Wander on highway

[jjrbus]

Been experiencing some highway wander 0n my 02C200P, did not wander when I bought it with OE shocks and 10 year old tires. Put on new aftermarket aluminum rims and KYB shocks. A bit of wander so had it checked and front end given a clean bill of health. Took for front end alignment told me front end is tight, still that bit of wander. Thinking control arm bushings are worn but not worn out. Took back to alignment shop, great shop, old school. They found grease fitting that was dry. Greased it and gave me a clean bill of health, still wanders. I am thinking time for new control arm bushings.

Then I read what Booster posted about offset affecting handling. Can't be it but checked the net and my aftermarket wheels which I was assured mimicked the OE 8 lug Chevy wheels would be fine. So the aftermarket aluminum wheels are a 28mm offset and the OE steel wheels are 16-20mm offset. I had not thought of this before as the wheels look exactly like the OE chevy aluminum wheels, with a different offset.

Stopped and chatted with my alignment guru and he believes that the offset can cause the wander and thinks the only way to test it is to change wheels.

Have an appointment next Wed to get one more inspection\opinion on this.

Any input??

 

[booster]

Been experiencing some highway wander 0n my 02C200P, did not wander when I bought it with OE shocks and 10 year old tires. Put on new aftermarket aluminum rims and KYB shocks. A bit of wander so had it checked and front end given a clean bill of health. Took for front end alignment told me front end is tight, still that bit of wander. Thinking control arm bushings are worn but not worn out. Took back to alignment shop, great shop, old school. They found grease fitting that was dry. Greased it and gave me a clean bill of health, still wanders. I am thinking time for new control arm bushings.

Then I read what Booster posted about offset affecting handling. Can't be it but checked the net and my aftermarket wheels which I was assured mimicked the OE 8 lug Chevy wheels would be fine. So the aftermarket aluminum wheels are a 28mm offset and the OE steel wheels are 16-20mm offset. I had not thought of this before as the wheels look exactly like the OE chevy aluminum wheels, with a different offset.

Stopped and chatted with my alignment guru and he believes that the offset can cause the wander and thinks the only way to test it is to change wheels.

Have an appointment next Wed to get one more inspection\opinion on this.

Any input??

Have you tried swapping the tires and wheels from front to rear? If you got a bad tire and it is on the front you would feel it, but probably not if it was on the rear.


That offset change is only about 1/2" so probably shouldn't show up to a large extent unless it just happened to change the scrub radius to positive from being negative in stock form. That change will make the slack in tie rod ends and wheel bearings turn in instead of out from road force.


It is odd that you got +28mm wheels as replacements as those are pretty scarce in the marketplace. I think a 2002 would be the previous generation cutaway chassis so the current generation +28mm wheels wouldn't be to spec. Are you sure the new wheels are plus offset that far? They probably might be getting close to rubbing the inner fenders or front swaybar.


The stock wheels I could find for a 2002 Express are +28mm. Are you sure you have a 2002 chassis or is it built on a 2001 chassis? Roadtrek was often a year off when built from their van stock.

 

[jjrbus]

Thanks for the response, I am not sure of anything. These are the wheels I ordered and they show an offset of 28mm, Tried 3 other websites and they all show 28mm, for the new aftermarket rims. Are they all getting their specs from the same place??

On one site I did type in my info 01 Chevy cut away, 3500,
5.7, rwd, SRW etc and came back these wheels do not fit your application.

Some time ago I did rotate the tires front to rear and do not recall any change, may do it again this weekend for something to do. Now while I think about this the spare looks the same as the aftermarket wheels but was off a Chevy I need to take a look and see if it has the offset stamped on it.

https://www.amazon.com/Factory-Wheel-Replacement-1999-2010-ALY05079U80N/dp/B08DSHWWZB/?_encoding=UTF8&pd_rd_w=RnBPY&content-id=amzn1.sym.35cab78c-35e3-4fc1-aab0-27eaa6c86063%3Aamzn1.symc.e5c80209-769f-4ade-a325-2eaec14b8e0e&pf_rd_p=35cab78c-35e3-4fc1-aab0-27eaa6c86063&pf_rd_r=AF5XDNCBBYYS14Z5344B&pd_rd_wg=g8BdC&pd_rd_r=44d5ae4a-6064-4be0-9b90-2f4c5770fe5d&ref_=pd_gw_ci_mcx_mr_hp_atf_m

