Ye ole steering wander problem...

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

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.

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.

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.

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".

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

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