Class C Suspension / Handling Issues - Next steps?

[BrunoMTP]

Greetings All,

Having read many of the posts and articles here and also watched numerous Youtube videos, have attempted to improve the handling characteristics of a somewhat recently acquired 2007 E450 / Fleetwood Tioga 26Q. Issues noted are as follows:

7 year old tires, good tread, even wear, only replacing due to age

1) Loose Steering
2) Wandering steering at highway speeds
3) Pushed around by passing cars, more by passing SUVs, much more by passing trucks, and gusty winds even more!

Steps taken thusfar are as follows:

New Tires (Yokohama, P225/75/16 Load E, 2450 PSI dual, 2680 PSI single rated)

Bilstein Steering Damper added - Caused the front end to pull to the left. Removed and replaced with another OEM Steering Damper (the slightly beefier Monroe Steering Damper did not fit due to the boot flange at the bottom)

Weighing Vehicle at Cat Scales fully loaded (Individual wheel weighing not readily available)
- Front Axle Weight 3600 actual, 4600 Rated, Tire pressure set to 60PSI
- Rear Axle Weight 9400 actual, ~ 9600 Rated, Tire Pressure set to 80PSI (Max)

Alignment - Took to a local Los Angeles RV / speciality shop for the + Caster Fix suggested by Harvard and others and was told that the alignment was spot on at 0 toe, 0 camber, 3.5 Caster. As part of the alignment they did center the wheel (which was slightly off) and tighnened the steering gear box. Was told that replacing the Caster bushings with adjustable ones and increasing the Caster would cause the front end death wobble problem, but they would do it if I wanted them to, and that I needed a bunch of other upgrades - to start off with:

Sumo Springs Front (Black, 1000lb)
Sumo Springs Rear (Yellow, 2800lb)
Roadmaster Rear Anti-sway bar upgrade

This would run close to $2K for parts and labor

The Sumo Springs looked simple to install, so despite some misgivings about the shop's "Advice". I went ahead and replaced them myself and did a test run up to Las Vegas for the weekend, with plans to upgrade the Anti-Sway Bar in a couple of weeks. While the Sumo Springs did firm up the suspension and helped a little with items #2 and #3 above, the ride quality really suffered. I felt like the RV and I were being beaten to death by every road imperfection. Am planning to remove the rear Sumos (at least), and maybe replace the front Sumos with the Blue 500# ones, but am now in a quandary on how to proceed further...

Am looking at the following possibilities:

Find a different shop to do the Caster upgrade or do it myself.
Upgraded Rear Anti-sway Bar
Add Track Bar for the rear
Air shocks

Help!

As an aside, on a long since retired 82' Jamboree 24D E350 that presumably had significantly less rear weight, I installed Air Shocks and was able to increase the rear height ~ 2 inches by adjusting the air pressure and firm up the ride / handling with minimal harshness. Is something like this an option or are air bags the newer alternative for rear heavy rigs?

On the 82' Jamboree 24D, the front and rear wheel well heights to the top of the tires are 4.5 inches each with the air shocks
On the 07' Tioga 26Q, The front wheel well height is ~ 6", the rear wheel well height is ~2", but the interior is basically level - as if it were designed to sit on the Chassis this way.

 

[donn]

First thing IMHO your tires are way underrated.
Second what is your rear overhang? Very typical class Cs have a lot of rear overhang, which can create weird, read that horrible, handling characteristics. Third, load? Unload anything behind the rear axle and see how it behaves.

 

[RRR]

I had an 2007 Sunseeker DS 2860 about 30' plus a few inches, bought used. First think I did was get the tires properly inflated, 80 rear and 65 or 70 for the front. Really settled things down.

Replaced the front sway bar with a Hellwig, got a large improvement. So much that I added one to the rear the next month.

Then had it aligned. I'm lucky that I got a guy my age that has been doing wheel align since oxen pulled carts. He knew exactly what needed to be done. I think he said he got about 4° and tried that. Never looked back.

My fresh water tank was in the rear and I tried to travel with 1/4-1/2 full depending on destination and anticipated needs. Was always 400-800 over on the rear but with burning off the gas and water usage I made do.

BrunoMPT Look at four front sway bar. Does it go into the A_Frame with a couple of bushings? It is a poor design IMO. Mine had no rear bar. Look at Search Results | SD Truck Springs | Leaf Springs, Helper Springs and Suspension Parts and see the size difference. Both can be installed by a competent DIY with basic tools and a couple of beers.

Excellent customer service from SD and Hellwig. I had to call Hellwig when I couldn't figure out something on the front bar. The gentleman I spoke with set me straight in 15 seconds. The light slowly dawned, and we had a good laugh at my expense.

SD used to give you like 5% if you called them and asked them a question. "I can sell you this now for $xxx if you order now."

 

[BrunoMTP]

First thing IMHO your tires are way underrated.
Second what is your rear overhang? Very typical class Cs have a lot of rear overhang, which can create weird, read that horrible, handling characteristics. Third, load? Unload anything behind the rear axle and see how it behaves.