 

[peteco]

Been experiencing some highway wander 0n my 02C200P, did not wander when I bought it with OE shocks and 10 year old tires. Put on new aftermarket aluminum rims and KYB shocks. A bit of wander so had it checked and front end given a clean bill of health. Took for front end alignment told me front end is tight, still that bit of wander. Thinking control arm bushings are worn but not worn out. Took back to alignment shop, great shop, old school. They found grease fitting that was dry. Greased it and gave me a clean bill of health, still wanders. I am thinking time for new control arm bushings.

Then I read what Booster posted about offset affecting handling. Can't be it but checked the net and my aftermarket wheels which I was assured mimicked the OE 8 lug Chevy wheels would be fine. So the aftermarket aluminum wheels are a 28mm offset and the OE steel wheels are 16-20mm offset. I had not thought of this before as the wheels look exactly like the OE chevy aluminum wheels, with a different offset.

Stopped and chatted with my alignment guru and he believes that the offset can cause the wander and thinks the only way to test it is to change wheels.

Have an appointment next Wed to get one more inspection\opinion on this.

Any input??

I have no wander on my 2006 RT 210 with the wrong offset wheels. Agree that OE should be better but I have had no problem with mine.

 

[jjrbus]

I swapped the tires front to rear yesterday and made a difference on a short drive but something is still not right. Swapping tires wore me out, I am too old for this anymore. Nothing in the front end appears loose, will take it for an inspection wed.

Been reading about offset and those that study these things claim no more than 5mm offset change, I am at 8mm. Reading between the lines I am guessing they are referring to clearances more than handling.

Numerous web search's show that this wheel does not come in any other offset than a 28mm. I could of course have missed something.

I have seen this wheel on numerous Roadtreks and talked to one owner who has the same Roadtrek as me an 01, mine is a 02 on a 01 chassis. He does not have any handling issues. Here is a picture of his with the same wheel and towing a boat.

Thanks for the responses always greatly appreciated.

[/IMG]

 

[jjrbus]

This is a common 16 inch aluminum wheel for Chevy trucks in the 2000 years.

[/IMG]

 

[booster]

This is a common 16 inch aluminum wheel for Chevy trucks in the 2000 years.

[/IMG]

That is a +28mm pickup truck wheel.


https://www.hubcaphaven.com/p/955/a...ilverado-suburban-wheel-polished-9592555.html


Has anyone of the shops checked the toe. It has to be in, never out, to not wandering.

 

[peteco]

Have you had every component of the front suspension and steering checked? Tie rods, idler arm, pitman arm, steering box, ball joints, wheel bearings control arm bushings. I had a bad idler arm that the shop missed before doing an alignment.

 

[jojobafanzi]

Wander

Been experiencing some highway wander 0n my 02C200P, did not wander when I bought it with OE shocks and 10 year old tires. Put on new aftermarket aluminum rims and KYB shocks. A bit of wander so had it checked and front end given a clean bill of health. Took for front end alignment told me front end is tight, still that bit of wander. Thinking control arm bushings are worn but not worn out. Took back to alignment shop, great shop, old school. They found grease fitting that was dry. Greased it and gave me a clean bill of health, still wanders. I am thinking time for new control arm bushings.

Then I read what Booster posted about offset affecting handling. Can't be it but checked the net and my aftermarket wheels which I was assured mimicked the OE 8 lug Chevy wheels would be fine. So the aftermarket aluminum wheels are a 28mm offset and the OE steel wheels are 16-20mm offset. I had not thought of this before as the wheels look exactly like the OE chevy aluminum wheels, with a different offset.

Stopped and chatted with my alignment guru and he believes that the offset can cause the wander and thinks the only way to test it is to change wheels.

Have an appointment next Wed to get one more inspection\opinion on this.

Any input??

