alignment opinions.

Tommy the Cat · Dec 15, 2019

Aftermarket arms typically have at least 3 degrees positive caster built in...

oldcutlass · Dec 15, 2019

You need more caster, you should be closer to +5* even on both wheels. Your camber is perfect. I like to see between .0625 and .125 total toe.

temp2c · Dec 15, 2019

67_LS1 said:
I too had a recent front end alignment and now it feels real “twitchy”. Lots of steering wheel movement to keep the car straight.
I don’t have the alignment readout with me, it’s at my shop but I’ll check it later.
Are your recommended specs for use with the taller ball joints or just Chevelles in general? I have full Hotchkis suspension and sway bars and dropped spindles.
I’m wondering if I should go back and have it done again.

You can post the alignment sheet we can all take a look.

Frankly it sounds like toe, its either in or out too far.. If you show the sheet I can tell you what shims to move and how many turns to give the tie rods..

The specs I gave above are for cars with the SC&C set up.. I'm not sure about your set up..

Does you set up add positive caster?

Does your car favor one side of the road or pull to one side?

67_LS1 · Dec 15, 2019

hydro462 said:
You can post the alignment sheet we can all take a look.

Frankly it sounds like toe, its either in or out too far.. If you show the sheet I can tell you what shims to move and how many turns to give the tie rods..

The specs I gave above are for cars with the SC&C set up.. I'm not sure about your set up..

Does you set up add positive caster?

Does your car favor one side of the road or pull to one side?

Those are my alignment sheets shown in post 18 of this thread. And it doesn’t seem to pull to one side or the other. Just twitchy. It was better driving TO the alignment shop with what I eyeballed than after.

67_LS1 · Dec 15, 2019

Here are pics of my current shim stacks and tie rod ends. All photos taken standing in front of the car so in order passenger side, drivers side, passenger side, drivers side.

temp2c · Dec 16, 2019

If you have power steering. Get a box of assorted shims and put a 1/8" shim on both back bolts and tighten it up.. Looks like you could add a good three or four degrees yet and that's a good thing..

Since your car is worse after the alignment on the spread sheats, his rack must be screwed up because the numbers are perfect..

You should get more positive caster but it might toe out a little. Lets see how you like it after this first change.. We might have to do several changes.. Just tell me what happened.. We will take care of toe last..

Also, make sure the tire pressure is three pounds less then the maximum rating on the side of the tire. Check first thing in the morning with no sun shining on any of the tires..

67_LS1 · Dec 16, 2019

I do have power steering and even though I swapped the box for a later 12:1 ratio box it steers really light. Not sure if it’s lighter since the alignment or if it’s been that way since day one.
Thanks Jeff.
Sorry to hi-jack your thread Jim.

temp2c · Dec 16, 2019

The lightness of the steering is mainly in the box. I have a 14:1 Lee with a 30 pound valve and it's all the good things of a manual with all the good things of power.
It's there new 800 Series three bolt box. I used to think a heavy feel came from alignment until I tried this box. Most boxes are way over assisted. The new team at Lee has it down!! This new box is amazing!!

Dennis I don't think Jim minds since his problem was taken care of but if you want start a new thread. I will be happy to go through all this with you. I think its best to do this out in the forum so other can chime in with better ideas and questions..

67_LS1 · Dec 16, 2019

OK I added 1/8” shims to the rear of each side.
That makes the current shim stack as follows:

DF 1 -1/8”, 1- 1/16”, 2- 1/32”
DR 1- 1/8”, 2- 1/16”
PF 1- 1/16”,1- 1/32”
PR 2- 1/8”, 2- 1/16”

I hope to get my tires and rims back and on the car later today. I’ll report back how it handles shortly.

I feel like my power steering box already has higher effort than stock but not by as much as a 67 I had before?? Hard to tell because the other car I drive, my wife’s BMW X5, is SO stiff it makes anything else feel light.
Lee did my 67 box. If after more test drives I’m not happy I’ll have Lee take a look at this one too.

67_LS1 · Dec 28, 2019

I finally got my new wheels, put them on and was able to drive the car.

To recap, my alignment spec sheet is shown above (post #18) and to that I added 1/8” shims to the rear of each front upper control arm bolt as suggested by Jeff (Hydro462).

With the alignment as shown from the shop, the car felt really loose. All over the road Requiring constant corrections to stay straight.
With the added 1/8” shims it has REALLY calmed down. Like a different car.