Hi Donn - I should have elaborated more on the tires...

2680# max * 2 for the front would be 5360# Max for the front tires at 80 PSI. Axle Rating for the front is 4600# max, and actual weight is 3800, so pressure reduced as per inflation chart to 60PSI for lower load on the front tires.

2450# max each tire (for Duallys) * 4 =~ 9800# Max for the rear tires, Rear Axel Rating about 9600# (slightly less actually, don't have the spec in front of me), so Tires inflated to max 80 PSI.

I'll see what I can do about load re-balancing. Considering mounting a front hitch and rack to move some of the weight (Bicycles) from the rear to the front. Thank you for you comments.

 

[Tom55555]

Get your RV weighed and adjust your tire pressure accordingly. I had a Roadmaster rear sway bar installed which helped.

 

[Kirk]

I did some digging on specs for your Tioga and my source lists the rear axle rating as 9450, which would mean you are right at the maximum for it, as well as very tail heavy. But the more critical balance factor is side to side and if you are more than 10% difference that is likely a major part of the handling problem. On the rear of the RV the weight is multiplied by the distance behind the rear axle so even a relatively small weight moved from the rear bumper to the front will make a difference.

 

[crawford 111]

I have one and the the best money spend was the heavy duty sway bay in rear took off the ford one and put on the monster compared to old one. was able to drive with one hand with no problem. The problem was the rear over hang that did that job. Tire's never helped I did change them because of rear blow outs to G that gave me about 2 inches of height in rear which was great. That tire gave me piece of mind each was able to give 1,000 pounds per tire extra cap.

 

[Harvard]

OP has a text book example of having too little caster.

 

[BrunoMTP]

I did some digging on specs for your Tioga and my source lists the rear axle rating as 9450, which would mean you are right at the maximum for it, as well as very tail heavy. But the more critical balance factor is side to side and if you are more than 10% difference that is likely a major part of the handling problem. On the rear of the RV the weight is multiplied by the distance behind the rear axle so even a relatively small weight moved from the rear bumper to the front will make a difference.

 

[BrunoMTP]

Thanks Kirk - Am still looking for a place to weigh each wheel individually to re-balance the load better - When I weighed the rig it was under a worst case scenario - Full Fresh, Grey, and Black water tanks (about 800#) and also loaded with all of our stuff for a trip.

For the general Front-to-Back balancing have ordered a front Draw-Tite hitch to move the bicycle(s) and hitch rack from the rear to the front to utilize some of the additional capacity there and reduce the load on the rear.

Have also moved some of the gear from the rear cargo bay to the "chase" car that we take on our trips (Not Towed) to reduce the tail weight overall.

 

[BrunoMTP]

Have ordered the Hellwig 7180 to replace the OEM Rear Sway Bar. In the meantime, are there any recommendations for shops in the SoCal area for doing the caster fix? If not I'll plan on doing it myself in the not-to-distant future if the upgraded Rear Sway bar isn't sufficient to tame the beast.

Also, what's the thinking on Air Lifts vs Air Shocks vs ?? My current thinking is that Air Shocks are a less expensive and involved means of slightly firming up the ride than Air Lifts + OEM Shocks or Air Lifts + Koni shocks. Opinions?

 

[s.lange]

Have ordered the Hellwig 7180 to replace the OEM Rear Sway Bar. In the meantime, are there any recommendations for shops in the SoCal area for doing the caster fix? If not I'll plan on doing it myself in the not-to-distant future if the upgraded Rear Sway bar isn't sufficient to tame the beast.

Also, what's the thinking on Air Lifts vs Air Shocks vs ?? My current thinking is that Air Shocks are a less expensive and involved means of slightly firming up the ride than Air Lifts + OEM Shocks or Air Lifts + Koni shocks. Opinions?

BrunoMTP
Just came across your thread and was wondering how is it going on the suspension and handling improvements.
I cringed when you posted about the specific relative hardness of the SUMO Springs products you mentioned as I had a bit of the same reaction from my initial rear SUMO but got it straightened out to what I was after. I have a 2007 27ft Forest River Lexington and I put the softest SOLO product (bump-stop replacement) on the front. Elated at the smoother & softer ride and quieter reaction to bumps. I put the MAXIM product (bolted to frame and axle) on the rear, and due to the rear's weight, the suggestion was to use the medium "-47" hardness inserts. Resulting ride was too hard or harsh and absolutely not what I was after. Henderson's Line-Up in Grants Pass, Oregon and SuperSprings in Carpenteria, Calif both suggested we swap out the "-47" medium SUMO insert for the softer "-40" insert. The change worked beautifully with the coach running smoother and the noise level dropped more since not so much road jarring was being sent into the vehicle.
The SUMO SPRINGS were just part of the handling improvements made to the used 2007 MH. We also added f&r KONI FSD, f&r Hellwig HD anti-sway bars, and SuperSteer SS450 rear Trac Bar.
I have Harvard's Ingall's 594 adjustable alignment bushings but I've completely failed in finding a shop that will strive for the 5* and 5.5* caster target (even using their choice of replacement bushing) so I'm studying up on the pre-circa 1990's laser & computer controlled alignment dependency and planning on spending $200-$300 on my own tools and do my own work. I do have a Porsche mechanic friend that might loan me a measuring tool or two for the initial effort. Those tools go to the competition events - how can they possibly get field alignments right without a $250,000 Hunter Alignment machine? I'll be seeing him about my plans with shopping examples from online suppliers and get his advice.
On a side note: historically I know posters have given up on begging commercial shops and followed Harvard's example: Set both 594's for max +2* caster and 0* camber, install them properly, set the toe and enjoy the change. I may just do that, and after a week, take a digital level and check the camber if the unknown is bothering me.
Hoping all is well with you and yours. Safe traveling.
Steve

