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.

[romeo]

Originally Posted by booster

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.

I'm afraid that 65psi would put me in the left-hand ditch as soon as I tried to make a left-hand turn..

"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"

That makes sense, and it doesn't really feel like that would happen, so that is confusing. So thinking out loud: what would cause oversteer without a tendency for the rear-end to come around... Hummmm. Guess I will lay awake tonight thinking about that...!

No tail wagging. No complaints on how it tows and I don't have any indication of too much tongue weight: thinking of my 21'boat tongue weight on my Tahoe. The RoadMaster tow bar doesn't place any tongue weight, to speak of, on the towing vehicle, just pulling weight.

In my original message, I did mention that the van is a 210, if that changes any of your ideas.

The van has factory Aluminum wheels.

Another thing that is confusing me is that my net searches bring many videos that discuss anti-sway bars. It seems that I am hearing that a front sway bar can cause oversteer ??? Now, I have never heard discussions on sway bars causing over or under steer. When I was into autocrossing sport cars we heard one used a front sway bar to keep the rear wheels from lifting off the ground. I have seen cars on the course lift one of the rear wheel off the ground in tight turns. These were cars not set up for autocrossing and that's why they had the problem. Those of us that set our cars up for that type of event, always installed a front anti-sway bar. For over/understeer I would adjust tire air pressure. I can't find any link that will specifically answer the question of keeping the weight on the opposite end of the installed sway bar.

[booster]

Originally Posted by romeo

I'm afraid that 65psi would put me in the left-hand ditch as soon as I tried to make a left-hand turn..

"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"

That makes sense, and it doesn't really feel like that would happen, so that is confusing. So thinking out loud: what would cause oversteer without a tendency for the rear-end to come around... Hummmm. Guess I will lay awake tonight thinking about that...!

No tail wagging. No complaints on how it tows and I don't have any indication of too much tongue weight: thinking of my 21'boat tongue weight on my Tahoe. The RoadMaster tow bar doesn't place any tongue weight, to speak of, on the towing vehicle, just pulling weight.

In my original message, I did mention that the van is a 210, if that changes any of your ideas.

The van has factory Aluminum wheels.

Another thing that is confusing me is that my net searches bring many videos that discuss anti-sway bars. It seems that I am hearing that a front sway bar can cause oversteer ??? Now, I have never heard discussions on sway bars causing over or under steer. When I was into autocrossing sport cars we heard one used a front sway bar to keep the rear wheels from lifting off the ground. I have seen cars on the course lift one of the rear wheel off the ground in tight turns. These were cars not set up for autocrossing and that's why they had the problem. Those of us that set our cars up for that type of event, always installed a front anti-sway bar. For over/understeer I would adjust tire air pressure. I can't find any link that will specifically answer the question of keeping the weight on the opposite end of the installed sway bar.

There is something really odd going on, for sure. Higher pressure should not but you into a severe over turning situation. I don't really think it is classic oversteer because that is lack of traction on the rear end.


The information that you saw about swaybars is correct even if it is counter intuitive. They work backwards from how you would assume. Increasing the size or adding a swaybar to one end improves the traction of the other end. In your autocross example that meant getting both tires on road with more weight on them in the rear and the front bar did that. That means that adding a rear bar would improve understeer by improving the front traction. But that isn't what you have.


The only thing that I can imagine that would do what you say is happening is if the front wheels are self steering and that can only happen if something is not right in the geometry.


If a vehicle is aligned with negative caster it will self steer as soon as it is off center with no input from the driver. The old manual steering, heavy, rear drive cars were aligned that way to give them "light effort" steering. They were also all over the road trying to keep them straight.


Another is if the toe is set out instead of in. As soon as the outboard tire passes the straight ahead position in it's transition to turned in the turn rate will increase noticeably. If there is any slack in the front end parts or steering gear that extra turn in can be quite large and unnerving. Road race cars use towed out as it gives good turn in response and holds corners better but I think the also use large positive caster with it. Toe out is bad on the street vehicles though as it makes them less directionally stable and makes turn in feel odd. Toed out cars are often called twitchy.


Very loose front end parts could also probably cause what you feel. Once you start to turn all the slack goes out. Sometimes there is a point where you actually can feel it in a car that is tight in the front parts, from what I saw on my 96 Buick Roadmaster wagon that has similar front steering as the vans. In a turn as I turned the steering into the corner I would feel a point that the steering got easier to turn, just a slight oddity. I had no idea why and all the parts were new including a high end modification steering gear with better feel. That car needed more caster but the adjustments couldn't get there, so I cut apart the upper control arms and rewelded them back together to give the car more caster. With the increased caster the odd spot in turns went away completely. That makes me believe that as the wheels turn the caster changes depending on the design of the system. At some point the caster was going from positive to negative in the steering travel and that was what I was feeling. By adding more positive caster initially it made that point either go away completely or move to a spot that it didn't matter like only at full turn.


