My alignment guy doesn't know best

[hotrodneb]

OK....so I find a shop that says they will "align to my specs" AND let me be the alignment guy's new best friend for 45m. I walk in with my specs in hand. -.1 camber 5/4.5 caster and 1/8 toe. At the end he stated the toe and camber were to my specs BUT there was NO more caster available on the driver's side so I ended up with 3.8d Pass and 3.2d Driver's.

So I drive the car and it does alright in the city, but at highway speeds it tends to wander on center. I open the hood and "What to my wondering eyes did appear" but shims in the rear UCA studs. I pulled a 1/16 shim from the rear stud on both sides and went for a drive.

Surprise-Surprise, (Gomer Pile reference) The car drove wonderfully.

During the alignment I remember him saying something like "We do a lot of these and this is where they work usually anyway" (upon no more adjustment statement). I am certain HIS recommended specs work OK on a stock/modernized vehicle, but not mine.

Bottom line----stick to your guns and inspect everything.

[TheJDMan]

Better yet, learn to do your own wheel alignments! There are hundreds of DIY wheel alignment videos on youtube and there have been countless magazine articles written on the subject. A set of toe plates, a pair of matching tape measures, a digital level, some string and a little bit of knowledge is all you really need.

[hotrodneb]

Actually......I offered the shop owner $100 for a Hunter H-111 he had sitting there in the dust and he replied "That's the best offer I've had in years. My best friend is a master driveline tech and works at a dealership with the latest tech. I was just in a hurry and he has been backed up.

[sccacuda]

You trade camber for caster when your maxed on adjustment. If you removed a shim, the toe WILL be off.

[hotrodneb]

good point "sccacuda" I will go out and turn my adjusters out a couple flats each side until I can get it on the rack again. Mist likely I am at 0 or 1/8 out now.

[TheJDMan]

Buy yourself a set of toe plates, a digital level and some string. Or, you can continue to pay money for another shop alignment that isn't to your liking. Just sayin.

http://www.summitracing.com/parts/aa...0117/overview/

[hotrodneb]

Thank you for the advice, but--

I "have access" to a Hunter Hawkeye Elite. I just didn't want to wait until my buddy could fit it into his "after hours" time. I can't stop driving it and the beginning setup was really bad. The $50 I paid was cheap to me to save tires and drive safely until it can be alignedproperly. The original title here was going to be "My alignment guy sucks", but really he was doing what he thought best in his experience. He just didn't have experience with such a mod'd car.

[Kcrain]

Normal gm car removing shim from rear stud will decrease caster ( less high speed stability ) increase positive camber ( less high speed cornering) and throw off toe in. Sounds like you still need a real alignment.

[hotrodneb]

OK.....so I have these Ebay UCAs. They have off-center plugs that can be reversed to move the UCA forward/rearward. It is currently set up to move the UCA forward. Removing 1/16 rear shim helped high speed stabililty and return to center, telling me that I had increased caster.

I read up and you are correct that typically removing a rear shim decreases camber. This seems 180deg out of thinking. Removing a shim should move rear in, thereby rotating the outer part of the UCA and upper ball joint forward - increase caster. Any thoughts on my situation??

I thought I was smart, but now I seem as stupid as I've ever been.

[dontlifttoshift]

Stock subframe?

More shims on both studs = more negative camber

Less shims on both studs = less negative camber

More shims on the rear studs = more positive caster and more negative camber

Less shims on the rear studs = less positive caster and less negative camber

I'mm surprised you could tell a difference by removing a single 1/16" shim.

[dale68z]

Removing the rear shim decreased the caster on that side. Doing that created a slight pull to the other side. Making the car more predictable, stable.

If a car wanders I would first check if everything is tight. Then start thinking about caster, the more you have the more stable the car is and has more feed back to the driver. All good there... I'm looking at toe.

I really cannot imagine removing .060 of a shim in the rear will make any real change in toe. It will change it, but not enough to see it with a tape measure.

[hotrodneb]

I may have just realized the situation myself. The centerline of the spindle trails the lower ball joint, and the upper ball joint trails the centerline of the spindle. I was thinking a view from the driver's side looked like this "\" but the UCA trails the LCA like this "/"

SO---swapping my UCA to the reward position should yield as much caster as I can handle.

