Any problems by increasing caster to 4-5 degrees?

[S.LANGE]

Have any of the E350/450 owners, who have actually achieved the "increased to 4 degree to 6 degree caster", had subsequent challenges to other front end components (ball joints, tie rods, steering linkage, tires, etc.) where the increased caster was the initial root cause?

If you did achieve the increased caster utilizing adjustable bushings (aka MOOG #K8986/Ingall's #59400, or equivalent), that were installed properly and torqued to specifications, did they eventually loosen and or cause problems that wouldn't have occurred with one-setting only keyed bushings?

As you might guess I'm running into push-back and reluctance from every shop I talk to in trying to get the caster increased to the values that appear to make these vehicles (with their weights & measures and characteristics in traveling trim) to work favorably (within reason) and am trying to find out if there is any shred of evidence that the warnings and cautions are valid.

I've upgraded/added several items, each improving the drive-ability/ride and have yet to install the Trac-Bar and the Safe-T-Plus. I don't want the Safe-T-Plus to be doing the "work" of keeping the MH going straight under 'normal, no outside influence conditions'. I want it only come into play when an anomaly calls for it, otherwise just idling along for the ride.

I'm assuming the increased caster without detrimental effects can be done but maybe I'm asking for too much.

All I know is, over the last few years, the much in-person verbal advice from various Rv and truck service centers is pure bull. "Load 'er up with more weight over the rear axle to make it ride smoother" -- really(?) its already max'd out and that doesn't seem safe, "RV shocks are no better than OEM from Ford & they all come from Chinese mgr, just painted different color", "your rig already has sway bars", "SUMOSPRINGS is just a gimmick", etc.

I have found a couple of good businesses here in Phoenix, AZ for what they do. E450 alignment issues - not so far.

[sibe]

find an old time real alignment guy...

very few new techs have a clue on theory and why, only what the alignment machine training tells them..

I have had vans and some RVs, I had/have a Frame shop.. dont do alignments myself anymore unless it is on my E350.. LOL. I borrow a machine at local truck shop..

I have no ill affects on the 1994 E350 with 196k pluss on it.. I did Ball joints at 138K, towed a 6k pluss trailer...many weekends..
It wore tires ok good, Running no trailer i would do fine, trailers would accelerate wear alot , braking , pushing etc..

My new to me 96 e350 29RQ winnie, Maxed on weight , tow rarely..
Camber runs a bit positive .5 degree or so spec is 0-1

Caster Left 4.75 Right 5.1 ish.. I used adjust top sleeves ac delco brand, same as napa, moog etc.. Left side i got close with a spinning a factory2.0 cam but the rt side was a bugger..
I changed radius bushing even with 30k orig miles. one on rt was ovaled,, typical ford..

anyway.. it took me all day ,, and then once done, i reset machine after a test ride and it held within 3/8 of degree all around..


If I had to charge for the job with parts 650 min.. should have added poly sway busing while i had apart..

The factory upper cams came out easy, so not beating of ball joint occured..
many time stubborn upper cams/adjusters will casue stress to uper or lower ball joints, from haesh beating apart but some techs,, they fail soon after and BLAME those settings you wanted

[youracman]

Mine were installed about 4 years ago. No problems of any kind thus far.

PO had installed Helwigs, Bilsteins and a Steer Safe. Rig drove pretty well, I thought. [IMHO, my 220" wheelbase helps ....... but it takes 2 acres to turn it around. :^(( ] With the added castor via the special bushings it definitely drives better. I asked my local Ford Medium Duty Truck dealer in advance if I could bring my own bushings and have them install them as part of my alignment...and they agreed (kinda surprised me.) I ended up with +5 on the right and +4-3/4 on the left. IIRC the job was about $275 out the door and the tech went over his findings with me when he finished (that kinda surprised me too.) He said the lower amt on the left was for what he called "lead" ...... I believe this is for the crown in the road? I do a lot of my own work, but front end work is WAY above my pay grade.

Just my 'sperience: It seems like your nearest Ford Medium Duty truck dealer may the place to go. A LOT of RVers here in Denver use them for chassis stuff. Finding independents to do the work is not easy...... I tried. I really think a lot of them are too busy picking the "low hanging fruit" and are not interested in anything else ......... that'll change one day I believe.

Good luck on the mod.......... and safe travels to ya.

