Front Alignment-Puzzled

Got the vette aligned today on a laser machine. I have a vbp performance plus setup with a grand am rack. To get the Front caster/camber in the acceptable range we had to take all the shims out of the upper control arm bolt on the firewall side and add 1/2" of shims to the upper control arm bolt on the radiator side. We did this on both sides. The car reads perfect now and tracks just fine. The toe in/out is perfect as well. I am just puzzled at the 1/2" of shims on one bolt.

What specs did you align to?

Whatever the stock 1976 corvette specs are. I watched him click on the tabs on the computer to bring up the specs

Doesn't that suspension set up come with offset upper control arms? If so that is what is going on. The offset arms are designed with additional positive caster built in. Caster should be around 4.5* with offset arms. Stock is around 2.5*.

Didnt know that! Should it be alright aligned to stock? I will get it adjusted when I get a chance, but I have quite a bit of driving to do until then.

I don't see how it would hurt anything. You just won't get the full benefit of the system. When convenient would would have it realigned to these specs depending on your driving style.

http://www.vbandp.com/instructions/htmlinstruct/align.htm

Thanks for the link! What will be my best bet? Just take some alignment shop those specs? Will they know what the heck to do with them? Lord I guess I need to buy an alignment machine ..Gotta do everything your friggin self

BlackBetty said:

Thanks for the link! What will be my best bet? Just take some alignment shop those specs? Will they know what the heck to do with them? Lord I guess I need to buy an alignment machine ..Gotta do everything your friggin self

Click to expand...

Well, you don't HAVE to buy a alignment machine, but you CAN DIY, I have been fine with my home alignment for some 5? years now.....
tire wear is good and even....car handles nice,

:bounce:

If you are happy with the work the last alignment guy did, take it back to him. Just give him the specs you want him to set it to. No problem. The colors may show red, out of design spec, but that doesn't matter. Just so the final adjustment specs match the specs you give him.

mrvette said:

BlackBetty said:

Thanks for the link! What will be my best bet? Just take some alignment shop those specs? Will they know what the heck to do with them? Lord I guess I need to buy an alignment machine ..Gotta do everything your friggin self

Click to expand...

Well, you don't HAVE to buy a alignment machine, but you CAN DIY, I have been fine with my home alignment for some 5? years now.....
tire wear is good and even....car handles nice,

:bounce:

Click to expand...

Hey Mr Vette,

Please direct me to other threads about DIY alignment. I am doing a search and this is the first one I ran across. Took car in today, they called in a panic that my whole car was screwed up, someone had been messing with it or it had been wrecked, that it was bad. I asked how much $ are we going to get into to fix it, well, they didn't really know. Car is back home. This is after they all commented on the low front end how cool it was, flippin idiots.

I've cut one coil out of front springs, so I know there will be some shimming. Assuming some fishing line and a couple of levels?

thanks

tt

OK, if you have a chassis/frame manual you can tell in a heartbeat what is with your frame, but you have to get it in the air, and take some measurements...the main one is to make sure it's square...so pick some symetrical points on the frame....say the lower front A arm forward pivot....or a frame junction point....measure to say the opposite side of the cross support, or even the rear suspension where the T arms pockets are....should be damn close, within 1/4 inch I THINK.....TT would know....

IF the frame is straight and the seams look clean and un bent it's fine....

you can find the various heights off your shop manual for your year....I have one for my '72, but that maybe not good for you....

also measure the wheel centers to centers on both sides....+- 1/2 inch is ok too, as I RECALL.....

www.vettenet.org/align.html


www.vtr.org/maintain then go find diy/alignment.html.....

I have had these printed for some years now, and are my ref points to do home alignment....

you have to plumb up your concrete shop floor, using a good carpenter's lever, and some steel lengths I happened to have around, side to side is critical on each end for camber, for CASTER in front the back ass has to be level and plumb with the front....