CORRECT????

[rustomatic]

I think the major point that you proved was that your random shim adjustment post-"alignment" created more positive change than what you paid the alignment guy for. Just a roll of string and a floor jack would have had you in better shape, even if it took you 12 tries (like me). People confuse the idea of "tech" with quality in alignments, and they have nothing to do with one another. It's all about removing the basic knowledge (includes visual detection ability) from the machine's operator . . .

What Donny and Steve said above will eventually save you a ton of time, money, and eventually frustration . . .

[TheJDMan]

I may have just realized the situation myself. The centerline of the spindle trails the lower ball joint, and the upper ball joint trails the centerline of the spindle. I was thinking a view from the driver's side looked like this "\" but the UCA trails the LCA like this "/"

SO---swapping my UCA to the reward position should yield as much caster as I can handle.

CORRECT????

That would be correct! I think you are on the right track now. Just keep in mind that changing caster will also change camber and toe. I understand you have a friend that does wheel alignments, but in the long run you will be doing yourself a huge favor if you learn how to do your own wheel alignments. Knowledge is never a bad thing!

[hotrodneb]

Ya....you might be selling me on an idea. Which says something since I am in sales myself.

Reinstalled both rear shims but replaced his 1/16 with a 1/8 on both sides. Now we're making progress. (improved test drive)

Moving UCAs to rear location next time I feel like getting a little dirty.

[Kcrain]

Forget what I said

[MonzaRacer]

A lot of cars built in this time frame of when your and my car were built were assembled with negitive caster. They had stability but handling sucked. Set the spacers in your control arm shafts to move to the rear for the final alignment to be done. When you go for alignment trust do you plan to drive mostly on the street you want drivers front 3/4 negitive camber 5-5.5 positive caster. Pas singer side 1 negitive camber and 5-5.5 positive caster and 1/8 toe in. The reason for the difference in camber is for the crown of the road. Same camber can cause a pull to the right on a crowned road. All roads are crowned for water runoff. Keith

WRONG!!!
As a 30+ yr alignment tech I rarely let a car go out with split camber. Reason: on left lane your car will then be driving left rather than wanting to "drift" left.
Camber in tire wear adjustment meant to keep tire as evenly applied to road as possible.
CASTER: on the other hand in a non tire wearing adjustment. Splitting caster can alleviate crown drift when driving on crowned roads(which is done to facilitate water runoff to ditches)so by adding from .25-.50 deg more positive caster to right side allows for it.
So all I hear is "I WANT OR HERE IS MY SPECS" and NONE of you actually explain what you want and why and ask for "X".
Now, most great, experienced alignment guys will listen, and attempt to achieve "X" given the car will GIVE them that much adjustment.
Now the OP said he removed 1/16" shim from each rear shim pack, so lets actually "see" what he did.

IF: the control arm shaft is to engine side he just decreased positive caster, moved camber to a more positive number and depending on which way steering arms are either changed toe to more in or out.
Now this is going from memory as i havent aligned an F body in year or so but IF my memory serves me its rear steer, BUT as my buddy who I just got off phone with it depends on bumpsteer in front end, weather it added or subtracted toe cause its camber curve and other factors have been addressed it may have toed it in.
I still see people doing alignments and not understanding the science behind it nor actually having worked the line doing alignments.
I also see people coming in and asking for "X" like OP, then open hood, see something shiny and start changing it but dont understand WHAT they are doing when doing it. THEN bash guy who just TRIED to do what you wanted on that piece of paper.
Hmmmm, seems to me he gets what he asked for, as far as CAR allowed, THEN changes something and thinks HE is genius,and tech is bumbling oaf.
Then people not understanding the angles attempt to "fix" everyones perception/opinion/ideas.
SO FOR REFERENCE:
TOE: The in our out orientation of front tire in relationship to rear of tire. TIRE WEAR CAUSING IF WRONG!
CAMBER: Inward(negative) tilt of tire centerline from true vertical through tire/wheel OR Outward (positive) tilt of tire/wheel from true vertical. TIRE WEAR CAUSING IF WRONG OR UNEVEN!
CASTER: The forward (negative) tilt from true vertical measured through upper/lower ball joint pivot points OR rearward (positive) tilt ie towards back of car with top of spindle.
Now on most older cars they had high ratio(18-1, 20-1) steering ration for easy, one finger driving w large steering wheel, narrow bias ply tires, mediocre geometry so instead of using positive caster which gives easier steering, better feel, better wheel return, they used negative caster or forward tilt to "dial" in mass produced feel AND long tire wear.