[Ron Dittmer]

Hi S.LANGE,

You may find my experience with a recent E350 front wheel alignment very interesting. CLICK HERE and scroll down to the end of the opening post in the "SUPPLIMENT MAY 2021" section. The last picture was taken from my 2007 E350 Ford shop manual where it states the camber and caster nominal setting and tolerance. The question you ask is irrelevant because your request is within the spec.

I had thought a fully adjustable 2-piece alignment bushing would have been ideal to zero in on a perfect alignment, but the alignment shop I used refused to use them. They said the wheel alignment always drifts off using an offset bushing-within-an-offset-bushing design because of the dynamics and stresses when being driven. The clamping retaining bolt cannot keep it from moving around. So don't go there if you are later tempted.

[S.LANGE]

Hi Ron,
Thanks for your response and posting the link to your personal experience and beautiful sharp and crisp photos in the gallery. The visuals certainly help. To be honest, I saw it a few days ago as I've learned over the last few years to look to your posts due to their clarity and insightful content. You certainly are an asset to all the forums you avail yourself to.
The caster, camber, and toe specs on the page from your 2007 Workshop Manual are exactly the same as values on same page (ref 204-00-1) of my 2006 manual.

From what I can tell, referring to the caster values:

(L) 4.1 degrees +/- 2.75 degrees
(R) 4.5 degrees +/- 2.75 degrees produces a pretty liberal range and as I and others have found (I'm assuming), many shops achieve readings within those loose ranges and indicate "it's within Ford specs, nothing more we can do, you should be good to go".

That's what I got from my last visit and the printout says I'm at (L) 2.7 / (R) 2.5. Lately i've been told that my (L)>(R) value is adding to the drift to the right my MH has.

And I can't comprehend how I'd achieve 5 or 5.5 with a 2 degree adjustable bushing so that's probably a no-brainer (for which I'm well suited).

I'm trying to overcome my naivety on the subject and actually work towards making the steering safe and stable.
So sorry to hear your long time relationship with Champion came to an end. I was disheartened to read that the other day as I'm sure their collective knowledge and experience will be missed. But it sounds like you have a sound replacement.

I have an experienced mechanic friend and he's helping with some general theory/knowledge and the trade-offs of one setting versus another but his expertise is not Ford E-450 chassised motorhomes. Though Porsche 911's are rear weight biased vehicles.

[Ron Dittmer]

Thank You S.LANGE for the encouragement. It's nice to know that a few people actually "read" my posts rather than scan through them.

All my acquired knowledge regarding a Ford E350/E450 wheel alignment is from that single wheel alignment experience with my 2007 E350 based motorhome. The guys at the alignment shop were very kind. They were fine with me watching for the sake of knowledge. I did ask them up front and I was respectful to keep out of their way and also kept my questions to a minimum. The technician doing the alignment was so kind that when he saw me sitting on the concrete floor, leaning against the overhead door frame, he left and came back with a shop stool for me to sit on.

My main point here is....I'm no good when it gets too technical. But I was very observant watching their computer screen, watching "cause and effect". Adjusting it better on one scale, made it worse on another scale. Another challenge was when tightening things up. The numbers would change, so they had to anticipate "settling" when tightening an adjustment. It was surely a delicate balancing act.

One thing I concluded from my observations is that asking for more caster will yield worse camber. My advise is to let them do their best and accept the results as long as the over-all results are within spec. I don't know how to ask for more caster without the front tires being pigeon-toed inward or angled outward. You might be able to get the best of both worlds by changing the off-set bushings with different ones, but that gets real deep. A $150 wheel alignment could cost nearly $1000 and you could still have unsatisfactory results.

[DonaC]

Originally Posted by Ron Dittmer

One thing I concluded from my observations is that asking for more caster will yield worse camber. My advise is to let them do their best and accept the results as long as the over-all results are within spec.

Yes, this, exactly. Once the tech has installed the adjustable bushings he can adjust the upper bushing in a circle, 360 degrees. But If he already knows the camber that he needs, there are only two places in that circle of adjustment that he has available that will set that correct camber. One of his two possible adjustments has more caster than the other, so that's the spot he will select. It's not a lot of choice. If the caster is still not enough, he has to take the front end apart again to put in a different set of adjustable bushings, and most of these people are busy, with another customer waiting, and he won't want to do that. If only one side needs a small adjustment will he order two more adjustable bushings and then end up with two extra new ones to throw away, with the customer unhappily paying for both, and delaying completion of the whole job? All of the bushings in the suspension that attach to the chassis are rubber and have some give so he knows that no adjustment that he makes is exact anyway. He'll do his best and if he's given you a little more caster than you had before, while staying in the book tolerance, he'll call it good and send you on your way. If the customer insists that more caster is needed, because he's been reading about this on these forums, there's going to be a temptation to mis-adjust the camber to get more caster, and we really don't want that.

