Wheel Alignment

[stevensonmotors]

Hello
Im at a loss on how to do a front wheel alignment on my 59 Apache 3100 I just bought a new straight axel and tie rod ends. Any help would be awesome.
Thank you

[roger55]

I just am getting my truck on the road after a ground-up restomod. (Stock axle, new stock leaf springs, CPP 400 power steering, their tie rod with the updated ends and disc brake kit for 6 lugs.)

I had the alignment done last Thursday. They did an awesome job. The shop owner has worked there since 1968 and bought the shop in 1987. He knows how to do these old trucks as he owns '58 and '59 Chevy trucks as well as '55 and '57 Bel Airs. Anyway he told me if I go 3 degrees or over on caster it will make the bump steer worse. He said he would adjust my shims to get what he thought was the best setting for drivabilty with my power steering while keeping the bump steer down. He confidently said "I know exactly the setting that will work best for you."

He put his best guy on my truck but the owner was really doing most of the work. I think he was interested in the opportunity to get his guy more familiar with the old trucks.

I had made a guess and installed 3 degree shims in it when I put it together and it turns out it was a pretty close guess. I brought some other shims I had with me which were a couple of 1 degree shims and a 2 degree one.

He took these shims and shifted them around until he got what he was exactly looking for which was 2.6 degrees positive camber on the right and 2.1 degrees on the left. He wanted them exactly 1/2 of degree apart and got it. He got that with a 3 degree shim on the right and a 2 degree on the left.
They then set the toe to 3/32 in and were done. Btw, this was a brand new $40K alignment machine. He said the platforms run an additional $22K also.

I bet it would a be few and far between number of alignment shops that would be willing to undo the u-bolts on the springs to change out shims to get perfect caster adjustment. And do it for their normal front alignment price to boot ($70).

He said my camber was absolutely perfect. It's non-adjustable for any straight axle and just means the axle is not bent in any way.

It drives really good so far. The steering has no play and it goes straight down the road. But it will of course always have the qualities of a straight axle with front leaf springs. The bumps will bounce you some. You know the feeling if you ever driven one before. I haven't driven it on the highway yet but I did take it up to about 65 on the access road. Tomorrow I'm getting the Texas safety inspection and then licensed so I'll be test driving a bunch this coming week.

[mr48chev]

There isn't much to set on one. At least that you set in your home garage.

I am assuming you understand the basics of Caster / Camber and Toe in so I won't go into the basics of it.

Unless the axle is tweaked camber is pre set. If it is a used axle from a donor rig it might be off but you will have to take the truck to a shop that can adjust the right camber into the axle if it is. If it is a dropped axle from Sid it should be all set to go.

On caster if it has to be adjusted you use a caster wedge between the axle and spring to change the caster to what you want. There is a balance between tracking really well at higher speeds and steering effort though. Personally I'd put it together, set the toe in and then drive it and see how it feels and go from there. If it tracks well and the wheel comes back to center after a turn and the steering effort is ok don't fuss with it. If it doesn't want to track well you will need to do a caster change. I wouldn't go much over 3 degrees + caster though.

This is how I set toe in when I don't have a front end machine that gives a toe in readout.

I raise each wheel and with something to steady my hand in front of the tire I hold a pencil lead to the tire and spin the tire so that I get a line around the center of the tread. Do that on both tires and set the front tires back on the shop floor.
get your helper to hold the end of the tape measure on the line on the front or rear side of one tire while you measure on the line you drew on the other tire. then measure on the other side (front or rear at the same height you measured at the first measurement. You want between 1/16 and 3/16 toe in. Meaning that the front measurement is that much less than the rear measurement.

On the tire rod ends I'd probably start on the bench by counting the turns I screwed each tie rod end onto the tie rod and then back each one out half of the total turns as a starting point. That will give you equal adjustment in or out.

[stevensonmotors]

Thanks guys
I do not have the cpp 400 box installed yet so for now where can I get the shims at I have never used or installed them.

[roger55]

It might be worth it to you to drive to San Angelo with it and get it done here.
They don't have shims though so you would have to bring your own.

[stevensonmotors]

Thank you for the tip I just found the caster wedges on line so i guess i can just buy the ones i think i may need.

[mr48chev]

Caster wedges should be available at most any real parts house. you can also find them at 4x4 shops but I would suggest not buying them until you find out if you need them and what degree change you need to make They come in a number of different degrees and you use the one you need and never stack them.

[roger55]

Originally Posted by mr48chev

Caster wedges should be available at most any real parts house. you can also find them at 4x4 shops but I would suggest not buying them until you find out if you need them and what degree change you need to make They come in a number of different degrees and you use the one you need and never stack them.

Unless you go to a alignment shop like mine where they didn't have any but were very willing to tweak it to exactly where you want it.

I was lucky that I had what was needed and I didn't have that many. I wonder if the O.P. can expect that his will be close to mine?

I was lucky that I had what was needed. I estimated well when I bought the 3 degree shims although I had the others laying around already.

[mr48chev]

My line of thinking is that because it is a hit and miss proposition on what you need if you need any caster wedge at all and that you have to assemble the truck and then check to see what you need it's more prudent to just figure what you need and buy those than buying something on a WAG before you put the truck together. I don't mind spending money on what I need but it gets tiresome taking something I bought in anticipation back or worse yet adding it to the collection of other pieces I have bought over the years and didn't use but didn't take or send back.
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[roger55]

Since he's using a power steering box, he's going to want some positive caster.

I would think that all these axles are built the same way but I can't know that. Assuming they are, the only other thing would affect caster would be a weight difference between the front and rear spring mounts. You wouldn't think that would vary that much from truck-to-truck.

