Trying to get alignment done on a '55 tbird

W

wex65

Senior Member
Took the car in this morning for an alignment and even brought a print out showing the specs and some shims.

90 mins later they admitted defeat.

They DID manage to get the toe adjusted but said the camber was 'complicated' and would take a 3 hour appointment.

Annoying as the $85 they charged me just to do the toe will be voided once they change the camber. The toe will need redoing then....

So, decided to do it myself. Ordered a Maximum Motorsports camber/caster tool and will be ready once that arrives.

My one question...how do you (or CAN you?) adjust the caster on these cars?

The camber is obviously changed via the shims (why they couldn't do it is beyond me) and the toe via the tie rod ends. But the caster...?
 
Ok, this is a real memory test. I don't recall any shims on the upper or lower A arm bushings, although I remember reading a discussion of being able to move them slightly on initial assembly.

First, you shim the front or rear of the upper A arm. Moving the base of that "triangle" moves the peak (the ball joint) slightly forwards or backwards. When you get your castor reading, then you shim both front and back, pulling the base in, until you've got the camber. Then, recheck the castor. Fiddle as necessary.

It doesn't surprise me that a shop that isn't used to old cars couldn't do this. The old timers did it almost like magic to get everything inside spec. Around here we've got a couple shops that do everybody's old cars. When they retire, we're out of luck.

My 55 bird would just barely make it into spec for castor/camber, even with all new bushings, etc. The castor spec is way less than a modern car, aimed more at turning effort than self centering. Before radial tires, too.
 
When I put radials on my Merc the 1st thing I noticed was that I had to lightly "assist" the wheel to self-center. With the bias ply tires I had before I could pretty much just let go of the wheel when coming out of a turn and it would center itself with little or no input from me. I consider that a small sacrifice compared to the benefits of running radials.
 
Many thanks guys. I thought about it for a minute and can see how first adding shims at the front only would tilt the axis back, giving it caster. Then, adding both front and back simultaneously to affect the camber.

I will have at it once the camber/caster tool arrives next week.

Thanks again.
 
Just went through this on my 61 Starliner. Im interested in knowing how your alignment tool works for you. I ended up going to the hardware store and picking up an angle finder. I made turning tables out of 1/4in plywood with a little grease between them. Don't know about the tool you bought but I know I can't ck caster with my set up. The specs on mine were 1*+ camber and 1/4* to 1/2* caster. I figured after I set camber and ckd the toe out on turns if it didn't read off the scale, pulled or wouldn't return after turning I wouldn't mess with it. Changing caster more + on mine is achieved by removing shims on the front if I recall correctly. I was chasing a bad pull to the right that no amount of adding caster or camber would correct. My pull ended up being the ps control valve not adjusted correctly. After chasing this for 2 days a 1/4 turn to the adjustment nut on the control valve fixed the pull. Set the camber to 1*, adjusted toe in using the jack stand/string method. Drives down the road straight now. Recovers good on left turns not so much on right turns but I can live with it.
 
This is the tool I bought. It helps with both camber and caster according to their site.

http://www.maximummotorsports.com/Camber-Gauge-P192.aspx

I will be following the procedures described int he link below:

http://www.hotrod.com/how-to/chassis-suspension/hrdp-0411-wheel-alignment-guide/

I will let you know how I get on. the tool should arrive here Thursday so looks like a job for next weekend.



LOWRIDER said:
Just went through this on my 61 Starliner. Im interested in knowing how your alignment tool works for you. I ended up going to the hardware store and picking up an angle finder. I made turning tables out of 1/4in plywood with a little grease between them. Don't know about the tool you bought but I know I can't ck caster with my set up. The specs on mine were 1*+ camber and 1/4* to 1/2* caster. I figured after I set camber and ckd the toe out on turns if it didn't read off the scale, pulled or wouldn't return after turning I wouldn't mess with it. Changing caster more + on mine is achieved by removing shims on the front if I recall correctly. I was chasing a bad pull to the right that no amount of adding caster or camber would correct. My pull ended up being the ps control valve not adjusted correctly. After chasing this for 2 days a 1/4 turn to the adjustment nut on the control valve fixed the pull. Set the camber to 1*, adjusted toe in using the jack stand/string method. Drives down the road straight now. Recovers good on left turns not so much on right turns but I can live with it.
Click to expand...
 
Does the 'Bird's upper arm look anything like this? Which is a '59 Ford. Add shims equally to make the camber more positive. Caster is done by moving the shims fore and aft, if you move a shim from the front to the back ( and vice versa), the camber stays the same, but the caster changes.
 

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The arm looks a lot like that, but I don't know if they're the same. The upper arms in my bird came from a pass car, so I know they're the same.

You may be right about setting the camber first, and then the camber. As I said, it's been a long time. What I remember for sure is they interact, and getting all the castor I wanted stopped me from being able to set the camber. "Fiddle as necessary" is what I recall.

Look a little closer. Adding shims at the front mounting bolt decreases castor, I think. Back lean, top ball joint behind the lower ball joint looking from the side of the car, is what creates self centering or tracking.

Dobie, I remember when radials first came out. I think the old timers figured out the toe in had to change. Less, I think, but it's been years. Don't know if that would impact your return to center or not.
 
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Surprised that shops have no clue what to do with a shim car (wait until they run into a '64 T-Bird...).

On a symmetrical arm jockeying the shims to and fro changes the caster only and not the camber. It does have a very minimal change on the toe, but we did check it every time.

The car will pull towards the side of most negative caster, aka the leading upper ball joint. We always aligned a car by the numbers in the book. If a pull was present, we moved the shims around accordingly.

Old GM products with no shims, I would put some shims in at the upper arm (if I had the car apart that far) so I could get the pull out without going back up on the rack.

About the toe, with bias ply tires, those had a tendency to toe outward once it was rolling, so we set them 1/16" to 1/8" in. Same car with radials (those got popular around 1975) we'd set the toe between 0-1/16" in. This should get the wheel to center by itself, if not, look at how tight the steering box and drag link are set.

And shoot... I am now an old timer. I learned front end alignments in college about 1974 and I was working along side with a guy who was doing alignments for 15 years. Every morning we would set the toe attachment to the rack (Bear equipment) and it was becoming evident to me that this guy was setting the toe wrong for 15 years. I would hear the customer complaints about the steering wheel being off all the time. A short time later, his big mouth got him fired and the rack was all mine.
 
Bob, as one old timer to another, thanks for that post. Clears up some of the stuff I couldn't remember or had wrong. Now if I can just remember it tomorrow.......
 
The last car I ever professionally aligned was a 1980 something. I did lots of old cars over the years and was known for my work on Cadillacs, I had a following. I did taxi cabs, ambulances, drag cars, stock cars and so on.

Most of the geometry is common sense, how it moves. We did go by factory charts, but I learned fast that there are exceptions to the rule. If a tire wore excessively on the inside (low camber) and it was within specs, I'd give it a 1/2 degree more.
 
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