[MW22r]

I'm not sure. I have been relatively happy with my E-350 chassis but always keeping my eyes open for improvements. I just attended a FMCA Great Lakes area rally and a national company that specializes in steering and handling products was present. Talked to the owner. Didnt think I needed to increase caster as I have the safe t plus steering stabilizer on the front end but did recommend a trac bar for the rear end. Other than perhaps upgraded shocks he thought any other attempts to improve handling was just spending money unneccesarily without the likelihood of making noticeable changes for such a small and light chassis. Weight distribution( light front end) and tire air pressure are a given.....just sharing my thougts.....bob

[VanDiemen23]

On a double A-arm suspension you have to re-set camber after caster and then toe after camber. Caster is the angle of a line through the upper and lower ball joints in the fore-aft plane compared to a vertical line.

The more caster, the more the vehicle self-centers. When you turn the steering wheel, it actually pushes the inside tire down (effectively lifting the vehicle using the steering wheel as a lever). This puts more stress on all the elements of the steering system. Its the system trying to equalize the forces (weights and the angles involved) that causes the self-centering. The Saf-T-plus does this with springs.

On heavily loaded vehicles and ones without power steering, reducing caster results in much less steering effort, but more small steering inputs. It also makes the car quicker to change direction (less stable)

In the car in my avatar, which generates a reasonable amount of downforce, in certain high-speed corners once the car took a set I could not turn the wheel without incredible amounts of force (no power steering and a 10-inch steering wheel). This made me less precise in placing the car and also wore me out. I took caster out and it was much easier to drive fast - except on long high speed straights, which required constant correction over every bump and seam, scaring the crap out of me in several places. I later found out this was mostly because there was too much difference in caster right/left. Not really relevant to this discussion, but that resulted in a complete tear down of the car, marking lines on the floor and devising means to make measurements of locations, putting all of that in CAD and simulating the movement and everything was fine. The I jigged all the suspension pieces to be equal within .002", put the items on the car and did the alignment measurements and STILL found it to asymmetric. Built another jig and determined that the problem was manufacturing tolerances in the a-arms. in other words, it doesn't take much to throw off the whole shitteree.

The point of that is that yes, on road cars there's often some "lead" either designed in or adjusted in, but you want that to be the minimum required so that it doesn't create stability issues. IIRC the difference rt/left on my car in caster was .75 deg.

You can adjust caster by moving the inside attachment points of the a-arms fore/aft with respect to each other, or by changing the position of the upper and lower attachment of the a-arms to the hub with offset bushings. Since there are limited adjustment options for the inside attachments on road car designs, and those adjustment are primarily for camber, I suppose that leaves you with offset bushings to get the rest of it.

One way to keep those concentric bushings from moving after getting the setting you want would be to tack weld them together. This might be expensive given that you'd want to do a road test to see if the setting is what you want, and then disassemble it enough to get rubber bits out of the way for the weld, although if you TIG it, a wet rag wrapped around the boot would probably work fine.

For the future then, you would have to deal with wear issues by replacing other parts, as you know the kingpin is where you want it.

One way to do it might be to get the caster as far as it will go with the stock setup, adjust camber and toe to the proper spec, and then see where the caster ends up. Then, with a little math, you know what the offset bushings need to be machined to to add more caster, and you could have solid, non-adjustable ones made.

And tightening the jam nuts does change things. The real solution to that is just loosening the jam nut enough to move the adjuster and always work against some friction, but that's slow and tedious (although, not as slow and tedious as trying to estimate where the measurement will be when tightened, or going back and forth trying to hone in on the number you want). The measurements change because the jam nut is shortening or lengthening the arm as it takes out the slop required for the threads to move.

You can do a lot of this at a reasonable price at home. You need a good caster/camber gauge like this one:
https://www.longacreracing.com/produ...uge-NO-ADAPTER

Use the big ford adapter if you can get to the spindle because the magnetic ones require a true surface to work off of. Another way is to use the triangular ones that reference to the rims and a bungee to hold it in place.