If I were him, I'd start out with 3 degree shims as a starting point same as I did. If the shop he uses has a selection of some kind or they are available locally and quickly while the truck stays on the alignment machine so you could go buy them then I agree that it would be best not to guess and buy any before hand.
I'm thinking 2" shims would be hard to find locally though.

[mr48chev]

That's all well and good in theory Roger but as a former front end alignment specialist with a lot of years of experience behind me fact tells me that you don't just go out and throw in an X degree caster wedge just because you think it possibly may have 0 caster with no wedge. The truck may have a couple of degrees caster with just the springs and no wedges. My argument for him is to not spend money on wedges until he or his front end guy knows what exact wedge he needs so he only hopefully spends the money once. This isn't like sticking a few shims behind the control arm shafts on an S-10 or Camaro front end after you redid it because X # of shims usually gets it in the ball park and you go from there.

[1958Warrior]

Sounds like the best thing to do is do a little research and call around to the shops to verify they have wedge shims available in stock and if they have any experience working with straight axles. Also, call a few of the local hot rod shops see if they can recommend a shop.
Also ask a few of the members that are here local, running straight axles who they would recommend.

[1project2many]

I agree with not buying parts you don't need, but if I'm having the truck put on the rack I'd try to be nice to the alignment guy and bring shims with me. I'd stop in at the friendly parts store and ask if they'd let me buy a selection of shims then return the unused ones. They're not that much $$.

[mr48chev]

That's a possibility if the shop doesn't keep wedges in stock.

On checking the alignment. Any front end alignment shop can check the alignment and tell you what it is setting at. They may not know squat about how to change the camber on an I beam or even put the wedges in to adjust the caster but they can check the alignment and give you the numbers on caster, camber and toe in. Problem is that most of them now charge for putting the vehicle on the machine even if they don't make any adjustments.

Shops that deal with trucks or motorhomes are usually your best bet for an I beam rig. As often as not it's the same shop that also rebuilds springs or builds or sells new springs.

[tmoble]

I have a couple bronze caster shims left over from when I rebuilt the axle on my truck. Free to a good home, PM me if you need them. If you already have some please let them go to somebody who has none.

I wonder what that front end guy thinks the term "bump steer" means. I don't see how you could have bump steer on a solid axle. Sort of a contradiction in terms. AFAIK bump steer is when the toe-in changes during suspension travel. Not going to happen with a straight axle unless there's bad parts or something.

[roger55]

I don't think so Tom. I think it has to do with the steering geometry and how it affects the relationship of the tie rod and drag link.

And btw, he didn't use the term bump steer. That was me. He just said that 3 degrees or more of positive caster gives undesirable effects.

[mr48chev]

"Bump" steer on an I beam or tube axle often relates to a Ford cross leaf setup where the drag link and radius rods are not parallel with each other. You can see a mild case of it on my old T bucket that I built in the early 70's when there was little discussion on the subject and the hot lick at the time was to run a lot of caster to have the car track at speed. When the wheels and axle moved up and down even the slight amount that they did usually move it was real noticeable at the steering wheel when I think back on it.
Don't laugh too hard I had all of 600 1975 dollars in it as it sat. The carpet interior was because one of my friends had a custom van shop and had left over carpet.


With the leaves removed from the front end of my 48 the angle of the drag link is really off and it gets the bump steer a lot worse than the T did.

[stevensonmotors]

Originally Posted by tmoble

I have a couple bronze caster shims left over from when I rebuilt the axle on my truck. Free to a good home, PM me if you need them. If you already have some please let them go to somebody who has none.

I wonder what that front end guy thinks the term "bump steer" means. I don't see how you could have bump steer on a solid axle. Sort of a contradiction in terms. AFAIK bump steer is when the toe-in changes during suspension travel. Not going to happen with a straight axle unless there's bad parts or something.

Posted via Mobile Device

[tmoble]

stevenson, replied to your PM. It didn't have your address in it, sometimes phones and tablets don't do well with PMs, might have to use a regular computer.

[tmoble]

Mr48, bet that was a fun car. hard to do anything that simple anymore.

[chevyguyase]

2 kinds of fools in the world, those that give advise, and those that take it. But here goes, my 2 cents worth "If it were my truck" I'd put it together without the shims. The axle is designed with caster & camber built in, but it's old and the roads weren't very good back in the day & may have even been in a wreck, and may be a little askew, so you really don't know what you have yet. If your using radial tires, they like a little more caster. If you turn a corner and the steering wheel doesn't return to straight ahead, you need more caster. If the truck drives well I would still take it to an alignment shop and see where I stand with the measurements. Make sure your truck is finished, wheels, tires, and especially rear axle suspension height which directly effects your caster. They will give you a print out and make recommendations. Camber and toe in are the biggies,( tire destroyers) I would just make sure the caster was positive and within 1 degree of each other. A little positive camber and 1/4 inch toe and your good to go. I'm a retired Chevrolet master mechanic (42 years) for what it's worth.

[tmoble]

good advice there.

1/4" toe in? seems like a lot.

[Cape Codder]

I did alignment work for a truck dealer years ago. Camber was adjustable by use of a bottle jack and chaining the axle to the rack. A little heat too. As far as caster I was told the lighter the rig the more caster you could run. Look at the old rail dragster front ends with the axle layed way back. Just let go of the wheel and it centered. A light vehicle without caster will tend to wander at speed.

[1project2many]

A little heat too.

As long as it's not glowing. Heating a forged axle is not recommended.

[tmoble]

stevenson, still have not gotten any mailing address from you?