We're in Northern Minnesota on the Gunflint trail - Unbelievably beautiful up here. We went fishing and thouroughly enjoyed the time here so far. We leave on Saturday and onto a new adventure somewhere else. One question though - trip up here was a little nerve wracking 300 miles on some rougher roads. When Semi's pass I am white nuckling it. I am pulling a boat and when they come up they just about blow me off the road. I heard the stories about being blown around from a semi. I'm wishing I had some sort of steering stabilizer on it. One bothersome thing is when we hit a little bump it feels like the wheels are going to come thru the drivers and passenger seats. I have what looks like sumo springs on the coach but they are orange in color not that they do anything for bumps anyways. Can worn out shocks cause that loud bang. Springs wore out? Any ideas would be appreciated. 2004 (348) 8.1 Workhorse, 36 ft long. New tires all around.
Back for a Bit
- Thread starter RedsToy
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Arch Hoagland
Well-known member
I have a 36' Workhorse like your's and have no problem when trucks pass me. Actually mine is pretty stable.
All my suspension is stock. New shocks about 5 years ago for porpoising, the originals were worn out.
What pressure are your tires set to? I keep my 22.5 Michelins at 90lb all the way around which is 5lb over what is recommended by their tire pressure chart.
All my suspension is stock. New shocks about 5 years ago for porpoising, the originals were worn out.
What pressure are your tires set to? I keep my 22.5 Michelins at 90lb all the way around which is 5lb over what is recommended by their tire pressure chart.
Mark_K5LXP
Well-known member
Generally when you get pushed around by passing vehicles it's your back end that's loose. The axle is shifting side to side due to lateral movement of the leaf springs. A panhard bar is going to make the most difference and they're not horribly expensive. It's a bit unnerving when you first experience it on the road but I've resolved that my workhorse will never be a prevost, and I'm not going to throw $10K at it for a bunch of suspension gadgets trying. I've grown quite used to driving it on highways and interstates and it is what it is. I ended up having to replace my front suspension last year and as a result the ride got a bit smoother. Not sure which component contributed the most but I would start with shocks, they're not hard nor particularly expensive to change.
Mark B.
Albuquerque, NM
Mark B.
Albuquerque, NM
Kirk
Well-known member
That would sound like you have air bags so have you checked the pressure in them? If not that could well be a major part of the problem. There probably should be somewhere between 40# and 90# of air pressure in them.
Worn shocks can cause a lot of problems and if you have both bad shocks and too little pressure in the airbags, that could easily be the problem with the front ride.
My experience would agree with this but you could easily have some of both. You say that you are towing a boat but a Toad:Kia so are you towing both? If so that too could play a role in the handling problems.
Ex-Calif
Well-known member
Does your coach have front air bags and are they inflated properly?
If the coach front end "bottoms" once and then settles it is the load carrying capacity of the front springs/bags. If the coach rebounds 3 or 4 times after one dip it is 99% sure to be the shocks.
In regards to getting blown around by semis. They displace a lot of air. At first it seems scary but after a while and being aware they are coming you will probably be making unconscious corrections as they pass.
If the semi is passing on the left, I make a slight left correction as they cross my rear end as the side load behind the rear wheels makes the front go forward. As the semi passes the front it is the opposite as the side load on the coach is removed.
It takes a while to get used to traveling 70mph so close to a semi that you can touch it but that's what we live with.
If the coach front end "bottoms" once and then settles it is the load carrying capacity of the front springs/bags. If the coach rebounds 3 or 4 times after one dip it is 99% sure to be the shocks.
In regards to getting blown around by semis. They displace a lot of air. At first it seems scary but after a while and being aware they are coming you will probably be making unconscious corrections as they pass.
If the semi is passing on the left, I make a slight left correction as they cross my rear end as the side load behind the rear wheels makes the front go forward. As the semi passes the front it is the opposite as the side load on the coach is removed.
It takes a while to get used to traveling 70mph so close to a semi that you can touch it but that's what we live with.
Larry N.
Well-known member
When I read your problem, Red, my first thought was that it sounds exactly like what I experienced a number of years back in a brand new 34' Bounder (no toad, even) when my tires (especially the front ones) were set to a pressure that was too high. I learned, so after weighing the coach by axle, I set the tires to the tire manufacturer's recommended pressure for the weight, and it was never anywhere nearly that bad again.
Mark_K5LXP
Well-known member
I messed around with that a bit. I can tell a difference when they're completely full and completely empty but it's not like there's a night and day difference. GM put them in there for a reason and for the weight the only pressure to use is "max", so that's where I leave them. But having driven with full, half and zero I would consider airbag pressure to be the least of the contributing factors to ride and handling.
Mark B.
Albuquerque, NM
Ex-Calif
Well-known member
Mine deflated (punctured/worn out) and it was very noticeable on squat.
