Kodiak chassis suspension issues and fixes

[Roger H]

This thread will likely only be of interest to owners of motorhomes on Kodiak chassis coaches, although what I'll describe is applicable to all motorhome chassis.

In my research into improving handling on these chassis, there doesn't seem to be a definitive thread on how this chassis handles (other than folks complain about the handling) and what to do to tame them across any of the brand or general forums online. There are a series of issues I've identified and doing some pretty extensive online research, found piecemeal information that various folks have found piecemeal solutions to. I thought I'd discuss what I've come up with here; the problems my chassis exhibits, and the solutions I'm implementing in the hopes that someone else searching for those solutions will have one-stop answers to their issues as well.

I bought my '06 Born Free 32RQ on a Kodiak C5U042 chassis with the 8.1L gas engine and 4spd Allison trans in May of 2015. It had 32,200 miles miles on it. The front shocks had been replaced with Monroes and the rear shocks are stock. The tires were original equipment. The Ultra-Link Air-ride suspension works as designed and really give the coach a nice ride.

Driving the coach two hundred miles home on the interstate from the dealer proved to be "interesting." The steering can best be described as vague and the coach was nearly pushed out of the lane by passing trucks several times. Side winds affected the handling; sometimes dramatically. It requires constant attention to remain in your lane. Driving it requires constant attention, and is not for the faint of heart. After I got it home, I took it to my local tire dealer for tires and turned it around in a driveway with a curb-cut and a six inch difference between the drive and the street. Although I literally crept out of the drive at an angle into the street, the coach rocked violently pitching unsecured items to the floor, slamming the bathroom door open cracking the mirror, and generally throwing everything in the cabinets around. I've taken it now on two trips in the condition in which I bought it.

So, with about a thousand miles on my, I can say that the thing's handling can be best described as "uninspiring." It handles merely ok most of the time, with vague steering. It requires constant attention to keep it in the lane, especially in harsh side winds or when being passed. It isn't inherently "unsafe" but it doesn't inspire confidence in its handling at all.

Here are the issues that cause poor handling in these chassis: Cutaway motorhome chassis are sold with springs that ensure a nice, even and plush ride. Commercial chassis of the same model are sold with heavy spring stacks for heavy load carrying capacities. The only thing that keeps the axles centered under the body with a live-axle/leaf spring setup is the springs. When the spring stack is too weak to keep the load on the chassis from moving over the center of the axles, then bizarre things begin to happen to handling. The body is moving all over the place, trying to move the tire contact patch with it. The tires want to stay on the ground, and the difference in those inputs is what is felt by the driver while you try to keep the coach moving forward requiring constant steering input.

So, the key to ironing out the handling is to make sure the front end is tight and torqued to spec, keep the body and load centered over the axles at all times, and having shocks installed that are up to the task. Fortunately, there are several add-on after-market items that are built to do what is required. As a brief aside, I experienced these same issues when I was towing a 34' tri-axle Airstream with a Y2K Ford Excursion. The stock suspension wasn't up to the task there either as they'd softened the spring stacks considerably for ride quality. The solutions I found there are the same solutions that will be required for the Kodiak chassis motorhomes.

So, this is the full-monte solution... not all of these may be required for every coach, but i'm having them all added/done to mine:

1) Front end alignment and torque all nuts to specification: Apparently many medium duty trucks leave the factory with a wide-range of torque specs that are loosely followed, and a stable alignment is important to handling.

2) Replace all four shocks with Bilsteins or Koni. I tried to buy Bilsteins for all four corners, but the rear shocks are out of stock everywhere, so I have Bilstein fronts and Koni rears. If I had it to do again, I'd probably put Konis on all four corners.

3) Radius rods/trac bars: radius rods allow the axle to move up and down, but prevent the axle from twisting on the springs (called 'spring wrap') under a load. My coach already had a radius rod installed on the rear axle; I'm having a front radius rod installed as well.

4) Anti-sway bars: Anti-sway bars help keep the chassis load centered over the axle and help keep the load from traveling independently over the axle and dragging the axle along with it.