You take four sheets of aluminum or steel about 1' square and make slip plates by putting a layer of grease between them. You jack up the vehicle and put the slip plates underneath each tire. This allows the adjustments to skid the tire without binding forces.

Now you can adjust caster and camber to your hearts content, figure things out, and then just take it to an alignment shop for final numbers and setting toe (you can actually do toe too, but that's kind of fiddly for the shade tree mechanic). Then you sell the gauge on ebay. This will cost you a lot less than having shops go through the iterations on their machine while you try to figure out what works.

[DonaC]

Good information, but I don't think that all of those adjustments that you mention are available on the Econoline's simple twin I-beam chassis.

[VanDiemen23]

They still use that POS twin I? I figured they'd gone to upper/lower control arms by now.

From what I can see an excentric on the inner pivot controls camber pretty independently.

caster looks like it can be changed a number of ways - raising or lowering the pivot at the rear of the trailing arm (probably the easiest way) , or offset bushings at the kingpin. the inside bushing has to be able to accommodate the change in caster, because you'll be twisting it.

The problem with the twin I beam design is that it has no camber control - the tire just describes an arc throughout the entire motion of the suspension, with it going highly positive in droop to highly negative in bump. it's also going to scrub the tire laterally with any suspension movement.

[twinboat]

Originally Posted by VanDiemen23

They still use that POS twin I? I figured they'd gone to upper/lower control arms by now.



From what I can see an excentric on the inner pivot controls camber pretty independently.



caster looks like it can be changed a number of ways - raising or lowering the pivot at the rear of the trailing arm (probably the easiest way) , or offset bushings at the kingpin. the inside bushing has to be able to accommodate the change in caster, because you'll be twisting it.



The problem with the twin I beam design is that it has no camber control - the tire just describes an arc throughout the entire motion of the suspension, with it going highly positive in droop to highly negative in bump. it's also going to scrub the tire laterally with any suspension movement.

No King pins anymore. Ball joints now.

The upper ball joint sits in a large eccentric bushing that can be rotated in its bore to adjust caster and camber.

[S.LANGE]

A big thank you to all respondents, and I hope there may be more. Very helpful input for me and I hope to others that stumble onto this and the other threads (historical and more current) who are addressing their "E's" steering issues.

As has been pointed out several times in other posts, Ford's intention may not have not have been for several of these chassis' to be used as leisure vehicles with every capacity max'd out as they have become, driven at highway speeds over long distances and hours.
Still haven't heard a horror story on the adjustable bushings nor the increased degree ranging caster directly causing issues, but we may. I've read several references involving "Harvard" and the successes he had and appreciate all he's contributed. He and others have indicated the solution for each particular MH can be elusive.
I'm frustrated but won't give up. Rear TRAC BAR installation first as recommended above and already in service on some of your coaches. My mechanic friend indicated I should eliminate as much dynamic rear end influence on the front as possible, among other traveling suggestions. Told me I should request as much caster as they can muster within reason taking into account the camber and possibly a bit more toe than normal. And be sure to let them know the tires will age out long before I'll cover enough miles to wear them out.
And I may have to set aside my prejudices concerning the Safe-T-Plus/Roadmaster Reflex Steering Stabilizer products actually doing what should already be present. Maybe it can't be within my circumstances.

[DonaC]

I really wish that Ford or some aftermarket source had developed more ways to adjust this suspension, but other than the adjustable upper ball joint bushing, it doesn't seem to exist. I've searched a lot. The chassis ends of the I-beams and the radius arms are fixed and use concentric bushings, they don't adjust. Making sure the bushings are in good condition is all you can do.

One thing does exist that looks very interesting is the kits from Weldtec designs. They have special radius arms and I-beams that are used to raise the whole front end. They claim much improved handling and ride and it appears to be true. But they raise the whole RV by at least three inches and I don't want that. And the kits aren't cheap.

Originally Posted by VanDiemen23

They still use that POS twin I? I figured they'd gone to upper/lower control arms by now.

From what I can see an excentric on the inner pivot controls camber pretty independently.

caster looks like it can be changed a number of ways - raising or lowering the pivot at the rear of the trailing arm (probably the easiest way) , or offset bushings at the kingpin. the inside bushing has to be able to accommodate the change in caster, because you'll be twisting it.

The problem with the twin I beam design is that it has no camber control - the tire just describes an arc throughout the entire motion of the suspension, with it going highly positive in droop to highly negative in bump. it's also going to scrub the tire laterally with any suspension movement.