I use floor jacks with a monofil fishing line strung stiff between them....MY shark is 3/8 wider in rear than front so set the string 3/8 closer to the center hub of the wheel, then the front, then use a steel tape to set the toe.....I use some plywood with shims for leveling the floor out, formica on the front end, some grease, and a flat beer carton under the front end....

I can easily spin those front tires from one way to the other with one hand....they are that easy to flip.... so you know the measure on the tape from rim to rin front/back is right....set the rears the same technique...PIA on a C3 with them shims...but newer vettes are EASY...

last alignment on my car was done about early 03, on my second set of tires now, and they wore fine, still do....

the tables in the VTR site take all that trig outta the stuff, just look it up....

I used a metal carp level with screws and shims in the edge to hold against the tire bead, just like it was a alignment machine....

up north for years, I had freinds in the alignment business....so no sweat...here now, no one competent....so DIY or DIE....:suicide:

Your tha man. Thanks so much for all the info. Guess I have something to do this weekend , besides cut grass etc.

I'll keep you updated on how it goes. Dang, I've done everything else to this car all the body work, paint, electrical, engine rebuild, transmission, what the heck, might as well do the alignment too. All thanks to help from you guys!

thanks again!

tt

Update

Hey guys,

Just a quick update. Friend and I finally found some time to adjust out the alignment on the 82. For some reason, during the past life, the steering wheel was out 90 degrees. The biggest thing about this was not being able to see the gauges, especially the speed. We wound up cranking the tie rods out on one side and in on the other and with maybe 5 total turns the steering came back to center. Initial drive testing showed very good with a slight pull to right.

Although the shop did not want to do this car, I did get the initial specs which gives me an idea of what I have. Everything was in spec as is except the caster which is left 4.3 right 3.1. From all I have read on caster the car should pull to the left? Is it worth time to adjust out 1 degree of caster?

We did make one more adjustment on the toe and not yet driven so pull to right may be ok now.

I am assuming that the caster changed due to lowering the car?

The articles suggested were great and made this a lot easier. I was not going for perfection yet, but have a couple of jigs in mind that will make things even faster to make further adjustments.

Thanks for all the help!!!!

tt

Caster is the hardest thing to adjust, as the rear of the car has to be plumb/square to the front also....as well as side to side so the frame is loaded correctly/evenly.....that a way you can get your caster pretty damn close....

1/4 turn on tht wheel is a LOT to be just tie rod ends....you sure your dots on the shaft/wheel line up ok?? easy check is your turn signals...they cancell the same wether turning R or L??? if not, your wheel is off on the shaft, and so to check that first...that cancelling should be identical in wheel rotation, right to left...if not...get that steering wheel on there clocked correctly...then go for the wheels/tie rods....

:beer:

Good call! I checked the wheel, rag joint, shaft to steering box, twice. Everything was as should be. Apparently, in the past someone had steering in wrong position when doing an alignment??? (It is amazing what you find in these old cars, I unloaded two 5-gal buckets of speaker wire from under the carpet and seats) Now that you mention it, previously, left turn would cancel, right turn would not, or vis a versa. We adjusted everything to the right. Hopefully both will cancel out now.
I'll check it asap if it every quits raining. Thinking about building a boat! Guess you guys may be rained out now, we got an inch this a.m. (South of Bham), and I think 47 inches so far this year. I think our yearly average is less than 47 inches. :crap:

Thanks for the help!
tt

gr8vet said:

Hey guys,

Just a quick update. Friend and I finally found some time to adjust out the alignment on the 82. For some reason, during the past life, the steering wheel was out 90 degrees. The biggest thing about this was not being able to see the gauges, especially the speed. We wound up cranking the tie rods out on one side and in on the other and with maybe 5 total turns the steering came back to center. Initial drive testing showed very good with a slight pull to right.

Although the shop did not want to do this car, I did get the initial specs which gives me an idea of what I have. Everything was in spec as is except the caster which is left 4.3 right 3.1. From all I have read on caster the car should pull to the left? Is it worth time to adjust out 1 degree of caster?

