[Rick_L]

If you can access it to make a measurement that will work.

How are you going to access that for a measurement with the wheel and tire in place and on the ground? You have to make this check at ride height.

Positive caster is when the upper ball joint is to the rear of the car compared to the lower ball joint.

 

[55 carman]

Thanks Rick that's what I was thinking but wasn't sure.
Yes I'm making all measurement on level floor with car sitting on the tires.
My jig is rather crude but it stays true. The Allen bolts I use on spindles, caster and the beem clamps I use on the outer wheel lip, camber.

It's not to bad to get to the front of the spindles while laying on the floor in front of the car. Ive double checked my reading after several short test drives and keep getting the same numbers. 5 degrees positive caster L R 1/2 positive camber LR 3/8 toe. Ron

 

[Drumbum675]

This comes up so frequently, decided to make it a sticky:

Stock specs
Camber Degrees......0º to +1º
Caster Degrees........0º +/- 1/2º
Toe In....................1/16" to 3/8"

The biggest deal here is the caster. Positive caster is what makes your car track straight down the road and makes the steering wheel return to center when exiting a turn. It also makes the steering effort harder.

With all stock front end parts +1º caster is about all you can hope for, and some cars don't have that much adjustment.

With manual steering, as much postive caster as you can adjust for is about all you should do, as more will make the steering too hard.

With power steering, do the same with a stock front end. You can get 3-5º more caster with aftermarket tubular upper control arms. It's a good mod.

Another way to get more caster (or camber if you can't remove any more shims) is to use offset upper control arm shafts. They'll usually get you an extra 1º - 1-1/2º

On the camber, zero or even slightly negative is a small plus for cornering.

On the toe in, the shop manual says 1/8" -3/16", but that was superseded by a factory bulletin in the mid 50s. Radial tires will definitely not want much toe in.

The above deviations from the stock specs are my opinion. I think most agree with the general nature of them, but some may have their own ideas on the details.

So I'm almost ready to get alignment done. I'm going to let a shop do it, but I want to make sure I give them the proper numbers. I've got CPP tubular upper arms, stock lower arms with a CPP500 box. So, based on what I've read my numbers should be:

Camber 0 degrees

Caster +5 degrees

Toe in 1/16" to 3/8"

Is this correct?

 

[MONK]

How big a job is it to replace the cross shafts?......what's all involved?

 

[55 carman]

How big a job is it to replace the cross shafts?......what's all involved?

If your replacing them to gain caster it might not be a bad idea to install the new A-arm with + 5 built in.
You can get with rubber or poly bushing. Love your car! Hope to see you next august at the Tri-five Nationals.

 

[MONK]

Nice..........thanks

 

[gman]

This comes up so frequently, decided to make it a sticky:

Stock specs
Camber Degrees......0º to +1º
Caster Degrees........0º +/- 1/2º
Toe In....................1/16" to 3/8"

The biggest deal here is the caster. Positive caster is what makes your car track straight down the road and makes the steering wheel return to center when exiting a turn. It also makes the steering effort harder.

With all stock front end parts +1º caster is about all you can hope for, and some cars don't have that much adjustment.

With manual steering, as much postive caster as you can adjust for is about all you should do, as more will make the steering too hard.

With power steering, do the same with a stock front end. You can get 3-5º more caster with aftermarket tubular upper control arms. It's a good mod.

Another way to get more caster (or camber if you can't remove any more shims) is to use offset upper control arm shafts. They'll usually get you an extra 1º - 1-1/2º

On the camber, zero or even slightly negative is a small plus for cornering.

On the toe in, the shop manual says 1/8" -3/16", but that was superseded by a factory bulletin in the mid 50s. Radial tires will definitely not want much toe in.

The above deviations from the stock specs are my opinion. I think most agree with the general nature of them, but some may have their own ideas on the details.

since this is a sticky, thought I would ask the question here. My 55 Belair has stock, manual steering. I am planning on rebuilding the front end with the stock kit, including springs and rubber bushings from Ecklers. I run radial tires. I read where adding caster helps power steering systems. should I worry about changing the A-arm shafts or shafts with those with increased caster, or just plan on utilizing the stock arms and shafts (assuming they are good and not bent)? I know I can go shafts or A-arms with increased caster, but is it needed with the manual steering? Haven't torn it apart yet, so don't know the condition of the a-arm shafts, and whether I need to replace them or not. also, heard that Poly bushings will give you a squeak. is it best to stick with the rubber bushings?