At the same time I adjusted the steering box. I turned the adjustment screw on the top in 1/8 of a turn and tried it. It felt a little better. I adjusted it another 1/8 turn and it was better still. I’m not sure about going more. (Insert chicken noise here) As it sits now I have about 1” of back and forth (1/2” each direction) in the steering wheel before it starts to steer. Not as tight as my wife’s beemer but still pretty tight.

What it was recommended I do but haven’t yet is it to lower the air pressure down 3psi from the suggested. Problem is I don’t know what the suggested is. The tire says max of 60 in one spot, max 40 in another spot which both seem nut-zo high. The owners manual is useless because it shows 14” bias ply tires. Currently the tires are at 35psi front and rear.

So it’s way better. Steering effort is good. Tracking is good. Thanks Jeff.

I have no idea what toe-out is now. Should I take it back and have the toe checked or just keep an eye on tire wear?

pnugene · Dec 28, 2019

Dennis, the added rear shims probably made it toe out a little. Need to check it.

temp2c · Dec 28, 2019

Randy is right. The added rear shims toed out the wheels. But if they had too much toe in that actually helped..

I'd change the air pressure to 39 and see how that feels... Then we can try some more shims..

No sense going back to the alignment shop just yet..

Your welcome Dennis. It can be so frustrating getting these old cars to handle well and be fun to drive.. My view is if they are no fun to drive, no sense having them...

Jim Mac · Dec 28, 2019

dont know what kind of wheels your running, but when I swapped from the 15 inch ralleys to the welds it really made the front end feel more "lighter" for lack of a better term. going back to my original alignment sheet, is there anything i can do to add more caster to get it to feel a little less touchy driving? (alignment was done with the weld wheels). jim

should have mentioned the tire size is 275 60 15 rear and 207 70 15 front so it's got a slight rake to it which probably doesnt help, and I'm comparing the steering to my 66 which for some reason, after rebuilding the front end and rear end, new everything, then front sits higher than the rear. plus it's got manual steering where the 70 is power. jim

Alan F · Dec 28, 2019

When you change the offset in the front wheels you change the scrub radius on turning. Chassis engineers use scrub radius to create the feedback the driver feels through the steering wheel. As you can make some offsets in them, you should account for this when selecting your alignment specs. I try to never vary the offset from the factory front wheels because you tend to compromise your alignment specs.

A long long time ago I had a twin I-beam suspension and wreaked havoc on the ride and handling by installing larger offset wheels. Lesson learned.

temp2c · Dec 29, 2019

Alan is right. You want the wheels as close to the center of the car as possible.. Ever notice front wheel drive cars, they usually have no dish in the wheel including the 68 Toronado. When you put the front wheels "out there", it creates leverage against the steering linkage so when you hit a bump or curve in the road surface it feeds back to the driver as bump steer.. It makes the car feel jumpy, twitchy and does not inspire confidence...
Raking one of these old cars is one of the worst things you can do to them, it takes away positive caster. Frankly I never liked that look and prefer the 60s gasser stance that adds positive caster..

temp2c · Dec 29, 2019

Jim Mac said:
dont know what kind of wheels your running, but when I swapped from the 15 inch ralleys to the welds it really made the front end feel more "lighter" for lack of a better term. going back to my original alignment sheet, is there anything i can do to add more caster to get it to feel a little less touchy driving? (alignment was done with the weld wheels). jim

should have mentioned the tire size is 275 60 15 rear and 207 70 15 front so it's got a slight rake to it which probably doesnt help, and I'm comparing the steering to my 66 which for some reason, after rebuilding the front end and rear end, new everything, then front sits higher than the rear. plus it's got manual steering where the 70 is power. jim

Jim, take some photos of the shims in the upper control arms and post them.. Then we can see how much positive caster can be added... Maybe start a new thread unless the OP doesn't mind..

67_LS1 · Dec 29, 2019

I’ve always understood that mid 60’s Chevys liked zero offset wheels and that what I’ve always run. Back space is half the full width of the wheel, not the published wheel width.

Jim Mac · Dec 29, 2019

pics of the shims. thx. jim

temp2c · Jan 3, 2020

Jim, you can add a lot of positive caster yet. I would try two 1/8" shims on both sides and see what that's like..

Jim Mac · Jan 5, 2020

thanks jeff, add 2 shims on each side, so 4 shims about 1/4" . these go on the rear correct? and might effect the toe? jim

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