We did make one more adjustment on the toe and not yet driven so pull to right may be ok now.

I am assuming that the caster changed due to lowering the car?

The articles suggested were great and made this a lot easier. I was not going for perfection yet, but have a couple of jigs in mind that will make things even faster to make further adjustments.

Thanks for all the help!!!!

tt

Click to expand...

The caster is causing your slight pull. The car will tend to drift to the side with the least amount of positive caster. That is your right side. Generally you want caster to be within 1/2* of each other and the most positive number on the right. That helps with the slight right drift you can get from the crown in the road. I'd set the right side to the most positive caster you can get and drop the left side back to match.

Sky65 said:

gr8vet said:

Hey guys,

Just a quick update. Friend and I finally found some time to adjust out the alignment on the 82. For some reason, during the past life, the steering wheel was out 90 degrees. The biggest thing about this was not being able to see the gauges, especially the speed. We wound up cranking the tie rods out on one side and in on the other and with maybe 5 total turns the steering came back to center. Initial drive testing showed very good with a slight pull to right.

Although the shop did not want to do this car, I did get the initial specs which gives me an idea of what I have. Everything was in spec as is except the caster which is left 4.3 right 3.1. From all I have read on caster the car should pull to the left? Is it worth time to adjust out 1 degree of caster?

We did make one more adjustment on the toe and not yet driven so pull to right may be ok now.

I am assuming that the caster changed due to lowering the car?

The articles suggested were great and made this a lot easier. I was not going for perfection yet, but have a couple of jigs in mind that will make things even faster to make further adjustments.

Thanks for all the help!!!!

tt

Click to expand...

The caster is causing your slight pull. The car will tend to drift to the side with the least amount of positive caster. That is your right side. Generally you want caster to be within 1/2* of each other and the most positive number on the right. That helps with the slight right drift you can get from the crown in the road. I'd set the right side to the most positive caster you can get and drop the left side back to match.

Click to expand...

I agree, I think, have to go back and read again to be sure....:search:

but on that steering wheel, that turn signal cancel/rotation feely thing is your key to wether you need pull that thing apart...that wheek hub sets on a spline on the column shaft, and if that is off a notch or two, the wheel sets cocked, while the turn signal cancelling cam is down forward of that spline, so it's off center, and your dots stamped into the hub and the shaft don't line up...if not DOTS specifically, hash marks....it varies .....but that right there is the giveaway so jack the front end and see what that turn signal does on the cancel return on wheel rotation....THEN you can adjust your tie rods.....if someone just tossed it all together, there is no telling WTF you got....hope it's simple, you MAY have a bunch of compounded errors, but the thing up at the wheel/turn signal has to be kosher first, and everyone further down has to line up to agree.....

:shocking::banghead:

I had to adjust my steering wheel the same as you by adjusting the tie rod ends. If your turn signal cancel cam is worn (like I believe mine to be), there's another way to confirm your steering wheel is centered. Just get the tires pointing straight ahead and count the turns from center to full lock right, then do the same to the left. Should be the same. Or count from full lock left to full lock right, then go back half way and see if the wheel is centered.

I recommend you get copies of Jim Shea's steering papers. There is some very good info in at least one of them regarding centering the steering wheel, column etc.

DC

Hey Tyler, I'm just all over your thread, sorry dude......

Finally getting a chance to get into adjusting the caster. From all the stuff I have read, and my eyes are bleeding! I need to get 1 degree more positive on the passenger side. (as noted from the alignment shop) I still have a slight pull to right.

Assuming I, loosen the bottom two bolts on the a-arm and bump it forward. About how far? Being I do not have any kewl measuring devices except some levels and cheap degree wheels.

I know that are jigs and other things I could do but I have run out of time as I am leaving for Hot Rod Tour tomorrow.

Thanks in advance.

tt

To increase positive castor you need to add shims to the front bolt or remove shims from the rear bolt on the upper a-arm on the side you want to change.