too much caster ??? UPDATE-FIXED !

what are the symptoms of having too much caster, other than "jacking up" the front wheels turning lock-to-lock while standing still ?
handling symptoms ? road feel ?
can reasonable camber cause issues with too much caster ?
also, how much cross caster is allowable in "normal" circumstances ?
would an X frame chassis flex too much using excessive caster ?
yes, i'm still chasing some issues on a brand "C" for those that remember other questions i have posted in the past.
TIA as always for the wisdom of those way smarter than me, and the opinions thereof.

What is the car set at now?

caster : left-5.90, right-5.46
camber : left : -1.71, right: -1.24
toe : -1/8"

I wonder if "too much" exists, or if one could ever achieve "too much". It seems to me, most like more caster, and settle for whatever they get additional. Only downside at my pay grade I can think of, is the greater steering effort needed with greater caster, and the possible inclination to want "snap back" with extreme caster, if that is possible. It is a question I have never seen raised before.

this problem has existed after converting from manual to a 500 series power box using a GM "type 2" pump.
the assist is fine [way better than the "armstrong" box was] however, going down the road, it seems you always have to correct it.
at a minute correction, it seems the box wants to "keep correcting", then you input a minor correction the opposite way, and the box keeps correcting, rinse and repeat.
the pump is over driven now, [this setup is somewhat of a kit application. it came with the bracketry to fit the pump to the engine, but no pulley] but i can't find out what the original ratio was for the pump. it was a four cylinder pontiac application.
i got a flow valve restrictor to try, so we shall see how that goes.

Is that the 58 Chevrolet. If so I think there is to much positive caster and to much negative camber. Personally I think you should have 2.5 to 3.5 positive caster, .5 Positive Camber and set the toe a little more 3/16 to 1/4 inch.

my money is on the toe... go out.......

i'm beginning to think you are right about where this should be set to. and yes, this is the 58 impala.
the flow restrictor helped some, and i have advocated more toe in to my buddy for quite a while.
ek, having less toe in would make it worse, i think.

for those that don't recall, this car came with air bags and [factory] manual steering originally, and that bag setup was a hack install.
the car was not fun to drive, so the first thing done was to install the 500 power box. that was an improvement, but the bag system was constantly acting up. so the next thing done was to replace the front bags with the factory coil springs and new tube control arms, along with all the bushings, tierod ends, etc. the rear bags were also replaced with springs, and while the springs were out, the lower control arms were boxed and all the rear bushings were replaced.
when he took the car in to get aligned, i told him to try to get around 4 positive caster and around -3/4 camber, with 1/8" toe in.
the shop doing the work has been around for almost 70 years, and is considered to be the best in the area. why they ended up with so much negative camber, i can't answer.
also, having 14" tires doesn't help any, even if they are new. [in my opinion]
the problem was there before the tires were replaced, so i'm confident it isn't tire related.
i'll get this thing straightened out eventually, but in all the years i have been playing with cars, this thing is "driving" me nutz !

It would be interesting to see what the factory PS alignment setting recommendation was.
But I would think it should have more neg caster on the right, and equal camber.
FWIW, and it's a different steering setup, my Duster drag car (Jack Arnew-modified) runs about 7 deg caster and goes straight as a string.
But you wouldn't want to stick your hand between the steering wheel spokes when the steering unwinds...

Moparx, that is a lot of negative camber for a street car. If the tires are narrow, it might be workable, but narrow tires aren't my wheelhouse. On a road course, it would be almost overkill, but would have great "turn-in" until the tires likely wore out. I would dial that camber number back first and see what improvement it makes. No way your posted caster numbers are overkill IMO.

This should be factory specs. Caster-Zero, Camber +1/2 deg. Toe-In Inch 1/32-3/32

If you really want your friend to make this car better get it aligned to the specs I posted. Another thing is mis-matched incompatible parts such as pitman, idler and center link. If all is ok then get it aligned.

from what i have seen over the years, most "old" cars used positive camber because of the bias ply tires ?
i agree that the camber needs dialed back as well, maybe to a -3/4 or so.
and yes, i firmly believe the caster on this setup [now] is, or should be, good.
for the last couple of months, my knees and hips have been giving me tons of problems, so i haven't been crawling under this thing much.
i need to get under it again and just lay there looking, maybe seeing something i may have missed.
i do remember when the power box was installed, the crank pulley added to run the pump kissed the factory sway bay, so it was removed.
i have often wondered if spacing it slightly down and slightly forward to clear the pulley, and reinstalling it, would change anything.

so far this spring, there have been other projects coming and going before jumping back to this one.
a new front driveshaft section was built [the old shaft section ahead of the carrier bearing was too short and the joints were clocked off quite a bit] and a change to 3.08 gears from 3.36's were done first before getting back into the steering issue.
a couple of things i have discovered this year for sure. the older i get, the "dummer" i am, and fridays come lots "quicker" these days !

and yes, i'll get the car re-aligned. this time, i'll go with him so it's to your specs !

