Ye ole steering wander problem...

[goufgators]

This question/comments is in regard to a 2017 Thor Freedom Elite 29FE. The problem is the old story of steering wander. I’ve had the wheels balanced and the front end aligned. I tried to get the alignment guy to set the alignment at 5 degrees toe in as I’ve heard that is good to help with the wandering problem. He refused to agree to that request. I’ve got the tires aired to comply with weight. So, after doing all the above, the wandering problem still exists. Question for those of you who have put add-ons such as steer safe or trac bars, what did you add that made an appreciable difference? I’d like to know your opinions re: add-ons before I venture down that road. (I’ll also add this post to the Class C forum)

[Harvard]

Yes, I agree with John, with more the 2 degrees the bushing walls would be thinner.

[j-d]

Harvard, Reading all this and thinking about it, this is my summary:

Ford builds the frame and the axle to provide about 3.0* Caster Left and 3.5* Caster Right (Cross Caster 0.5* for Crown of Road). "Zero Offset" bushings would leave Caster at 3.0 and 3.5.

Ford adds offset bushings to reach the numbers you provided, adding a degree or so. Maybe only on Cutaways destined to be Box Trucks or RV's

By installing Ingalls Bushings, we can approach 5.0 and 5.5.

Tempts me to consider offset bushings that offer more than +2.0, but Henderson didn't favor that. John liked two brands: Ingalls and Specialty, and both are 2.0

A

[Harvard]

Hi JD: To this day I have no idea what my actual caster or camber are running at because I have never gone back to an alignment shop. All I have is a print out from the alignment in Calgary on 15OCT2010. We then made the trip south during which I realized the alignment did nothing to help with handling. Then on 16NOV2010 in the Coach Stop RV Park, Wellton AZ, I did the dirty deed of adding 2 degrees caster. I know the date because of my fuel records, I drove to Tacna (10 miles and fuelled up) to see if the wheels were going to fall off. I admit at the time I was scared, not having any experience with anything to do with caster.

At the time on RV Net, every one was saying "get an alignment" but nobody was posting any before and after alignment reports so we could see what was changed when the handling issues were resolved. At the time I was calling their experiences "miracle alignments".

[j-d]

Good to hear from you, Harvard!
Do you think your recommendation applies even when the OEM Axle already has Offset (but not Adjustable) Bushings of unknown values?
Is your 0.125 in Inches? and where are you measuring it? When I do DIY Toe, I put hat pins into the tread edges at the Rear of both front tires, as high as I can and still get a tape measure straight across to measure the distance. Then, using your number, I'd roll the coach ahead till I could measure the distance across the front of the treads, adjusting Tie Rod Ends to get Front Distance 0.125" closer than the Rear Distance. So the 0.125" would be set pretty close to the diameter of a tire. For you, the Axle in question is the 2012 Quigley take-off in installed in our 2002 chassis and sent you some angles on. You thought the Caster was already close to 4* + something.

For those watching at home, Harvard may not call himself Engineer, but he's very persistent, great mathematician, tireless researcher. Developed all this on his own, finding a solution most shops don't understand and are afraid to try. Henderson's being an exception. They'd been doing it right along. We just hadn't found out.

[Harvard]

Hi JD.

For the record, get a set of Ingalls 594s and "RubixCube" them to be +2.0 Degrees Caster and 0.0 Degrees Camber. Pull one wheel at a time and install them. Then set the toe to be 0.125 Toe In and you are good to go. That's what I did in an RV parking lot in Wellton AZ without the benefit of the hind sight I have now, 7 years later... I am not an engineer but I will bet my money on the engineering specifications that put all this hardware together in the first place.

[j-d]

Harvard wrote:
...when the Ingalls 594s were set to 0.0 degrees caster the alignment rack print out told me I had LH +3.3 and RH +3.5 degrees of caster.
My Caster Story Circa 2011

Those of you who haven't, the linked thread is a great read. I've been following this from almost before it started, and didn't realize till now that Harvard found the Ingalls bushings at Zero. I knew he wasn't satisfied with the alignment he'd had done. Also not sure I remembered he had an alignment report he took as accurate. I thought he decided to try more caster, then looked at the settings on the Ingalls bushings, found out from the Instruction Sheet said the degrees would be, and changed adjustment to add max caster which turned out to be 2*.

Point is, Harvard had the needed information, from the Alignment Report, AND the means to add Caster since the Ingalls bushings were already there. But if one of us doesn't have a Report, or a Bushing of known value, we don't have enough info and we don't have a way to add Caster without either (1) help from an alignment rack or (2) backing into a starting position for the Ingalls bushings that matches the fixed bushings, THEN adjusting the Ingalls to another 2* of Caster. Quite a challenge, and I haven't figured out how to meet it.

[Harvard]

Sam Spade wrote:

Harvard wrote:
A lot has been said about 5 degrees of caster for the E Series and in hind sight it should been said to just add +2 degrees of caster with the bushings.

No, I don't think that is right at all.
Or at least grossly misleading.

What if you started out at 0. Then you would end up at +2 which is still not nearly enough.

Sorry Sam, I left a lot of detail out of my post.

It is my belief that Ford ships these cutaways with +3.5 to +4.5 degrees of runtime caster depending on the for aft nose attitude. Again, it is my belief that Ford installs the "keyed" bushing so that they can simply "adjust the toe and its good to go" alignment on the assembly line.