What you are describing sounds a lot like what I saw with the Buick, but on steroids. I think to get as much extra turning as you describe something may have to be loose and moving. Control arm bushings or bolts maybe. Upper control arm pivot bolts and cams may be broken or loose. Idler arms being loose is very common in the vans because many techs and owners miss the very well hidden upper grease fitting. There is an outside chance it could be rear steering also if it has a bad spring or shackle bushing but that rarely happens.



You have a 210 with aluminum wheels and are towing so you have the trifecta of stuff to be careful with.



210s are heavy to start out with because of the extended/larger coach section. The are something like 16" longer than stock so center of gravity moves toward the rear. Depending on how they are optioned, we have seen 210s mentioned that had barely 500# of load capacity before getting to max GVWR or overloading the rear axle if weight is placed too far back. Add a few hundred pounds of tongue weight hanging even further to the rear and you move the center of gravity more to the rear and add more than the tongue weight to the rear axle load. The front gets lighter with the more rear weight is hanging off the rear. This is why it is very important to get the axle weights, or even better the corner weights, on a 210, especially if it is towing.


The aluminum wheels are very likely to be zero or -6mm offset based on the ones folks have checked. Our 07 had different aluminum ones than yours and they were -6. Stock GM steel wheels that came on the vans are +28mm so with the aluminum wheels the tires move out nearly 1 3/8" at each wheel. This can mess up steering geometry and does put more load on all the wheel bearings, particularly in the rear if you have the standard non towing package semi floating design rear axle.


The rear axle max loading spec is basically the tire loading max spec of 6080# so it really means 3040# per side to protect the tires. The Roadtreks tend to have 2-300# more on the left rear than the right so you can see that you can have an overloaded tire even if you are within the axle limit. This is why corner weights get important.


Unless you are a relatively hardcore DIY mechanic, you do probably need to find a shop that is familiar with the light trucks. Pickups had nearly identical systems so an offroad shop might be a choice, or the previously mentioned trades/delivery type truck shops. They very possibly will be able to spot what is wrong, as what you see if very unusual for the Chevies, I think, as I can't ever recall your kind of issue being mentioned before.

[romeo]

“There is something really odd going on, for sure. Higher pressure should not but you into a severe over turning situation. I don't really think it is classic oversteer because that is lack of traction on the rear end.”

“The information that you saw about swaybars is correct even¬ if it is counter intuitive. They work backwards from how you would assume. Increasing the size or adding a swaybar to one end improves the traction of the other end. In your autocross example that meant getting both tires on road with more weight on them in the rear and the front bar did that. That means that adding a rear bar would improve understeer by improving the front traction. But that isn't what you have.”

Would’nt the wording IMPROVE UNDERSTEER mean “reduce understeer” which would move understeer in the direction of “oversteer”, as I would believe it to mean?

“You have a 210 with aluminum wheels and are towing so you have the trifecta of stuff to be careful with.”

“210s are heavy to start out with because of the extended/larger coach section. They are something like 16" longer than stock so center of gravity moves toward the rear. Depending on how they are optioned, we have seen 210s mentioned that had barely 500# of load capacity before getting to max GVWR or overloading the rear axle if weight is placed too far back.”[

I strongly believe that overloading is my problem or at least part of my problem since I don’t have it when I am not overloaded or towing. Again, I don’t really have any tongue weight. Pulling weight may have some effect.

“Add a few hundred pounds of tongue weight hanging even further to the rear and you move the center of gravity more to the rear and add more than the tongue weight to the rear axle load. The front gets lighter with the more rear weight is hanging off the rear. This is why it is very important to get the axle weights, or even better the corner weights, on a 210, especially if it is towing.”

As far as I know, I don’t have anyone that does corner weights here in the area. The only scales I know of are at the Pilot truck stop. With the motorhome I used DOT scales to get front and rear weights, which they did as a favor and unofficially. But at least I could find out how loaded the MH was. With the MH I would get corner weights when at a Rally, but don’t do rallies any longer.

“Unless you are a relatively hardcore DIY mechanic, you do probably need to find a shop that is familiar with the light trucks. Pickups had nearly identical systems so an offroad shop might be a choice, or the previously mentioned trades/delivery type truck shops. They very possibly will be able to spot what is wrong, as what you see if very unusual for the Chevies, I think, as I can't ever recall your kind of issue being mentioned before.”