If alignment shop is telling you that your front end components are tight and you are experiencing wander that was not there before, you may want to play with the alignment. I'm not sure of your year Chevy, but my 2016 Chevy Express van was experiencing wander from day one. It was a miserable vehicle to drive and the alignment shops kept telling me the alignment was perfect and all components were tight. They were blaming everything else. At its worst, at 78 mph, I was bouncing off the armrests. Recently, I got the alignment shop to play with the adjustments and set the caster and tow to maximum recommended settings. The Chevy vans and some Dodge vans require this procedure. Just because something in a manual is there, doesn't mean it is perfect for your vehicle. These Class B's are modified, weight distribution varies and overall, suspension components wear and the vehicle responds to this wear. Not all vehicles wear and drive the same. My Class B is a 2016 RT Versatile 170. Hope this helps. Joe

 

[booster]

One thing that has not been mentioned is the tires. Are they load range E? What pressure are they inflated to? Normal to most of us is 65psi front and 80psi back. The vans are known to not handle as well, in most or our opinions, when set to what is probably on the door sticker at 50 psi front. If the tires were swapped front to rear when set at the sticker of 50/80 without adjusting the pressure. the wander might go away but the steering would feel weird because of the very high front pressure

We have gotten lots of questions about handling on the various class B vans over the years but this one is different. Not that it is more extreme or anything like that, it is that the offset problems have always been in the other direction as in having too little positive offset on the later Chevies do to Roadtrek and others putting -8 or zero offset aluminum wheels on them.

We have never seen anyone that had too much positive offset. I did confirm the nominal +18mm offset for the previous generations of vans like the one in question and also the +28mm for the later ones so all that information is correct. This may eliminate the possibility of it going from negative to positive offset so that is out as a cause, maybe, but not for certain because the van use different front wheel bearing designs, with the early ones using tapered roller bearings and later ones using unitized hubs with non serviceable bearings. The location of the wheels to bearings could be different. They also use different control arms so the ball joints aren't likely in the same place, and may be at a different inclination angle. Bottom line is that we really don't know the scrub radius for the van and the only way to see what it is would be to measure the wheel contact point change as the wheel turns, but that is beyond the capabilities of most of us. It is well known that a vehicle at or near zero scrub will wander, from what I have read.

Perhaps the OP would be able to test the scrub radius direction with what is a very odd way. Negative scrub radius vehicles will steer towards a one front wheel force but on them. Positive scrub radius vehicles will steer away from that same force. The best example of this is if you hit a pretty deep puddle with the right front wheel in a negative scrub radius vehicle you will feel the steering wheel try to turn to the right. If it is a positive scrub radius vehicle it will try to turn left.

This grease joint that may have never or rarely greased could be the clue to what Peteco pointed out as an issue with the front end. Likely it is the upper one on the idler arm which is hard to see. and get to. Those fittings appear to be missed a lot and the idler arm pivots do get loose on a lot of the Chevies over time.

Loose or too tight front wheel bearings has not been mentioned and should be checked (and probably serviced) as they are the old school style that need to be serviced and regreased regularly. They are also adjustable and I think there are many younger people who have never dealt with adjustable front bearings.

But, and it is a big but (no pun there), is that all this started with wheel/tire/shock changes.

Swapping the tires and it is said to have made a difference, but something still odd. Details of what changed and what didn't would be good to know, I think.

Going more positive on the offset might slightly soften the spring rate and lower the van.

The KYB shocks tend to be on the stiff side in general, although I have never had them on our van, so can't speak on that particular part number. I have used them in numerous other vehicles and they are very good shocks with quite high gas pressure in the ones I had. The higher, probably, gas pressure in them will raise the van slightly and slightly change the front end settings. New and better shocks often will improve steering response, though, and you always have to be aware that steering corrections might be smaller because of the improved response. If you are used to larger responses, you need to retrain yourself to smaller ones because the corrections are mostly don't without you thinking about it. If you are constantly overcorrecting, you can perceive it as wander, but it is induced by you not the vehicle.

A good thing to know would be how much the steering wheel is moving to correct the wandering. That would give an idea of how loose the front end is and how responsive the steering is.