I have the shocks and front anti-sway bar and have an appointment with a local shot to have them installed early next week. I would have ordered the front radius rod and rear anti-sway bar and had them installed at the same time, but Roadmaster is currently out of stock on the rear sway bar, and the radius rod they offer apparently only fits the Duramax equipped version. Since I'll be making a trip to Portland, OR next month anyway, I have an appointment with Roadmaster at the factory in Vancouver WA in late August to install a rear anti-sway bar and to have the front Davis trac-bar fitted and installed. Roadmaster, Inc http://roadmasterinc.com/index.php customer service, so far, has been absolutely exemplary.

Since I'm having the shocks, front end alignment/nut torque checked, and the front anti-sway bar installed next week, and then driving out to Portland OR from Iowa, I'll be able to comment on the handling improvements over the stock equipment with those done... and then I'll have the front Davis trac-bar and rear anti-sway installed for the trip home, so I'll be able to report if there are any significant improvements in handling with those mods completed as well. One thing to note is that the Link Ultra-Ride air suspension that was installed on the 32RQ Kodiak chassis requires a special link bar (Roadmaster part number B315) for the Roadmaster rear anti-sway bar to install it on the Born Free Kodiak chassis.

Here is a link to the GM Upfitter's information for the '04 and up Kodiak chassis that provides all of the information from Chevy on the Kodiak chassis specs:
https://www.gmupfitter.com/files/media/ ... ctions.pdf

For reference, I've also uploaded and attached this .pdf to this post along with the owners manuals to the Link Ultra-Ride air suspension that was installed on Born Free coach chassis.

More to follow in late August. I hope someone finds this thread useful.

[jjhepkin]

Hi Roger
Sounds like you have quite a lot planned and I am sure you will notice an improved ride and handling after it is done.

Fortunately, the handling of our Kodiak unit has actually been better than the 24' Chinook we had before. The biggest improvement in the handling compared to the Chinook has been the steadiness when driving. We no longer feel the "blow by" when a semi drives past on the interstate (which happens continuously since we usually average 60 mph). So as a result, I can relax more now when driving than before.

I am guessing that the difference in handling between our 2 Kodiaks is the longer unit you have, 32' vs. our 28'. That extra 4' could account for your problems.?. The only thing we have done to our unit is adding Bilstein shocks all around which did help in handling the bumps and steadying those out.

We are beginning to have a problem with the air compressor for our Link air suspension. There is a leak somewhere around the compressor unit and it is cycling more and more frequently as time goes on. I will be taking it in to have it fixed locally (hopefully.)

Keep us informed and good luck to you. It will be worth it when you start enjoying the scenery on your drives instead of dreading starting it up.

john

[Roger H]

Hi Roger
Sounds like you have quite a lot planned and I am sure you will notice an improved ride and handling after it is done.

Keep us informed and good luck to you. It will be worth it when you start enjoying the scenery on your drives instead of dreading starting it up.

john

Thank you John!

I don't mean to imply that mine is un-driveable either, and I realize that my first post may make it sound like it's worse than it is. At 60 mph it's quite manageable. At 65 it begins to get kind of sketchy tho. At 65 in cross winds with passing trucks is when it starts to get into white-knuckle range... and that's at least partially a result of a lack of maintenance and having worn out rear shocks. The front shocks are more recent, but the Monroes are probably not the best shocks for this application, and of course they do little to dampen body roll in the back. I'm sure that having new, higher quality shocks all the way around alone will make a huge difference in the handling. Just having the new shocks and adding front anti-sway bar should improve the handling significantly, although the Roadmaster folks actually recommended adding the rear anti-sway bar first and seeing what that did. I'd have done that if I could have gotten one, but THAT is out of stock until they resume production as well... they said they'd have one built for me when I visit the factory next month. The only part I could get was the front anti-sway bar... so that's what I'm installing first.

I'd initially planned to do these upgrades one at a time until I was comfortable with the handling, but just finding rear shocks has been a real chore! That will ease up when Bilstein resumes production of the rears... but I've got the Konis for the rear now. So the five-week hunt for finding rear shocks allowed me to pursue the anti-sway bar and trac-bars as well... so now, I figure, "in for a penny, in for a pound." I'm planning on keeping this coach a very long time, so I decided I'd just do the full monte suspension mods off the bat and make it as comfortable to drive as possible.

