Attached is the printout from the alignment check.

 

I have driven another C7 Z51 non Magnetic ride and it is smooth and exhibited none of the symptoms I am experiencing.

 

I'm no expert at this stuff, but if this was my car, here's what I'd do:

1) I'd get the rest of the alignment values identified. Caster should be even on both sides at around +7.5 degrees (maybe a slight difference, side to side, to account for the crown in the average road). And your front camber is further off, side to side, than I would accept -- for average street driving it should be around -0.7 degrees on both sides (no more than 0.1 degree difference from side to side). Could be further negative by a couple of "tenths" for more aggressive driving, or a couple of "tenths less negative for straight highway driving. Rear camber should probably be about 0.2 or 0.3 degrees less negative than the front settings. Toe in should be about 0.05 degrees on each corner. You also need to check the rear "thrust angle" -- it should be as close to zero as possible.

2) I'd give this car a serious "physical exam" -- or get a qualified mechanic to do it for you. It's a new car so the dealer should be willing to go over things for you. Get it up on a rack and check all the suspension components for integrity and fastener tightness. You could have a broken sway bar end link, loose shock mount bolts or who knows what.

I hope you find the issue and get it fixed so you can get on with enjoying your new Vette. Good luck with it.

 

Appointment scheduled next Tuesday with the dealer to get the car on an alignment rack and go over all the measurements and also go over all the suspension parts again. This is driving me nuts. No car should exhibit what I am feeling in the rear. Hopefully we find the culprit and get it fixed and I can feel safer going through some twisties in the future.

 

 

If nothing is found with the checks done next Tuesday, I'd ask that they pursue the suggestions made earlier by xp800:

 

How about undoing the lowering.

 

Can't see that as the problem. I would wager there are many here who have lowered their C7's without one bit of a problem. But if the dealer's alignment check and suspension review elicits nothing then perhaps I will entertain raising the car back up. But I am still convinced that is not the problem.

 

Agreed... no way this has an impact. Someone, somewhere would have also reported this given many C7s are lowered. Mine is and it has been used as a DD and at the track and zero issues. This could be a bad shock... who knows.

 

http://forums.corvetteforum.com/c7-g...-came-off.html

May want to look at this thread, looks like the OP had similar handling concerns before something in the rear failed.

 

Ouch. Will hopefully find out tomorrow when on the rack.

 

If you read through that post he had an earlier post of the rear end darting around when hitting a big bump a couple days before it failed.

http://forums.corvetteforum.com/c7-g...-question.html

Looks like you guys both use the same dealer, if it were me I'd have someone look at the rear suspension hardware and make sure everything is tight ans in place before driving it much.

Not trying to be an alarmist, just hate for you to have a problem on the road.

 

OP, did you do the lowering or did a tech do it for you?

The reason I ask is that is there a possibility that the adjustment bolts weren't raised (corner lowered) evenly? If they were done unevenly, the corner weights may have changed the balance enough to cause odd behavior.

When I lowered mine on the stock bolts, I used a paint pen to mark the original zero. I backed out each bolt 3 turns exactly. This was not the max possible, but at least I knew they were even.

I never measured corner weights on mine before or after, and I'm not sure a spec is out there. Just trying to throw more ideas out there to check when you have a tech's attention.

 

I did the lowering. Everything was measured before and after on height and turns were even left and right.

 

If the alignment and pressures check out...it all boils down to the suspension on the cars. The C5 did it, the C6's do it...and so do the C7's. Primarily it is a function of the leaf spring from what I could tell. When going to a coil over on any of the cars, it generally stops that completely.

 

Jim, what was the outcome of your dealer visit this past Tueday? Anything peculiar discovered?

 

The appointment was cancelled and needs to be rescheduled. They have to buy the Digital Angle Gauge and Adaptor to measure the rear caster. You would think that since GM has designed a caster adjustment into the rear suspension that they would require the dealers to purchase the measurement tool. But what do I know?? I am still waiting for a call from their Service Manager to schedule another appointment. Hopefully soon since I am averse to driving the beauty until something is found. Thanks for asking.

 

There is only one single part that can do this and no one has mentioned it. Mind boggling.

 

Care to elaborate?