 

[booster]

If alignment shop is telling you that your front end components are tight and you are experiencing wander that was not there before, you may want to play with the alignment. I'm not sure of your year Chevy, but my 2016 Chevy Express van was experiencing wander from day one. It was a miserable vehicle to drive and the alignment shops kept telling me the alignment was perfect and all components were tight. They were blaming everything else. At its worst, at 78 mph, I was bouncing off the armrests. Recently, I got the alignment shop to play with the adjustments and set the caster and tow to maximum recommended settings. The Chevy vans and some Dodge vans require this procedure. Just because something in a manual is there, doesn't mean it is perfect for your vehicle. These Class B's are modified, weight distribution varies and overall, suspension components wear and the vehicle responds to this wear. Not all vehicles wear and drive the same. My Class B is a 2016 RT Versatile 170. Hope this helps. Joe

You are lucky in a couple of ways, most of which is to find someone who can actually get decent settings, and also that you can get that much positive caster. Our van is maxed out on the right side at 3.5* and it will take some semi major work to get more.

The settings you got are quite good, IMO, but one thing you may want to keep an eye out for is excessive wear on the outside edges of the front tires. If the front end really is nice and tight .27* is very high as I think that converts to a bit nearly 5/16" in the older inches scale. Normally I would say as low as 1/16" for a very tight front end and 1/8" for broken in one. 1/4" for one getting sloppy. More toe in normally means more stable tracking, but you have to watch for high edge wear on the front tires.

The Chevies at normal ride height (yours may be lower if it is a B and has not been lifted back up to stock height) is camber progressive on compression. This means that the camber gets more positive as the wheel is pushed up be bumps or cornering forces. On most vehicles set up this way the camber changes to negative once the wheel move high enough for upper control arm to go past horizontal. Some people can feel that transition in the feel of the steering wheel and others don't notice it so it is small. If you are lower than stock, which is probable, you may already negative progressive (I think that is good) or very close to it. That is why the Chevy spec is to align a bit positive to make it stay positive on compression.

 

[jojobafanzi]

Been experiencing some highway wander 0n my
Any input??

You are lucky in a couple of ways, most of which is to find someone who can actually get decent settings, and also that you can get that much positive caster. Our van is maxed out on the right side at 3.5* and it will take some semi major work to get more.

The settings you got are quite good, IMO, but one thing you may want to keep an eye out for is excessive wear on the outside edges of the front tires. If the front end really is nice and tight .27* is very high as I think that converts to a bit nearly 5/16" in the older inches scale. Normally I would say as low as 1/16" for a very tight front end and 1/8" for broken in one. 1/4" for one getting sloppy. More toe in normally means more stable tracking, but you have to watch for high edge wear on the front tires.

The Chevies at normal ride height (yours may be lower if it is a B and has not been lifted back up to stock height) is camber progressive on compression. This means that the camber gets more positive as the wheel is pushed up be bumps or cornering forces. On most vehicles set up this way the camber changes to negative once the wheel move high enough for upper control arm to go past horizontal. Some people can feel that transition in the feel of the steering wheel and others don't notice it so it is small. If you are lower than stock, which is probable, you may already negative progressive (I think that is good) or very close to it. That is why the Chevy spec is to align a bit positive to make it stay positive on compression.

Thank you for your response. I really appreciate the input. My Chevy is set up the way Roadtrek built it except for the Michelin tires and Bilstein shocks. Originally, the vehicle was towed out and tires were wearing on the inside. I'm not too concerned with tire wear as I am with keeping the vehicle on the road and having the ride comfortable. Before the tech played with my caster, long drives were exhausting. The vehicle seems level to me. I had the vehicle weighed so I know the weight of each axle. Tire manufacturers website has the charts for the proper tire pressure. This is my second Class B. I had to part with my beloved 97 Coachmen due to age and corrosion. The Versatile 170 is shorter and I miss the extra length but this newer model is better in many ways. I think I now have all the factory defects repaired. LOL!

 

[TX-Trek]

Assuming all components are in good shape as you've mentioned, the biggest improvement to resist that wandering in our 2010 210P was 65/80 tire pressures, a very slight adjustment to the steering box and slightly tightening up the toe adjustment.

I think also that the new higher lift front springs, front Sumo bumpers and Airlift bags in the back help tremendously with back to front porpoising and no more crashing over overpass expansion joints.

No weird tire wear , goes down the road nicely.
If I remember right, we brought toe-in "in" by 1/16 degree each side. I'll have to double check - way back sometime Booster had posted info on alignment criteria.
Steering gear adjustment was to the allen fitting at top of steering box, slight tightening of the gear shaft. By slight I mean about 1/16 turn in our case.

