LCPLPunk

Hey guys,

So I'm trying to figure out if I'm seeing things, or if my rear tires are in fact bowed in ward. It seems like whenever I look at the car the bottom of the tires look more towards the car than the tops, and I'm pretty sure it's not supposed to be like that. I recently redid all the outer tie rods and got an alignment, but I'm wondering if there is something else I should do.

I saw this: http://www.ebay.com/itm/1984-1996-Co...BWlp1m&vxp=mtr

and was wondering if it might allow me to dial in some of the bow. I also thankfully have a lifetime alignment with Firestone, so I can go back and get it re-aligned for free.

Thanks!

antfarmer2

how are the tires wearing?

LCPLPunk

Not sure yet, they are really new with probably 1000 or less miles on them so far.

c4cruiser

Are the tires leaning inwards at the top as you look at them from the rear? Or leaning inwards at the front of the tire looking down from the top? Stock rear alignment specs for the C4 is 1/8" toe in (horizontally) and 0 degrees camber (vertically). With these specs, you really should not see anything that looks off.

Is there any indication that the camber rods or the toe rods are bent? They should all appear to be straight.

Did Firestone use these specs? Did you get a printout from their machine? Did they tell you they did a full 4-wheel alignment and didn't find any issues?

IMHO, Firestone would be the last place I would go for any sort of alignment work. Find a reputable shop with an alignment system that has recently been calibrated. And I would bet that the Firestone store would not honor their warranty if you replaced some parts with aftermarket stuff, especially if they said their alignment work was done according to spec and their employee did what he was supposed to do.

WVZR-1

I'd say that if you "THINK" you have an issue, you likely DO !

Take it back and show the shop what you believe the discrepancies are, give them an opportunity to explain, correct or what ever. If you weren't supplied a before/after print out ask if they have the capability to do so. Have them redo the alignment.

I don't think you can just say NO to Firestone in general. It's the equipment, the maintenance of it and the technician. The signage on the building is of little to no significance.

Forget about the product you linked to on eBay - you should have absolutely no need.

93Rubie

Here is a dumb question, did you get a print out from the last alignment? What is the specs if so?

antfarmer2

ask them to see the shims they have in stock for corvettes if they can not show you they just did a toe and go.

Silver96ce

Before you take it back in, get down and look at the camber adjustment arms bushings. The camber arms are the the two long arms that attach at each side of the bottom rear of the rear differential batwing. They control the adjustment to the tires with regard to tilt in/out (camber) of the wheel. I had the same problem and the bushings were worn out. If they are worn out, you'll have to replace them before a proper alignment can be done.

LCPLPunk

I did get a print out and I'll have to rummage around in my car to find it.

I'm pretty sure all my bushings are shot because the last two previous owners did very little (if any) maintenance with suspension outside of the shocks. I still need to redo all four ball joints in the front before it's somewhat close to being acceptable.

I don't like this Firestone because they charge an arm and a leg, but, they are about a 1/8th mile walk from my work so it's just too easy to drop off and get it back.

Oh, and the tires look like this \ \ / / - not that bad really, but you get the idea.

LCPLPunk

Ok, so here is the printout from Firestone, the before and after.

enventr

I would have taken it to an alignment specialist. You should have had a 4 wheel alignment. I too had a similar problem as I first bought my car to a franchise tire place "Mavis Tire" while living in NY. Shortly after the rear tires were similar to yours. I asked around for an alignment specialist that does corvettes as well as many other muscle cars and had the alignment redone. He said it was way off. He realigned it and it looks great. Firestone does not know what they are doing when it comes to corvettes. Ask around at a corvette club who they use. The place I went to does alignments and suspensions mostly. They also do brakes. That should fix your problem

aklim

Supposedly, all is right with the world. There is a minor issue though. Are you sure that the equipment is right? I asked a tech about doing an alignment on my car and he declined because there was a moron there who made a habit of dropping the heads often so even when it said the alignment was perfect, you can obviously see it is out.

The equipment is only as good as how calibrated it is. Keep dropping it after the rep has aligned it and your alignment might say good but it is way out.

antfarmer2

it was not right when they were done. I agree with droping or bouncing a few times the check to see if it holds when right.

LCPLPunk

What do you guys mean dropping or bouncing?

antfarmer2

in the factory they run it over a bunch of speed bumps to settle things. once it is set you want to bounce it around to see if it changes.

aklim

I'm talking about the alignment equipment being dropped and the calibration being knocked out

93Rubie

I am willing to bet $50 they NEVER touched the front end other than toe adjustment. Look at the before and after readings on the front camber and caster. No or little difference.

They set the rear camber and adjusted your toe angles that is ALL they did.
FYI, ANY alignment tech worth ANYTHING KNOWS that anything over .5 degree difference in caster side to side is BAD. Why didn't they correct that? If you paid for a 4 wheel alignment, you didn't get one.

Adjusting the front a-arms on C4's is NO harder than just about ANY GM car from the 50's thru the 80's. Movement of shims +/- is ALL that is required.

People that cannot do alignments correctly should NOT be in the business for working on cars in ANY capacity. They are NOT hard, you just have to actually DO a little work and do it accurately. They do it for speed so they can make more $$$. They usually paid an hour when I did them. I could do a true 4 wheel alignment in about 40 minutes including the test drive unless I ran into rusted stuff and had to get a torch. We charged extra for that as its not part of the normal alignment procedure but only the time it took to actually get the part/fastener loose.

You have some options:
Take it back and get another alignment check done and ask to get the caster fixed. Point out the more than .5 degree across the caster readings. Or take it to someone else and see what their equipment reads on the car.

93Rubie

This only needs to be done if the suspension becomes unloaded. Ex. You jack it up to make changes to the front a-arm shims on a C4. You can adjust the rear sitting on the slip plates. Or adjust only the toe up front.



Most modern alignment equipment does NOT require the car to be jacked up to do rollout compensation on the machine. Those that DO require this, yes, the car should be jounced to settle the suspension.

LCPLPunk

So none of my ball joints front/upper, front/lower are good, would this affect being able to get correct caster?

93Rubie

Correction, Firestone has a bunch of dumb employees who do not know how to do proper alignments on ANYTHING, not just Corvettes.

There is NOTHING special about the suspension on a C4 Corvette or any Corvette. Its not rocket science. You just have to understand what you are doing and read a little bit if you encounter a vehicle you are unfamiliar with.