I'll keep you posted on how the mods affect the handling. Actually I'm pleased that I'm getting only the shocks and front bar installed before I head West... that'll give me an opportunity to separately evaluate the efficacy of the added rear anti-sway bar and front Davis trac-bar on the trip home.

Roger

[Roger H]

One more thought, John... the Link Ultra-Ride http://www.linkmfg.com/contact/ airs suspension is another Iowa product... the factory is in Sioux Center which is probably why they (the chassis dealer, Fitzpatrick Chevrolet in Storm Lake, IA) installed that system initially on these Kodiaks. In any event, it's been my experience that most of these companies are very responsive to the service needs of their end-users should you have any issues getting your compressor or line-leaks repaired. So far the air suspension under my coach is doing ok... but I found the water blow-out valve and it blew out a lot of really rusty water when I used it. I'm not sure it's been used in a very long time, so I don't know how long it'll be until that needs service on my coach too.

Roger

[jjhepkin]

Actually I have called the Link customer service/technical dept. a couple of times. Their dealer network in the Denver area is not that strong and the dealers they have generally don't work on RV's. I did find an RV dealer who seems confident in fixing the problem.

The air release valve you mentioned is supposed to be used on a daily basis when traveling (according to Link anyway.) "Not releasing the moisture on a regular basis will cause the drain valve to not operate properly, and may cause the valve to malfunction. Excess moisture in the system can also cause premature failure of other components including the tank itself." That's quoted from their owners maintenance guide.

I wish I was closer to Iowa so I could take it into their shop.

John

[Roger H]

Actually I have called the Link customer service/technical dept. a couple of times. Their dealer network in the Denver area is not that strong and the dealers they have generally don't work on RV's. I did find an RV dealer who seems confident in fixing the problem.

The air release valve you mentioned is supposed to be used on a daily basis when traveling (according to Link anyway.) "Not releasing the moisture on a regular basis will cause the drain valve to not operate properly, and may cause the valve to malfunction. Excess moisture in the system can also cause premature failure of other components including the tank itself." That's quoted from their owners maintenance guide.

I wish I was closer to Iowa so I could take it into their shop.

John

Yes, I don't know how long the compressor tank had gone without being dumped, but now that I know what it needs, it will get the appropriate attention from me from now on!

If your RV dealer can't figure it out, I'd suggest one of the authorized GM medium-duty truck dealers in your area and see if they can give you a hand.

http://eogld.cloud.gm.com/NASApp/medium ... rlisttable

Roger

[Roger H]

Update 7/29/15

I had the front shocks replaced with Bilsteins and the rears replaced with Koni yesterday. The fronts were recent Monroes and probably didn't need replacing. The rears were factory stock and were shot. Interestingly though, the Bilsteins do seem to perform better than the larger-bore Monroes. I also had a front Roadmaster anti-sway bar installed. I drove the coach forty miles to a truck alignment shop. There was a big improvement in handling with the shocks and anti-sway bar installed. I'd put it about on-par with the handling of most of the off-the shelf motorhomes now.

I had the alignment checked as I've recently installed all new tires and I don't want them chewed up. As it was, the alignment was perfect, so no adjustments were made; however I asked that all of the front end nuts be torqued to spec, and three on one side and two on the other were not torqued to spec. A couple of them moved quite a bit. The steering seemed to be a little more precise on the 40 mile trip home. The coach is still affected by passing trucks, but not nearly as badly as it was pre-shock and pre-front anti-sway bar.

So, the coach is manageable now; the white knuckle ride seems to be over. I'm sure it'll benefit further from the rear anti-sway bar and Davis trac bar on the front axle. I'll report again after I have them installed next month.

[Roger H]

Update 9/3/15

I recently completed a 4,000 mile trip with the Kodiak chassis 32RQ. In the last post, I'd had the shocks replaced an a front anti-sway bar added. I towed a 19' travel trailer 1,700 miles from Iowa to Yakima WA with the coach with the front sway bar. The shocks and front sway bar brought the number of white-knuckle handling experiences down from three or four an hour to just a couple of them in a driving day. I delivered the travel trailer and continued on my drive from Yakima to Portland. The handling didn't change much from driving with the trailer in tow to not having it.