Also be very sure you've verified no play at either end if the steering drag link. Often easy to miss.

 

[peteco]

Thank you for your response. I really appreciate the input. My Chevy is set up the way Roadtrek built it except for the Michelin tires and Bilstein shocks. Originally, the vehicle was towed out and tires were wearing on the inside. I'm not too concerned with tire wear as I am with keeping the vehicle on the road and having the ride comfortable. Before the tech played with my caster, long drives were exhausting. The vehicle seems level to me. I had the vehicle weighed so I know the weight of each axle. Tire manufacturers website has the charts for the proper tire pressure. This is my second Class B. I had to part with my beloved 97 Coachmen due to age and corrosion. The Versatile 170 is shorter and I miss the extra length but this newer model is better in many ways. I think I now have all the factory defects repaired. LOL!

I'm going to throw this debatable topic into the mix, and I am not sure it would necessarily apply to wander: sidewall stiffness. GM specs a speed rating "S", along with Load Rating "E". The speed rating typically affects the sidewall stiffness, but not necesarily all the time. The Michelins are typically an "R" rating, one step lower than S and with less stiff sidewall. Hence the renowned "soft ride" from Michelins. There is a potential price to pay though, and that is with handling, as a softer sidewall will permit more sidewall deflection when the tire is loaded laterally as in a turn, side wind, or perhaps with wandering. Again, various views here. Note also that a combination of two or more smaller things could be adding up to cause your problem, which makes it tougher to solve. Here is further discussion on the speed rating.

https://www.classbforum.com/forums/f5/tires-on-chevy-class-bs-load-and-speed-rating-spec-7686-2.html

 

[booster]

Thank you for your response. I really appreciate the input. My Chevy is set up the way Roadtrek built it except for the Michelin tires and Bilstein shocks. Originally, the vehicle was towed out and tires were wearing on the inside. I'm not too concerned with tire wear as I am with keeping the vehicle on the road and having the ride comfortable. Before the tech played with my caster, long drives were exhausting. The vehicle seems level to me. I had the vehicle weighed so I know the weight of each axle. Tire manufacturers website has the charts for the proper tire pressure. This is my second Class B. I had to part with my beloved 97 Coachmen due to age and corrosion. The Versatile 170 is shorter and I miss the extra length but this newer model is better in many ways. I think I now have all the factory defects repaired. LOL!

Don't go by the tire manufacturer's recommended pressures, IMO. Those are setup to be the minimum tire pressure required to be safe at the max load on the tire. They don't address handling at all. The 65/80 is pretty universal on Roadtreks as long as they are load range E tires. We have had members here that were given lesser rated tires by the tire shop so always be aware.


What are yours currently set at?

 

[jojobafanzi]

Don't go by the tire manufacturer's recommended pressures, IMO. Those are setup to be the minimum tire pressure required to be safe at the max load on the tire. They don't address handling at all. The 65/80 is pretty universal on Roadtreks as long as they are load range E tires. We have had members here that were given lesser rated tires by the tire shop so always be aware.


What are yours currently set at?

I'm currently running 42psi and 64psi on load range E michelins. Any more than that and I can feel the shock of road bumps. At 15,000 miles, the tires are wearing perfectly. I'm aware of over-pressured tires having less tread on the pavement; Not desirable. I am very happy that there is this Forum with so much experience that is being shared. You mentioned that I am lucky to have a skilled tech set my steering alignment. I really feel that I am lucky to have a alignment tech go outside the box and make the adjustments to make the vehicle drive like it is supposed to. I feel that the factory recommended settings are just that, recommended. In reality, one must get in the vehicle and drive it and address the symptoms, the performance, handling and comfort. Vehicles, especially two stage vehicles are not an exact science. I remember my grandfather teaching me that the cars he worked on back in the day were nothing more than horseless carriages with an aftermarket kerosene engine attached. I have been involved in building rock crawlers; Nothing we did was absolute or considered factory specs. We were and are the test lab for many vehicles being produced today. There is so much lost knowledge and experience it drives me crazy at times.