You need to do it. Right now you have way to much caster, way to much negative camber and the toe needs to be in not out. Once you hit those numbers you can then deal with other possibilities.If you can not align it to those specs I suspect there is an incapability in the parts and with geometry being off that is most likely the issue. If that car was to come to me that is what I would have it aligned to. If the customer wants to debate the reasoning he can go and argue with someone else. I could be rich if I could fix stupid.

Why too much caster for OP?
I believe the goalposts on caster settings have moved since 1958, when cars were often manually steered, and steering effort was a concern.

Excessive caster may be a possibility. You have 2 numbers that dictate steering centering, kingpin angle and caster. One or the other is going to be what determines centering, generally they are far enough apart that it's clear which one is the dominant factor.

You might have them close enough that the physics is confused and it's not clear which one is doing the centering.

My understanding though is that when this happens, you get a shimmy or death wobble.

Do your alignment printouts list kingpin angle? Note it might be called SAI. Or if included angle is listed we can calculate it.

Edit, have you tried driving it with the belt off the pump?

Kingpin angle is not normally an adjustable setting as i understand it. If that is the case, why does matter if its at its OEM number?
I also am uncertain how it plays much of a part by itself in "centering".
care to explain?

kingpin/steering axis inclination is the imaginary line formed by the tilt inward of the upper ball joint [or kingpin] from true vertical compared to the spindle's horizontal line. this is controlled by the way the spindle is made, so it is a segment that can't be changed.
it's purpose is to place the vehicle load on the road contact patch of the tire, providing better tracking and easier steering.
this only works for OEM applications, using the parts designed for the vehicle in question.
any mix and match of control arms, spindles, and wheel offsets throws this spec out the window.
a guy can math out the original setup then do the same after the parts used to see how far off or close you come to OEM, but it is hardly, if ever, done.

Correct, kingpin is a manufactured number not adjustable. It does affect centering, think of a crooked gate hinge, the gate will stay at the low point. It's just opposite in a car as the weight of the vehicle is pushing down.

Most SLA cars rely on caster for centering , strut front ends tend to favor kingpin angle. One or the other is needed for centering, if they are too close stability can be compromised.

I guess one way to think of kingpin angle is caster rotated 90 degrees. Not front to back but side to side.

I think the problem may be with those tubular control arms.

You could plot the caster, camber and toe change through the suspension's range of motion or replace them with a set of stock ones and see if the problem goes away.

There's not a lot of things to cause this. A balljoint with a tight spot in it or the box itself but you seem to have covered those bases.

You could take it to another alignment shop, don't tell them anything other than you want them to set it up on the machine to check it and see if their results resemble the readout from the shop you are using.

Kevin

Speaking of tight spots, did the drag link ever get checked?

It would help if we could combine the 3 or 4 threads about this

the draglink has been rebuilt, and has no play whatsoever.
in fact, every moving part has been checked multiple times, and there is no play anywhere in anything that pivots or moves up and down.
it's getting to the point where i think there may be so many aftermarket parts plus a mix of items that just "fit", that the basic geometry is plain screwed up.
someone suggested plotting the suspension curve, and i think that is a prudent move.
however, since the weather is nice, he is constantly on the go, and i don't know if i can get him to sit still long enough to pop the front springs out to really get an idea what is going on with the suspension moving through it's whole range of travel.
i am not literate enough to do a computer analysis of this. i need to see it in real time, then use measurements and some math to figure it somewhat close.
one thing i haven't done though, because it would take me some time doing.
i have all the "old time" home alignment tools. magnetic spindle mount caster/camber gauge, swivel turn plates, and toe stick. it would be interesting to see what i would get if i spent a day or two checking with my tools.

Just get it on the rack and align it. The way it is now is not right. In a few minutes after the caster swings are made you will see exactly what it is. Steering angle, thrust angle along with all the readings for caster, camber, toe. If it aligns to the specs I gave you then deal with any problems. If your friend is that busy he must not care about the issue. Neither should you if thats the case.

here is a pic of the last alignment done in august of last year.
i remember now it was mentioned the way the upper arms were mounted, [inboard of the chassis mounting point] all the shims were removed, and the camber could not be made any more positive.
this is not a constant "sawing back and forth" [unsafe] correction needed, rather just a minute thing that gets bothersome/tiring after a 3 hour drive.
of all the power steering conversions he and i have made over a 50 year friendship, this is the first one that has had this symptom/problem.
the vendor that supplied the box said this box is designed to be tight on center instead of having the minute play other boxes have.
tossing $100 bills to the alignment place every time isn't much fun, especially since i have the tools and know how to use them, although it is getting difficult to crawl around like i used to.

