given for empty vans but still having barely the load carry capacity of rated. Most of the RV conversions are being run at higher than those labels, particularly in the front. Chevy labels say 50/80 and most of us run 65/80 for instance.

[rowiebowie]

Originally Posted by Anachr0n

For my 1998 Dodge 190 Popular I’ve been debating either adding 2” rear spacers so front and back are aligned , or the aforementioned sway bar, or both. I’ve already done the front steering linkages.

I’m trying to improve the cornering. It feels like the back end is ‘tippier’ than the front. I’m not sure if it’s because the rear wheels are closer together (like standing with your feet close together), or because the sway bar is letting the chassis lean over too much (like letting your knees buckle).

Which will get me the most bang for the buck?
Has anyone done both at separate intervals?
And if so, which helped the most?

Older recirculating ball steering Dodges in the 1970's had the ability to adjust some slack out of the center feel. Don't know if this adjustment was still there in 1998, but it was as simple as backing off a ring nut and turning the center bolt on the steering box clockwise about 1/2 to 1 turn and re-tighten the ring nut to hold the adjustment. You didn't have to worry if you tightened too much, it would become evident on a test drive when the steering wheel would resist returning to center. Just repeat the process and back off slightly or tighten more until you got it right.

[romeo]

Originally Posted by booster

Does it change with or without the Jeep behind it? Pulled 4 down?

Generally when I hear "light" to describe the steering feel it would mean the van is not responding to steering inputs until they are quite large. When you turn a corner you have turn the wheel to much to make it turn. If so that is understeer you are feeling. Oversteer is when the rear tends to want to walk out on turns, like happens with rear drive on ice.


If it is understeer, you would want higher front pressure, not lower to help address it. Having the most positive caster will also help. Good shocks that are firm enough help. A big swaybar in the rear will help a lot. All this is assuming that front steering parts are tight and steering box properly adjusted and not worn out.


There are many discussions here on handling of our vans, including the Dodge, Chevy, Sprinter and Promaster vans Roadtrek used. Some vans just handle better than others across the brands and need different fixes.


Be aware that nearly all the Roadtrek tire pressure labels are just copies of the manufacturers pressures given for empty vans but still having barely the load carry capacity of rated. Most of the RV conversions are being run at higher than those labels, particularly in the front. Chevy labels say 50/80 and most of us run 65/80 for instance.

I guess I should mention that my 2015 Roadtrek is built on a Chevy 3500 chassis with the 6.0L, Vortec engine.

True "oversteer" and "light" appear to be contradictive terms.

1. You are correct in you definition. I did mean oversteer when turning into a curve, vehicle responds too much and one needs to correct by steering less, or back right on left-hand turn. My mistake to mention "light" along with "oversteer". So it must be that I haven two different situations to deal with.

2. Aside from oversteering the "light" feel to me is the loss of road feel: it feels like one needs a large chunk of concrete on the front to keep front tire pressure on the road surface.

2. Oversteer does happen when towing, but that is the time when we are loaded with the maximum load when travelling South for the Winter. The load is primarily in the rear end of the van.

3. I do know that there is a front sway bar, probably factory installed, but don't know if it is standard to install a rear sway bar to keep the front wheels down, I will check, I can get under the enough to find out.

You did mention something I had considered and that was wheel alignment.

The van appeared to be well maintained by the previous owner and I have not detected anything that I would link to the need for front end repair. The previous owner did add heavy duty brakes so he was aware of additions to provide better travelling conditions.

A rear sway bay is something I have considered, but sure if it would resolve my problem and not aware of a shop in Spokane that would have the expertise to make recommendations.

The van came with 50# front and 80# back. To help resolve my problem I dropped the front a couple of pounds to maybe 48 or 49#. It helped a bit but not enough to say it resolved the problem. As I mentioned, I didn't want to drop the pressure to much and start get bad tire wear.

[booster]

Originally Posted by romeo

I guess I should mention that my 2015 Roadtrek is built on a Chevy 3500 chassis with the 6.0L, Vortec engine.

True "oversteer" and "light" appear to be contradictive terms.

1. You are correct in you definition. I did mean oversteer when turning into a curve, vehicle responds too much and one needs to correct by steering less, or back right on left-hand turn. My mistake to mention "light" along with "oversteer". So it must be that I haven two different situations to deal with.

2. Aside from oversteering the "light" feel to me is the loss of road feel: it feels like one needs a large chunk of concrete on the front to keep front tire pressure on the road surface.

2. Oversteer does happen when towing, but that is the time when we are loaded with the maximum load when travelling South for the Winter. The load is primarily in the rear end of the van.

3. I do know that there is a front sway bar, probably factory installed, but don't know if it is standard to install a rear sway bar to keep the front wheels down, I will check, I can get under the enough to find out.

You did mention something I had considered and that was wheel alignment.

The van appeared to be well maintained by the previous owner and I have not detected anything that I would link to the need for front end repair. The previous owner did add heavy duty brakes so he was aware of additions to provide better travelling conditions.

A rear sway bay is something I have considered, but sure if it would resolve my problem and not aware of a shop in Spokane that would have the expertise to make recommendations.

The van came with 50# front and 80# back. To help resolve my problem I dropped the front a couple of pounds to maybe 48 or 49#. It helped a bit but not enough to say it resolved the problem. As I mentioned, I didn't want to drop the pressure to much and start get bad tire wear.

50 and 80 psi are sticker pressures for the Chevies and generally considered to low in the front so take the front up to 65 psi and see what it does.



The clarifies a bunch. Very, very unusual to have one that needs less steer once in the corner, but there is one scenario that might cause that, and that is that the van is toed out instead of in. Toe out can make a vehicle turn in very quickly at the beginning of a turn and even try to self turn more sometimes. Toe out also makes it hard to hold a straight line at speed and will try to dart from side to side with corrections. You can check the toe in you driveway with a tape measure and two people. It is very near impossible to have vehicle with 5000#+ on the rear axle have the rear end step out on drive pavement and normal speeds. I think the van would tip over before that happened. On ice, yes, wet maybe, but once it started you probably wouldn't be able to catch and would go around.



Is the tail wagging from load also with the jeep on? If so does it also do it when loaded but no jeep.


It would be good to know if it is a 170, 190 or 210 as they all will have different weight distributions with the 210 being the worst for light front end because of the long rear overhang and high rear weight. It is also very easy to overload a 210, less easy to overload a 190 but can be done, and 170 are kind of the lightweights on the shorter 2500 chassis.


You may want to start by getting to the scales when fully loaded to get your axle weights to see where you stand. Also get a tongue weight of the setup loaded and with the jeep on it. Overloading the rear axle is very common on the Chevy class bs when towing as there isn't a lot of headspace before you max out.


A 2015 should have the same steering gear as our 2007 190 and it should actually feel a bit springy return to center, even at low speeds as it appears to be built into the gear that way. I would not call it easy as it is effort even in the center at highway speed.


Also a question which wheels it has on it. Aluminum or factory steel wheels. The aluminum wheels have the wrong offset and can affect the handling and steering feel.


Look for a shop the specializes in trucks like tradesman vans, delivery vans, and other light commercial trucks as they will accustomed with the old school setup of the Chevies.