 

[BrunoMTP]

It's been awhile so I thought I'd update - Installed the Hellwig rear anti-sway bar, the front hitch, and just recently a pair of Koni FSDs on the rear. While the front is a bit springy, it's okay with the sumo springs now that they've broken in. The rear is still way too firm and am hoping the Koni FSD's will help. If not, then will pull the sumo springs and replace with softer ones, air bags, or the original bump stops.

Shout out to Kirk for the front / rear leverage loading advice - Did a 2k mile trip with about 250#'s of extra weight on the front via the added front hitch/rack and what a difference! It really settled the front end down and also reduced the wander.

Have the adjustable Caster bushings in hand and found a place in Las Vegas, NV that said they install these all the time - A Arrow Alignment. It's on the todo list for the next time I'm in Vegas.

 

[s.lange]

BrunoMTP,
Good to hear you're making progress.

I don't about you and your MH, but I was a tad shocked to learn mine was basically at its rear weight limit with just full fuel and 3/4 tank fresh water. But it did tell me it's first 43K miles put the rear axle components, especially leaf springs, through a lot. So much so that the rear leaf spring bushings were squishing out and I had them replaced. That was an ordeal as both the grey and black water tanks had to be removed, or, as my Porsche mechanic friend suggested, have the rivets attaching the brackets (for the rear of each spring) to the frame removed to lower the axle assembly for the new bushings. Somewhat standard practice when necessary and the brackets are bolted back to the frame upon reassembly with bolts engineered for this purpose. I did find a shop that had done this before. In hindsight maybe I should have installed new leaf springs then.

On the SUMO SPRINGS:
You're running the bump-stop replacement -47 yellow 2800# rear SOLO, and considering the -47 1500# rear SOLO.
I'm running the MAXIN product. Initially started with the -47 5000# insert, found the result to be too firm for my suspension* and swapped them out for the softer -40 3000# insert with very satisfactory results for me.
*My suspension's springs may be far weaker than yours and even though we are both running nearly the same SUMO spring # rating (your's @ 2800#, mine @ 3000#), your ride is stiffer than mine with the same 9400-9600 lbs on the rear axle. You may find the 1500# SOLO product to be fine. I'm assuming if I were to install new OEM leaf springs my ride would stiffen.
Certainly worth a phone call to Super Springs to discuss and possibly drive up the coast to Carpenteria and visit the facility. As a "customer with an issue", as I was, they may have ideas/solutions for you. Maybe there's a loaner set of the softer ones for you to try just to experience the difference. They invited me to come if I was so inclined. Make a camping trip out of the adventure and overnight or longer along the ocean on the old Hwy101 frontage south of Carpenteria.
There's also the potential problem of having too much spring. Maybe a 500# SOLO would work but SS no longer offers that which I think(?) they did early on. With your new Hellwig HD anti-sway bar and the KONI's along with your original bumpstop you may be done or add the airbags whose resistance can be moderated.
Reminds me of the scenes from 'The Good, The Bad and The Ugly' movie where Tuco is piecing together just the right components for the best pistol which later led to Blondie's quote: "Every gun has it's own tune" - at least that's one interpretation, the other being Tuco's preferred shooting cadence.

Good luck with this endeavor.
Steve

 

[Kirk]

Did a 2k mile trip with about 250#'s of extra weight on the front via the added front hitch/rack and what a difference! It really settled the front end down and also reduced the wander.

Let me suggest that you get your RV weighed at one of the places that can give you individual wheel weights as that would help you to make sure that you have the proper balancing of the load. That can make a major difference in handling, both front to back and also side to side.

 

[BrunoMTP]

So...went for a short trip of about 100 miles with the Koni's installed on the rear. They definitely helped by turning the rear end slam into more of bump, but truth to tell I miss the air shock ride of the old 82' E350 Jamboree.

Still haven't found any place local to do the individual wheel weighting. Am basically done at this point with the suspension upgrades except for the Caster fix.