 

[wyonker]

Ricks information is spot on by my experience as a frame and front end tech from years gone by. I probably aligned thousands of 55-57 Chevys over the years when they were daily drivers for non car enthusiasts. His advice about radial tire toe is also right since radials have far less rolling resistance to side resistance ratio than bias tires. Too much toe will scrub radials faster than bias. Keep on mind my experience was mostly on original vehicles with lots of daily wear and the requirements for your new-tech higher performance builds result in the need for higher caster. I just put my 57 on the road first time in 28 years with lots of these upgrades and am having to learn to make it drive well with the combination of old and new tech, sorting it out is very satisfying.

 

[halftimer]

The toe spec. Is total toe correct? 1/16 perside equal 1/8total toe:anim_25:

 

[BamaNomad]

I had to replace the upper control arm on the DS, along with ball joints, etc this past year... Not having driven the car much, I didn't realize how much alignment change this could make until I drove it the past few days in preparing to go to KY... The alignment is *off*.. I thought it felt like it was 'toed out' too far, but a personal measurement (my wife and I using flat boards against the tires, showed 'toe in' amounting to about 3/8"+ ... Will this much toe in affect steering/handling? I thought 0-1/8" was the right number until reading this string and finding someone's recommendation for 3/8" Toe In...??

I went to SIX (6) different alignment shops the past 2 days, and NONE of them could do an alignment on my car (lowered 2" all around with aftermarket wheels and 235-70/15 ARE torque thrust wheels). Apparently NONE of the modern machines can do a 'front only' alignment, and their rear wheel 'tools' would NOT fit under the wheelwell lip, nor allow the wheel to be rotated 90 deg while installed. Apparently the newer machines have NO option for 'front only'. It's looking like 'home garage alignment' is the only answer???

 

[techman441]

I have always set the caster first then set the camber, caster set with 1/2* more negative on driver side, 1/8 in total toe in unless with wide tires then 3/16 toe in...

 

[iequipu]

Hey BAMA I Have worked for John Bean/Snap-on for over twenty years and all of our machines will do a front end alignment using only front wheel clamps .So ask around and see who has a John Bean Aligner.

 

[fiftyfivechevy]

.33° total toe in to inches

That calculates out to exactly 5/32" toe-in or exactly half way between 1/8" and 3/16" which should be ideal. The factory recommendation is based on the original size tires which were a lot smaller in diameter and width. Most people nowadays have much larger diameter and wider wheels which theoretically may call for a little more toe-in, but in reality, it doesn't really matter, unless you have worn parts in your steering, such as loose ball joints, tie-rod ends, etc. The guy who did your toe-in knew what he was doing

The math is: Tan .330°/2 per wheel x wheel diameter (27) x 2 for total.
(I used 27" wheel diameter as a reference) = .156" or 5/32". Yea, I know it could have been simpler, I was just trying to show the entire step from per side (.165°) toe-in to the total (.330°) toe-in.

FYI: My method for doing toe-in is pretty simple. I bought (2) 6' rulers at Harbor Freight at $6 apiece and (2) pcs of large bead chain (key chain) on Ebay. I simply place one of the rulers in front of the tires, and the other ruler behind the tires, drop the bead chain in the outside tire groove which is the easiest on each side of the car. Then I move the rulers to get them to zero on one side, and then go to the other side to see the readings. Subtract the smaller reading in the front from the larger reading in the back and you have the total toe-in. By cutting the bead chain a little short of being able to touch the rulers it is simply a matter or sliding the chain up and down to almost touch the rulers to get an accurate toe-in reading. You can get it dead nuts if you take your time. Three cautions: 1. Don't do in on a windy day, it causes the bead chain to move around which could cause an error, and 2. Make sure you don't accidentally start the bead chain in one tread groove and switch it to another as you go around the tire. 3. Make sure the rulers are straight across in the same relative position to the tire. IF you have one of them at a noticeable angle, you will have an error. Centering the steering wheel is the biggest problem. It drives me nuts if it isn't perfectly set horizontal when the car is going in a straight line.

NOTE: If you can't get bead chain, use large diameter string with small plumb bobs on the 4 ends.

I have checked my toe-in numerous times after driving and it always checks the way I set it. Modern tires are made in very accurate molds and the bead chain centers itself in the groove.

fiftyfivechevy

 

[Rick_L]

A couple of comments here.

After all this time, the original toe in spec is a typo. It should be 3/16" maximum, not 3/8". The factory made that recommendation even smaller through bulletin. Radial tires want even less toe in. 1/16" - 1/8".

I don't see how you can set caster first and then camber. It makes more sense to me to set the camber then the caster. But that's just the way my mind works and maybe you can do caster first and keep it all straight. One reason to do it that way is that on most 55-57s you are limited by the number of shims. In other words, to get proper camber you may not have much thickness of shims. This limits your caster adjustment. If you tried to set caster first, you may not be able to get the camber you need. I hope that makes sense.

