I got my car aligned today and I am not at all happy with how it drives.
Here are my particulars: 67 Barracuda. Aspen spindles. Offset UCA bushings set for max positive caster. Everything in the front end is new rubber Moog bushings. Wheels are late model mustang, 245/45/R17 tires

The alignment guy, who was recommended to me by another Mopar guy, said he could not hit the numbers I wanted. Here is what he actually did:
Caster: +1.7 degrees left, +1.6 degrees right
Camber: +.2 degrees left, +.5 degrees right
Toe: 30 degrees total

He said he could not get the caster numbers even close.

The car wanders and is freaky on grooved/patched roads. It needs more caster, right? I've done this same set up on two other cars it was never a problem to hit 2.5-3.5 degrees caster. Is it possible that the manufacturing tolerances on this car are way off? What should I be looking at first?

I just verified that the bushings in the upper arm are correctly orientated. Do I need to make sure the strut rod bushings aren't too thick?

Your rear ride height plays havoc good caster, lower the rear end down and you gain it back. I bet you 3 degree in droppin the rear down 2".

whats your ride height?

The back is actually pretty low due to worn out leaves. I matched the front to look good with the back...does the front end lose caster as it is lowered? Is it possible to raise the front and gain back some caster?

Sidenote: I can't measure ride height by checking heights on the LCA due to my wheels. So I set it with about 1" between the bump stop and the frame. I currently am using stock 318 torsion bars and stock bump stops. For stock bars, do I need more clearance between the stop and frame?

I hope the toe, at 30 degrees total, is a typo! It should be around 1/8" or 3/16" toe in. Positive camber is going the wrong way as you probably know... should be around .75 degree negative for a moderate handling application but that would not likely make it squirrly.

With caster at +1.6 degrees and toe set correctly it should drive OK at least with moderate tires. Factory caster was around 1 degree plus maximum. I wonder if something else is going on.

How about the bushings for the LCA and strut rod? Are you running poly? The poly LCA bushings can let the LCA float if the strut rod does not keep it pulled up snug. The poly strut rod bushings can be thicker compressed vs rubber and reduce caster and introduce slop. I had to fix this on mine with adjustable strut rods. "Before" the pivot on the left LCA had a 1/8" gap and the LCA was floating around on turns. Squirrly. Adjust the strut rod to pull it up snug and just a little more... not too much.

Okay...so I think I have a few things going on here. Today I pulled the upper arms and verified that the offset bushings are in the correct orientation. I then verified ride height by measuring points on the lower control arm. That was also good.

I will call the alignment shop next week and ask about the toe in.

The tires I have on the car are used and I'm starting to think they need to wear in a bit or I need new tires. I drove the car more today and it seems to be tracking better now as I drive it.

I probably need to invest in some tubular upper arms to get the caster numbers more to my liking.

Bushings are all Moog rubber.

Last year, a buddy took my advice on these Moog bushings. I have used them in several cars to obtain additional caster. My 70 Charger has stock UCAs, reinforced stock LCAs, stock strut rods with poly bushings and was able to get over 4 degrees positive caster with .75 NEG camber. It steers and handles great. My friend has a 71 Road Runner with essentially the same front suspension. I installed the Moog bushings in his car and the alignment guy couldn't get more than 1.5 degrees of caster. I had a hunch about that and after some research, I learned the following: ALL production cars are built with the intention of being the same, yet they are also allowed a small range of tolerance for most everything. If you have ever built an engine, you surely recall there being an acceptable range for the bearing clearance, the piston ring end gaps, etc. Imagine the frame rails, the K member, the UCAs, the strut rods are built to measure within an acceptable range as well. In a perfect world, all cars would have parts right in the middle of every "tolerance" range. It stands to reason that some might have been built where all the parts ended up at one end of the tolerance or the other. This would explain how some cars align so easily while others have trouble. The caster numbers that I have may be the result of "all stars in alignment" as some say. Your car may be one built at the other end of the tolerances. The tubular upper control arms may be what you need.

The caster numbers are the only ones good enough (for now) in this topic. But still the focus 'on correcting' them seems to lies there, while the camber numbers need to be fixed and the toe-in number is one big questionmark.

Why not simply measure toe-in yourself on the driveway to get a number that makes a bit more sense.