While I was in Portland, I took the coach to Roadmaster, Inc. across the Columbia River in Vancouver, WA where Wayne Wells installed the rear anti-sway bar and a Davis Tru-Trac bar on the front axle. The Tru-Trac had only been fitted to chassis with the Duramax, and Wayne had to make some minor modifications to fit it to my 8.1L gas chassis; the prototype gas chassis install.

I can only describe the difference in handling after those two items were installed as dramatic. I knew driving out of the parking lot that something was very different, and in a really good, solid way. The handling is so improved, I wondered where he'd hidden the coach I brought in! Just turning out of the parking lot, the coach didn't sway... and there was no steering input from the axles. It was amazing.

The remainder of the 2,000 miles I drove the coach on the return trip with the Roadmaster, Inc. suspension products installed were worry-free with NO white-knuckle moments at all. I found myself actually driving with one hand relaxed on the wheel... something that just wasn't possible before the suspension mods.

So, I'm a believer. The Kodiak chassis motorhome is VERY competent. I MUCH prefer it to the F450 chassis I had with under my '01 23RK; and with the suspension mods in place, it's a pleasure to drive as well. I can highly recommend Roadmaster, Inc's products and service as well.

If you're having steering input from your coach over the chassis, regardless of the make or model, install anti-sway bars front and rear... you won't be disappointed.


Keywords/search terms: Born Free Kodiak chassis 32RQ President motorhome Class Super C Four Winds Chateau Dutchmen Jayco Seneca Greyhawk Bigfoot Gulfstream Conquest Lazy Daze suspension RoadMaster anti-sway bar Davis Tru-Trac shocks

[funpilot]

So which Born Free models and years came with the Kodiak chassis or is it just simply those with Chevy engines?

[Roger H]

Born Free apparently made a 28', 30' and 32' on the Kodiak chassis from '06-'09. Chevy dropped production of the Kodiak in '09. The production numbers for the Born Free coaches on the chassis were relatively low... I have no idea how many of the 28RSB and 30' coaches were built, but Ed Newman wrote in another thread several years ago that there were about 16 of the 32RQ coaches like mine built during that time. Over the years, they've done Bed & Breakfasts, some custom coaches using the B&B body, and perhaps even some Built for Twos on standard Chevy van cutaway chassis.

[jeleuen]

Roger, You are the resident Kodiak guru. Have electrical problem with mine. Bath wall outlet doesn't work. In messing with it, two other outlets quit. The breakers in question are all 20 amp with push to test button. The breakers are all Cutter-Hammer. Probably same in your coach. In VA now and local dealers only have Siemens 20 amps, which different design on wires coming in. Any idea where to find the correct Cutter Hammer breakers? John

[Roger H]

Roger, You are the resident Kodiak guru. Have electrical problem with mine. Bath wall outlet doesn't work. In messing with it, two other outlets quit. The breakers in question are all 20 amp with push to test button. The breakers are all Cutter-Hammer. Probably same in your coach. In VA now and local dealers only have Siemens 20 amps, which different design on wires coming in. Any idea where to find the correct Cutter Hammer breakers? John

John, I think you have me confused with someone who actually knows something about these things!

Describe what "messing with it" means... were you just flipping the breakers, or did you go into the wall and remove the outlets? Or did you do something else?

I'm pretty clueless on electrical, I confess. The last problem I had was similar, but I'd run a 15 amp cord from a house to the 50 amp cord using a converter, and one leg of the 15-50 amp converter had come loose causing some outlets to have power and some not... it was really a strange deal. My buddy asked if I'd checked the cord. I thought... of course... and then thought again. I checked the cord and that's what I found.

I think my first call would be to the factory and see who they source them from. I'd imagine that they used the same electrical in these coaches as the E450 variety... you might do well to make a new thread about your issue too. Someone else may have the answer for you. Past that, the Great Google ("pay no mind to the man behind the curtain") is our friend. Good luck, and please let us know what you figure out.

[Fantom]

Sounds like you have somewhere in line GFCI outlet that has to be reset.
Look for one,