Thanks for the things for me the think about. We are getting close to heading South so wont be able to get any results before we leave, so will have to endure the problem on the long drive until later, and I will have it to ponder all winter.
I appreciate you input.
Ron

[booster]

Originally Posted by romeo

Would’nt the wording IMPROVE UNDERSTEER mean “reduce understeer” which would move understeer in the direction of “oversteer”, as I would believe it to mean?

I strongly believe that overloading is my problem or at least part of my problem since I don’t have it when I am not overloaded or towing. Again, I don’t really have any tongue weight. Pulling weight may have some effect.

As far as I know, I don’t have anyone that does corner weights here in the area. The only scales I know of are at the Pilot truck stop. With the motorhome I used DOT scales to get front and rear weights, which they did as a favor and unofficially. But at least I could find out how loaded the MH was. With the MH I would get corner weights when at a Rally, but don’t do rallies any longer.

Thanks for the things for me the think about. We are getting close to heading South so wont be able to get any results before we leave, so will have to endure the problem on the long drive until later, and I will have it to ponder all winter.
I appreciate you input.
Ron

Terminology is always something that can mess up things
"Improving" in almost every case of our vans would mean reducing understeer even though a small amount of understeer is not bad to have for most vehicles. It is very difficult to get the vans to oversteer as they are so heavy in the rear and would probably roll over first.


If the problem is not happening when unloaded and not towing, you have a big chunk of the information you need to solve the problem. You do have tongue weight, but it is only 1/2 the weight of the towbar itself, I think. Does the towbar have antisway bars on it? I think those can push around the rear of the vehicle in turns if they are too tight. It certainly sounds like you are losing rear traction, probably from the van leaning a bunch and overloading the outside wheel. A big rear swaybar would probably help that a lot, and airbags in the rear could also, to a lesser degree. A Hellwig bar fits well if you don't have a generator. If you have a generator you would have to move it to the rear a few inches which was just done by a member on this forum and works fine. Most of the pickup truck guys I know say you have to have rear bar to tow well, and you don't have any bar in it stock.


Moving weight from the van and putting it in the Jeep might help, but may not also as we don't know exactly what is going on yet.

[romeo]

Originally Posted by booster

Terminology is always something that can mess up things
"Improving" in almost every case of our vans would mean reducing understeer even though a small amount of understeer is not bad to have for most vehicles. It is very difficult to get the vans to oversteer as they are so heavy in the rear and would probably roll over first.


If the problem is not happening when unloaded and not towing, you have a big chunk of the information you need to solve the problem. You do have tongue weight, but it is only 1/2 the weight of the towbar itself, I think. Does the towbar have antisway bars on it? I think those can push around the rear of the vehicle in turns if they are too tight. It certainly sounds like you are losing rear traction, probably from the van leaning a bunch and overloading the outside wheel. A big rear swaybar would probably help that a lot, and airbags in the rear could also, to a lesser degree. A Hellwig bar fits well if you don't have a generator. If you have a generator you would have to move it to the rear a few inches which was just done by a member on this forum and works fine. Most of the pickup truck guys I know say you have to have rear bar to tow well, and you don't have any bar in it stock.


Moving weight from the van and putting it in the Jeep might help, but may not also as we don't know exactly what is going on yet.

Does the towbar have antisway bars on it?
No, it's the normal tow bar used for this method of towing. I am familiar with the type of bar you are referring to since I had one years ago for my travel trailer.

If you have a generator you would have to move it to the rear a few inches
I don't have the normal generator; I have the underhood generator, i.e.: large alternator. That leaves off a lot of weight in the rear if the van and a big empty space in the chassis.

sounds like you are losing rear traction, probably from the van leaning a bunch and overloading the outside wheel.
And wouldn’t that tend to lift the front left tire, therefore, causing the left front tire to lose traction with the road surface and causing the steering to feel similar to “oversteer” or “light steering”; if not real oversteer? If that’s the case I can see where a rear sway bar would keep the front left tire down and give more traction to the front end.

I hope I thought that out properly since I was trying to think while fighting this damn forum software that logs me out and wipes out all that I’ve typed when I’m typing more than a sentence… MADNING !

[booster]

Originally Posted by romeo

Does the towbar have antisway bars on it?
No, it's the normal tow bar used for this method of towing. I am familiar with the type of bar you are referring to since I had one years ago for my travel trailer.