By the way, if you removed the A-arms to check the orientation of the bushings, your entire wheel adjustment is off in the weeds again now.

today's toe is measured in degrees on all the alignment machines i am aware of, and the FSM's calls for this measurement since at least the mid 90's. a typical measurement is around -10*, so if the op says his is at 60* [i forget just what was stated], then i'm inclined to believe that indicates it is toed out, which would cause the twitchyness he is experiencing. the positive camber doesn't help either. i asked at one time what the conversion factor was for toe degrees to inches, but i can't remember if i got an answer, or if i forgot to write it down [which would be the more likely outcome].

just looked. toe was stated at 30* total. that is most likely a toe out setting, unless the "-" was omitted. sorry. "old timers disease" at work........

Can you post a picture of both your bushings in the arms and the cam bolts as aligned?

I've had an alignment guy tell me he couldn't get the numbers I wanted. I had to tell him how to do it.

I did the math on the toe to convert inches to angles. Bottom line 0.3 degrees total toe in would be about 1/16" toe in. Not enough. Suggest you need at least 1/8" or .55 degrees total toe in for stability. .8 degrees would even be OK.

Agree the alignment is suspect. Best with MOPARs is to first set the eccentrics for maximum positive caster ignoring all other measurements. Then check it. Then adjust to dial in some negative caster and get it close side to side. Then set the toe.

Total Toe In Total Angle Deg
0 0.00
1/16 0.28
1/8 0.55
3/16 0.83
1/4 1.10

'negative camber'

I prefer zero toe
7-8.5 caster
-1.5 to -2.5 camber (depending on tires)

ok, thanks ! i will put this some place i can reference to in the future. BUT, is this degree measurement in toe IN stated as a "plus" or a "minus" number ? that is still confusing to me. help an old guy out here please !

Using what diameter tire? The diameter will impact this measurement.



Again, these aren't universal because of variations in tire diameter. They may get you close but won't be exact due to these variations. IMO, toe is easy enough to set in inches, why do gyrations to convert to degrees unless you are decifering a spec sheet.

Positive numbers in toe generally refer to a toe in position. Negatives would be toe out.

ok. negative is TOE OUT. why, oh why, did the manufacturers go to degrees ????? i realize tires are the critical thing in this measurement ! one thing i learned is NOW i know what the degree deal is when i have to set my minivan and my wife's concorde. and just for the record, i always try for around 1/16"-3/16" TOE IN for a start point on everything. more on a front steer vehicle than on a rear steer. just my preference.

Yes... tire diameter matters in the calcs. I assumed a 26" tire diameter for the calcs (close to stock). I can re-run with other diameters if somebody wants to know.

As far as how much toe to run I think it is application and driver dependent. Auto X'ers often run some toe out to facilitate fast turning. Toe in promotes stability... which the OP was lacking... thus the suggestion to go with factory specs for toe in. Also, a little toe in compensates for the road force that is "stretching" the steering linkage as you roll and trying to toe the tires out. The idea being you want the tires to be almost straight at speed.

Before I installed the Hotchkis upper control arms, I was having trouble getting the positive caster and the negative camber that I wanted. I was able to get the desired specs by installing spacer washers like these: http://www.manciniracing.com/caspki.html

You start an alignment by setting ride height, and then set max positive caster with the cams. This is done by moving the rear cam towards the engine and the front cam towards the fender. This results in positive camber as well.
The next step is to move the front cam in to get the proper negative caster. When you move the front cam back towards the engine you lose some of the positive caster. The spacer washers give you the proper negative camber without moving the front cam back in.
It's a time consuming process... In the end I stepped up to the Hotchkis control arms, and could not be happier.

Sorry, didn't check this thread for a couple days.

Looking at the print out from the shop, it appears that they currently have me toe-out in the front. I think this is the main problem. I have an appointment for tomorrow and I am going to have them fix the toe. If possible, I am going to have them add in negative camber and not worry as much about the caster.

In the future, this car will need aftermarket UCAs and possibly spacers on the lower ball joint to hit the camber numbers.

Will report back after tomorrow.

Thanks for the responses.

Toe out? What kind of hack mechanic thinks that a street car would benefit from toe out?

I hope they treat you better next time you are there.