Now lets "fix" car with one or more of these : Guldstrand mod,tall ball joints, taller spindles, different control arms.
Install taller, wider , stickier tires, lower numerically ratio steering box, adjust/design out bumpsteer(honestly wish engineers had been more like Guldstrand and others in designing many cars,yeesh one car o know could have nearly 3/16" toe change and positive camber gain in turn was measured in miles by pics i saw) and now we need to change specs.
Get car to have negative camber gain on outside tire in turn and push specs to negative setting gets us better turning.
Get car turning with less than 4 turns on steering wheel to negotiate a curve means faster ratio steering,IE LESS turns of steering wheel to turn into corner.
NOW to get back easier steering better returnability when releasing wheel, we NOW need positive caster. when car has "straight up caster" IE same on both sides car will lead towards ditch as roads are graded towards ditch. Ever wonder wh road graders made rock roads high in middle? there ya go, so water runs off road.
Now this pitch is less on pavement but basic alignment knowledge is car will "pull or lead" to side with least positive caster. Hence we "add" more positive caster on passenger side , generally in .25-.50 more on pass setting.
Now CASTER IS NON TIRE WEARING ADJUSTMENT Hence the reason to use it to allow for road crown.
Now lazy alignment techs use CAMBER(remember its a tire wearing adjustment) to allow for road crown as most find cars with near symmetrical caster readings and if they dont have to do more adjusting why waste time.
Unless car simply wont drive right, do not split camber.
Not trying to be mean or anything, I just get little defensive about alignment tech bashing.
BUT if you know the 18 yr old HS punk is told to "get'er in tha green,,," is doing alignments with latest gee wiz golly gosh alignment machine, well time to move on to new shop.
True alignment techs follow rules, will follow as far as car had adjustment and manny can set you up shim packs for street and track specs, if you tack weld together then you can have two setups and only need toe setting jig.

[hotrodneb]

To clarify--
Setup--tubular control arms w/adjustable cross shafts (Gul mod), tall upper ball joint (1/2), tall tie rods, JGC steering box.

I went in with a printed out sheet asking for -1 Camber +5p +4.5d Caster 1/8 toe. I got -1p -2d Camber +3.8p +3.2d Caster 1/8 toe.
The tech stated 2 things- "I couldn't get more on driver's side" "I usually set cars like these there anyway"

So I start playing with it myself. Removing the 1/16 shims on the rear likely took off less than .5d Caster but also likely took me to a positive camber. This is what made the car feel a little more stable at highway, but less controllable in sweeping curves. Attempt #2 to add 1/16 and plus another 1/16 likely took me nearer to my original caster request and an out of spec camber, but also yielded an improved feel.

There was more caster available on both sides. This is the only small point in my original post. The tech meant well and was experienced, but MY requested specs were better for this setup and he "didn't know" what would work best. I have been on the other side of the customer giving me advice while they are paying me for my experience. This guy knew what he was doing, and works in a good shop that I trust. I would actually let him do it again.

[MonzaRacer]

Well for the record if the shim packs get too thick on onebolt the arm wont stay tight, also many times small adjustments like 1/16, 1/32 make odd jumps past a set reading.
As for moving .5 deg with single shim, doubtfull i will check alignment machine at work tuesday, if it has 68 f bird it should tell me what 1/16 shim will change.
Dont forget tire pressure, width, offset and many other things affect feel. Also when moving to a more modern , handling setup steering box setup is more important. If box has been in service for long time the preload might need small tweak too to bring center feel back but care needs to be taken doing that.