If you have a generator you would have to move it to the rear a few inches
I don't have the normal generator; I have the underhood generator, i.e.: large alternator. That leaves off a lot of weight in the rear if the van and a big empty space in the chassis.

sounds like you are losing rear traction, probably from the van leaning a bunch and overloading the outside wheel.
And wouldn’t that tend to lift the front left tire, therefore, causing the left front tire to lose traction with the road surface and causing the steering to feel similar to “oversteer” or “light steering”; if not real oversteer? If that’s the case I can see where a rear sway bar would keep the front left tire down and give more traction to the front end.

I hope I thought that out properly since I was trying to think while fighting this damn forum software that logs me out and wipes out all that I’ve typed when I’m typing more than a sentence… MADNING !

With no genny in the back, a Hellwig bar is great addition.


You are correct that a rear bar will level out the front end and impove traction on the front. But the suspension, front and rear, has enough travel to not leave the ground. Geometry will get messed up with on front wheel very heavy and other light and suspension compressed and extended on opposite side. The outside rear tire would the one that would be getting overloaded, even though in straight line is carry a bit less weight. The bar will move some of that weight to the opposite side of the van.


I think the cars you remember lifting a rear tire on hard corners would the early US front drivers like the Chrysler Horizon and Omnis and both were based on the VW rabbit. The reason they lifted the inside wheel was as the car leaned the rear wheels were essentially on a single pivot axis because they used a single trailing arm setup that made the wheels move up and down together minus the twist in the shaft. I had a 1978 Horizon and it was very easy to lift the inside tire in stock form is you had decent tires.

[romeo]

Originally Posted by booster

With no genny in the back, a Hellwig bar is great addition.


You are correct that a rear bar will level out the front end and impove traction on the front. But the suspension, front and rear, has enough travel to not leave the ground. Geometry will get messed up with on front wheel very heavy and other light and suspension compressed and extended on opposite side. The outside rear tire would the one that would be getting overloaded, even though in straight line is carry a bit less weight. The bar will move some of that weight to the opposite side of the van.


I think the cars you remember lifting a rear tire on hard corners would the early US front drivers like the Chrysler Horizon and Omnis and both were based on the VW rabbit. The reason they lifted the inside wheel was as the car leaned the rear wheels were essentially on a single pivot axis because they used a single trailing arm setup that made the wheels move up and down together minus the twist in the shaft. I had a 1978 Horizon and it was very easy to lift the inside tire in stock form is you had decent tires.

Back in the '60's autocrossers were primarily foreign cars and most all were sport cars. Now that I remember one of mine, should be the Triumph
TR-4, I found out was lifting the rear wheel a few inches off the pavement when I made a sharp, fast turn. I was told by a by-stander when I finished a run. Volkswagens in those days would roll over due to the transaxle and camber not keeping the wheels down in tight turns. The wheels would tuck under when weight was lifted and that caused the roll. A freind was in a cast for some time because he took a corner to fast in his beetle. Enough reminiscing...

I found a Truck and RV shop that seems to know about chassis and suspension work so plan to geo down and talk to them and see what kind of lifts they have available. I will ask the some investigative questions about sway bars and suspension.

[booster]

Originally Posted by romeo

Back in the '60's autocrossers were primarily foreign cars and most all were sport cars. Now that I remember one of mine, should be the Triumph
TR-4, I found out was lifting the rear wheel a few inches off the pavement when I made a sharp, fast turn. I was told by a by-stander when I finished a run. Volkswagens in those days would roll over due to the transaxle and camber not keeping the wheels down in tight turns. The wheels would tuck under when weight was lifted and that caused the roll. A freind was in a cast for some time because he took a corner to fast in his beetle. Enough reminiscing...

I found a Truck and RV shop that seems to know about chassis and suspension work so plan to geo down and talk to them and see what kind of lifts they have available. I will ask the some investigative questions about sway bars and suspension.

A TR4 lifting a rear wheel would be wicked unless you had a locked rear differential.


You must be referring to the old bug type rear drive VWs that just had a single U joint at the trans so a pure swing axle. On drop they tucked under and rolled them. The Corvair copied them and had the same issue, and they got sued big time on it and changed to normal independent rear suspension more like we see now to keep the wheel from tucking.


It will be interesting to see what the truck folks say!

[GeorgeRa]

Originally Posted by booster

A TR4 lifting a rear wheel would be wicked unless you had a locked rear differential....................

Wheels going up, sorry, I am going on tangent with an automotive question, do you know an old car which would allow a wheel to be changed without a jack? Please contribute if you know the answer.