So by adding +2 degrees with Ingalls 594 bushings the unit will end up with +5.5 to +6.5 degrees of runtime caster. So, my suggestion is not to be specific of +5.0 degrees BUT to take all you can get from the Ingalls 594 bushings. One other point, from my hands on experience with our E450, which travels one degree nose down, when the Ingalls 594s were set to 0.0 degrees caster the alignment rack print out told me I had LH +3.3 and RH +3.5 degrees of caster.

My Caster Story Circa 2011

[fortytwo]

If the tail (overhand behind the rear wheels) is too long, it will NEVER be a hands off coach. All of the things suggested will contribute to "some" improvement (track bars and steer stabilizers more than others) and go from white knuckle to manageable. If your wheelbase to overall length is over 55% you have a poorly designed coach - something that has been known for over two decades. Manufacturers don't care. The Marketing department rules; engineers suck wind.

[Sam_Spade]

Harvard wrote:
A lot has been said about 5 degrees of caster for the E Series and in hind sight it should been said to just add +2 degrees of caster with the bushings.

No, I don't think that is right at all.
Or at least grossly misleading.

What if you started out at 0. Then you would end up at +2 which is still not nearly enough.

[Sam_Spade]

ron.dittmer wrote:

- front wheel alignment which required offset bushings.

The difference went from a drunken sailor to a stead-as-she-goes experience.

First place I went to told me that the front end was "worn out" and needed $3000 in repairs before they could do an alignment using the procedure that I printed out from a post on here.

I walked. It wasn't old enough to be "worn out".

The second place looked at the sheet I gave them and said "Sure. We've done that before a few times." About $300 later and it was rock solid; well, as solid as a big "box truck" can be if the wind is blowing.

Which is why I suggest doing the alignment part FIRST to see what the result will be.

Doing ALL OF THAT EXPENSIVE STUFF at the same time won't allow you to know which parts were really necessary and which not.

But......it's your time and your money and you need to do whatever YOU think is right......for you. That doesn't mean that it is right for everybody though.

[Harvard]

A lot has been said about 5 degrees of caster for the E Series and in hind sight it should been said to just add +2 degrees of caster with the bushings.

As such, in my case, I would be riding with +6 degrees IF my fore to aft profile were level. But I am not level, I travel at about 1.0 degree nose down so my runtime (or alignment rack) caster is about +5 degrees AFTER adding the +2.

[ron_dittmer]

j-d has it right.

But if you are like me, degrees of caster and all that tech-talk becomes over-whelming. So here is my plain and simple story about our rig "Wandering" all over the road.

When we bought our 2007 E350 chassis motor home brand new, it handled like a drunken sailor. A few months later, I took the rig fully loaded as if ready to leave home for a trip, to our local truck suspension shop HERE. George at Champion Frame Align recommended the following which I agreed to having Champion do.

- rear heavy duty Roadmaster stabilizer bar
- front heavy duty Roadmaster stabilizer bar
- front Safe-T-Plus steering stabilizer
- heavy duty Koni-RV adjustable shock absorbers set to the strongest setting
- rear Henderson trac bar
- front wheel alignment which required offset bushings.

The difference went from a drunken sailor to a stead-as-she-goes experience. I went from two hands clinging to the steering wheel compensating constantly, to one hand gently holding it steady. Driving it for the past 10 years since the work was done, has been a real pleasure. My wife and I both enjoy driving, even with trucks passing, reasonably uneven road surfaces, and the occasional side blast of wind.

If I had it to do over again back in 2007, I would have gone with the heavy duty Bilstein shocks because I still get a little front end up/down porpoising action because our rig is light up front and heavy behind the rear axle. Today because they are now available, I would consider the Koni-FSD-RV shocks.

[j-d]

I read the first post, to think OP has weighed this coach, at least by axle (not corner maybe) since he says he's set Tires to Weight. So I asked what those weights actually were. "More is Good" doesn't apply to Front Tire pressure on a Ford Class C.

My take on Henderson's "S-T-P like going to 5* Caster" is that it's based on a unit with the front end in good condition AND aligned to spec. That said, the Mid Range of the Spec is 3*. Our good friend Harvard came up with the 5* number having found he had Ingalls Adjustable Bushings. Somebody had supposedly done an alignment and probably set to 3* calling it "spec" since it's mid range. Sadly, many shops "align" Ford Twin-I-Beam Axles "Toe and Go" doing only the Toe and ignore Caster and Camber.

So, adding an S-T-P (or an RSS-C) could help apply centering force like more Caster will.

Please note that many application catalogs/web pages do NOT show Adjustable Bushings for RV Chassis and Box Trucks, basically anything with Dual Rear Wheels. They believe that the Adjustable Bushings will not stay in place. Non-adjustable (Fixed) bushings have a Key on them, that engages the Pinch Bolt that holds the Ball Joint in place. Adjustables can't have those, because they have to be turned to various positions to achieve adjustment. Again Henderson... Says They Will Stay if Installed Clean and Properly Torqued. The Pinch bolt isn't all that big but its torque spec is something like 65-ft-lb. I've had alignment shops tell me if they find Adjustables they take them out and use Fixed Bushings.

[ncscz]

I did not see anywhere in the thread where you weighed the coach. If you have not done a 4 corner weight (loaded for travel), you should do that FIRST !!!