 

[Rick_L]

FWIW, the question was asked, "are the specs total toe-in, or individual for each wheel?"

These old cars are spec'd for total toe-in for the pair of wheels. Modern cars are usually spec'd by an angle for each wheel. It goes back to the way it's measured. You measure the difference between the wheels for the former, you measure each wheel for the latter.

 

[Pops @ Tri-5.com]

Rick...I searched through my Chevrolet Service News bulletins and found the paragraph below that addresses toe-in change in one dated March 1956...However, that was for bias ply tires...With today's radials, the chart in post #1 is correct...Toe-in today should be 1/16" to 1/8" total.

 

[cortcomp]

I know this thread is old, i've re-read it 10 times but i'm not 100% what i should go to the shop with.

56 210 4 door, borgeson 600 box, not too wide radial tires 15", stock height minus one coil, cpp tubular control arms with extra caster.

Would i hand them these directions to aim for?

Caster: 3.5
Camber: pass -.25 driver 0
toe: 1/16 to 1/8
steering axis inclination: 3.5-4.5

I feel like reading here on camber, i'd say +.5, so that'd be +1/4 degree per side. Then you guys mention making it more on one side than the other, wouldn't that be 0 and +.25? But on the PDF linked earlier in the thread, it used the negative and 0 camber above? Doesn't that affect higher speed handling?

I kind of understand what we're discussing here, i don't want the car running downhill, some of the roads here can be annoyingly crowned, most are average though.

What i want to make sure is that i give them the exact correct dimensions, even if i don't understand why they're correct, because the shop will align exactly to what i say, even i don't know why i'm saying it.

Thanks all!

 

[Rick_L]

I know that some say to have split camber, but this never made sense to me. I like split caster to try to get the car to track on crowned roads. This means 1/4 - 1/2 degree more caster on the passenger side than the driver side.

Though the stock spec is 0 to +1 degree camber, there will be a slight benefit to cornering if camber was up to 1/2 degree negative.

The thing about using plus/minus numbers alone is that you're ignoring the effects of where the adjustment is on the other side of the car. For instance if you just put caster in the +/- spec but the driver side has more caster, then the car will try to run toward the shoulder.

The toe-in was discussed pretty thoroughly in the last few posts.

Once you're down to 1/4 or 1/2 degree increments, that's really fine detail and may be close to the accuracy and repeatability of measurement. And maybe beyond the level of detail that an alignment tech will put into the job.

 

[cortcomp]

The cornering i'm not as concerned about but i do want straight tracking and not feeling "dicey" when i'm up around 75-85mph. (being a daily driver, i'm not canyon carving with a 4 door but i do drive some highway.) I felt like i read negative camber was noticing the car jumping to the side some at highway speeds when hitting bumps or whatnot? I definitely get that now, and some of the "knife's edge" feel at around 75mph.


Would better directions to them be more in line with:

Caster: Around 3.5 positive total (Drivers 1.5 - Pass 2.0)
Camber: +.5, (.350 each side)
Toe: 1/16
Steering axis inclination: +3.5 to +4.5


The inclination i got off of the linked PDF, do you even give them that or do aligning the caster/camber/toe result in the correct steering axis? I've never asked for specifics there. I don't want to give them un-obtainable numbers or something that is like "Well yeah, if you gave me these that MEANS this" and look like a moron.

 

[Rick_L]

Only toe-in is total. Do not add caster or camber to get a total. I.e. your caster should be 3.5 degrees on passenger side, 3.25 degrees on driver side.

Steering axis inclination is built in to the way the spindle is manufactured. This is the angle of a line drawn through the ball joints when viewing from the front of the car. It is 3.5 degrees on a 55-57 car, inboard at the top. Some alignment machines give you a steering axis inclination on the printout. It is simply the algebraic sum of camber and inclination angle. As an example, with +1 camber, your inclination angle would be (-3.5 + 1) = -2.5 degrees. I personally think this is misleading and confusing. The spindle is not going to change unless it gets bent in a wreck. Camber is a direct measurement that affects the tire patch on the road.

If you are worried about camber making your car "dart around" have them set it at zero.

But more important, positive caster is what makes the car track straight and true, not camber. It also helps in restoring the steering to straight ahead when exiting a turn.

Last thing, you can't get 3.5 degrees positive caster with a totally stock front end. Maybe +1 degree, some cars less. You need aftermarket upper control arms, offset upper control arm shafts, or modifications to the upper control arm mounting brackets to get more.