 

[booster]

I'm currently running 42psi and 64psi on load range E michelins. Any more than that and I can feel the shock of road bumps. At 15,000 miles, the tires are wearing perfectly. I'm aware of over-pressured tires having less tread on the pavement; Not desirable. I am very happy that there is this Forum with so much experience that is being shared. You mentioned that I am lucky to have a skilled tech set my steering alignment. I really feel that I am lucky to have a alignment tech go outside the box and make the adjustments to make the vehicle drive like it is supposed to. I feel that the factory recommended settings are just that, recommended. In reality, one must get in the vehicle and drive it and address the symptoms, the performance, handling and comfort. Vehicles, especially two stage vehicles are not an exact science. I remember my grandfather teaching me that the cars he worked on back in the day were nothing more than horseless carriages with an aftermarket kerosene engine attached. I have been involved in building rock crawlers; Nothing we did was absolute or considered factory specs. We were and are the test lab for many vehicles being produced today. There is so much lost knowledge and experience it drives me crazy at times.

Actually, I was wondering what the OP's pressures were at because of the new tires and the problems.


But, your pressures are as low as I have seen, even for a 170 Roadtrek. I think you have an 8600# gross weight?



I would expect you to get good ride comfort, but I wonder about stability and tracking with them that low.


Do you monitor your tire temps?

 

[jojobafanzi]

Actually, I was wondering what the OP's pressures were at because of the new tires and the problems.


But, your pressures are as low as I have seen, even for a 170 Roadtrek. I think you have an 8600# gross weight?



I would expect you to get good ride comfort, but I wonder about stability and tracking with them that low.


Do you monitor your tire temps?

I bought the vehicle in South Carolina and drove it 800 miles to home. It was a miserable drive and the vehicle made me sick. I tried every tire pressure from 40 to 80psi and nothing changed other than high pressures making the cabinetry rattle. The axle weights are 3700# and 4760# Loaded with persons, gear and all fluids as we travel. Handling is good. No dodging on road seams and the vehicle tracks straight. I don't monitor tire temperature; I'm not sure how to do that? Do you mean with a non contact thermometer? I tried air bags in the rear but removed them as all they did was make the ride hard. One of the improvements I made was good shocks. That greatly improved the handling. The most difficult part of owning this Class B has been listening to the same old line from the auto shop that the front end is tight, the alignment is perfect and "I don't feel what you are claiming you feel when I drive your van, It feels perfect to me". That drives me crazy. I don't own a lift and it was so difficult to get the alignment tech to change the adjustments. Sigh!

 

[jjrbus]

I have had trouble posting on this site due to site logging me out. This time after posting a long response the post disappeare, it posted, I saw it! I have copied post before posting, now I changed a setting so clip board will save items placed on it.

Thanks for the input. Tires are Bridgestone LT VSteel rib 245 75R 16 load range E, This tire has a S speed rating. After buying I found they were the OE tire for my 02 Roadtrek 01 chassis. I believe too many tire failures are due to underinfaltion and am anal about psi, using TPMS and carring a compressor, I will not drive 10 feet on an underinflated tire. They are now 2 years old with 7000 miles on them. I consider 10% under recommended pressure to be underinflated. I need to weight this.

I do try to exercise the tires regurally, the low milage and wander being subtle does not let me decide something is a problem right after doing. When I greased the van I missed the grease fitting for the upper idle arm driver side. That caused a very noticeable increase in wander. VAn had been in paint shop for 3 months, I took it to have alignment checked and they found the ungreased fitting after greasing there was a noticeable improvement. I had 2 oil changes at lube places and the van inspected twice and no one greased it or mentioned it needed grease! Missing the grease fittings makes me wonder what else they missed!

I am experimenting with front tire pressure, tried 50, then 55 with no noticeable difference. Somehow misread the # and drove with 58 psi. Windy but at 58 did seem different. Will play with it a bit more.

This is dry season in FL so unlikely I will be able to do the wet scrub test.

I have complete confidence in my alignment shop, at their old location my Toyota RV would not fit so they alignded it in the parking lot! Still I have an appointment wed at another shop to have the front end checked, even the best can miss something! In the mean time I will be watching for a set of wheels with the correct offset to test that theory.

I need to watch for how much play in the wheel and report back. Would it be worth having the tires balanced to look for issues? I think I get a free balance at Discount tire.

 

[jjrbus]

Talking about tire you may find Roger interesting.

https://www.rvtiresafety.net/