The way that print out is it looks like they did not adjust anything. One other thing I did not like is the included angle is less than the SAI angle and the included angle should be more. Again that car is not in line. If a proper alignment was done those numbers could be then in specs. Tell your pal to quit screwing around and get it to a qualified alignment shop.

The math checks out for the difference between sai and included angle, remember there's a ton of negative camber.

But included angle is close to caster which may be affecting directional stability.

Do you have the original control arms?

Also, back off the adjuster on the drag link, too tight can bind the steering. Its spring loaded and should have some (minimal) play.

I don't know bleep about 58 c-cars.
With the aftermarket upper tubular control arms currently made for Mopar, I think most can be swapped left for right.
If this is possible on this car, try swapping them.
The OEM B body upper arms, '62-'72 , actually have the upper ball joint offset slightly forward to REDUCE caster angle!
And as others have said, return everything to stock, and start over.

It's actually a 58 Impala. But good point about having the arms on the wrong side.

My '69 Darts, manual steering, max caster with stock suspension, the wheel would snap back very fast when turning fast in parking lots. Not so with my power steering car that have more caster than is achievable with stock suspension.

to be continued...............

based on what i see/read.... your cross member is sagging. this was very common on those cars. you most likely cant get enough adjustment to correct your camber. moog used to make a [ 2*] shaft /bushing kit to correct this. .usually all the shims are out and you have no more room for adjustments ! to fix it , you chain it down on a frame machine and pick the center up to get it back to specs. your toe should be good at 1/8" in and your camber should be positive on both sides not negative.to start get it around .5 pos right and 1.0 pos left . this is for radial tires....the camber split keeps it true on the slanted road.. caster is not the issue... check it and let me know . i am 99% sure this is whats going on.... Does the power steering box have the directional assist valve on the bottom? thats the only other thing i can think of that would do this...

Positive camber????

WOW,

yes . positive camber... to the op. check the things i asked about and let me know where they are.... then i will re-think what i have posted... i dont think i am wrong and this will clear it up quickly. nobodys perfect ! i stand by my words... this is a rear steering car correct ???

Positive camber is fine for old school with narrow bias tires non handling goals. Negative for everything else.

It's an unusual problem but I've dealt with the same thing on 2nd generation Explorers. Excessive negative camber from the frame rails twisting inward. My only concern with such a diagnosis in this case is the aftermarket control arms and the possibility that they are not correct for the application.

this is a front steer car.
a trip to the frame machine was mentioned quite a while ago. i think the age, plus the botched air bag mess, has the crossmember ginked up.
went looking for the original control arms a couple of days ago to check their lengths against the tube arms, but i believe they may have been scrapped.

Just align it and see where it takes you. No sense overthinking this.

But, he can't get more camber. Getting less caster should be doable but camber will go more negative.

Have the knuckles changed too? Or just the arms?

<------------- ??? 1/2 deg. Positive camber ??

Yes

Most older rwd cars did indeed call for positive camber.

FINALLY, i have the answer.
believe it or not, the box itself was the problem.
a new box from summit, a 500 series CCP box [same as the old one] was installed over the weekend.
the car goes down the road and steers as it should have with the old box.
the pump, lines, and remote reservoir were cleaned and flushed, but prior to that, a magnet was inserted into them to see if there were any metallic particles floating around.
previously, before getting the box from summit, i was on hold for over THREE hours, trying to talk to a tech at CCP in california.
when i finally got to talk, [after listening for all that time about their "lifetime" guarantee] the tech suggested it could possibly be the box itself. BUT, in order to honor the warrantee , i would have to ship the box back, have them either repair or replace it, then have it shipped back. he had no timeline on how long it would take, although he kind of alluded it probably would be 6-10 weeks.
after figuring it would be roughly $200.00 in shipping costs, plus the time being down, we decided to get the same box from summit for $379.00
took three days to get, an hour to install [we had everything cleaned, flushed and ready], and down the road we went.
everything is good now, and all is well !
now to tear apart the old box to see if anything jumps out as to why this old box is so tight !
thanks all who offered suggestions and encouragement !

Wouldn’t Summit take it back? I thought their return policy was pretty good.

the first box was bought from CCP direct, not through summit. that's why the shipping back and forth to CCP.
if anything happens with this box, i'm sure there will be no problem returning it to summit.