I replaced them and run them at 90psi. I don't think I have ever bottomed out when the bags were inflated but I know I did with them failed.
I agree with you that it would be hard to discern 60psi vs 90psi.
I also would posit that if one thing is bad there are other issues. When I got my coach I replaced shocks, steering damper, airbags, got new front tires and a wheel alignment.
Its my habit that if one thing goes in a vehicle "system" I change all of it as practicable to baseline the system.
Bobtop46
Well-known member
Your hitting the bump stop when you get the hard jolts. If you have air bags check them out, if not maybe add them.
Gary RV_Wizard
Site Team
According to the 2004 Challenger brochure, Red's 348 Workhorse model of coach uses the W20 chassis (20,700 lb GVWR) and therefore does NOT have airbags, front or rear. It's a 228" wheelbase, so barely long enough for a 36 footer, thus has a fair amount of rear overhang. With the boat swinging behind as well, I can imagine the bow-wave push of the passing semis is strong. First the boat gets pushed, pulling the rear of the coach sideways. Then the wave catches the back of coach again just as it starts to recover, twisting the front as the rear shifts sideways. Several seconds later, the wave eases of the back and pushes the front back the opposite way.
A panhard rod will reduce the swing somewhat, probably both rear and front axles would be of benefit from having them. Optimizing tire pressure for the actual loaded weight is also a key action. I don't think a steering stabilizer will have any effect on the push-pull of the semis, but might help peace-of-mind.
The shocks may well be tired on an 18 year old coach, even with the low miles. Since you say the coach is rebounding wildly (porpoising) on bumps, I'd change them.
A panhard rod will reduce the swing somewhat, probably both rear and front axles would be of benefit from having them. Optimizing tire pressure for the actual loaded weight is also a key action. I don't think a steering stabilizer will have any effect on the push-pull of the semis, but might help peace-of-mind.
The shocks may well be tired on an 18 year old coach, even with the low miles. Since you say the coach is rebounding wildly (porpoising) on bumps, I'd change them.
Kirk
Well-known member
In searching, I found this Workhorse Chassis Guide that does include the 2004, W20 chassis. On page 140 it has the following statement:
The deflection of the main springs are slowed and controlled by an auxiliary elastomer spring positioned between the frame and the axle. The auxiliary springs are multistage autothane units that do not require maintenance or adjustment.
It may be that this is what you are seeing and not air bags. Of course it is also possible that some previous owner replaced them with air bags or added air bags. In addition, on page 142 it states that Workhorse had a Stabil Air Suspension Kit available as an option that did add air suspension, so that is also a possibility. I suggest that you read pages 140 through 146 as they cover the entire front suspension of your chassis.
The deflection of the main springs are slowed and controlled by an auxiliary elastomer spring positioned between the frame and the axle. The auxiliary springs are multistage autothane units that do not require maintenance or adjustment.
It may be that this is what you are seeing and not air bags. Of course it is also possible that some previous owner replaced them with air bags or added air bags. In addition, on page 142 it states that Workhorse had a Stabil Air Suspension Kit available as an option that did add air suspension, so that is also a possibility. I suggest that you read pages 140 through 146 as they cover the entire front suspension of your chassis.
I crawled underneath and I looked again. The bags look orange but they are more faded clearish in color. Anyways they are pleated. If they are air bags I couldn't see any fittings on them to fill them. No air lines or anything. So, I'm not sure what they are for sure?
No, some other post said if it's porposing then shocks. It's not porposing, just bang bang bang when hitting potholes.
Thanks Kirk. I will.
This week we are pulling a boat. Some weeks will be the Kia. Depends on where we are going. I sure miss a car thou at sites where you might want to sight see the sites. But it's also nice having the boat where we can go out and fish and ride around. Can't have everything.
cully
Well-known member
thanks for the post/posts bringing the thought that the lunge forward and to the right push from a BIG rig that was passing on the left is the cause. The first few times that happened I was quite concerned. Now i plan for the "push" with my steering.
Mark_K5LXP
Well-known member
"Pleated" could be an airbag or it could be a "helper" spring like Sumosprings.
The sumosprings are a rubber compound, no air. I know my workhorse has something similar in the rear and are mostly for softening the impact of the axle on the frame. They have no effect on lateral spring/axle movement.
Mark B.
Albuquerque, NM
The sumosprings are a rubber compound, no air. I know my workhorse has something similar in the rear and are mostly for softening the impact of the axle on the frame. They have no effect on lateral spring/axle movement.
Mark B.
Albuquerque, NM
Laura & Charles
Well-known member
Over inflated tires can cause what you’re describing. Our first coach had horrible handling issues. After getting it weighed, we removed the 10 psi from the front and 5 psi from the rears and it made a world of difference.
