Mark A. Rogalski

iTrader: (1)

Hi All,

This forum has been a primary reason why I've kept this '98 WS6 Vert for nearly 20 years. However, because I can't solve this suspension problem I drive the car less than 2k miles a year. So....with much gratitude I am back at LS1Tech for some help...again?

ISSUES (Could be related):
1) The outer edges of both front tires wear down to the cords after 6k-10k miles with casual non aggressive driving. I'm tired of turning corners like a grandma to save the edges of the tires. I don't race or autocross.
2) The car goes straight down the road but there is medium steering vibration from 46-50MPH. Headscratcher - if the roads are wet, the vibration at this speed is violent, shakes the entire front end, can even see the hood moving.


ISSUES STARTED AFTER CURB JUMP (ACCIDENT):
To avoid an accident in 2005, I yanked the wheel to the left and jumped a high curb of a divided median. Most all of the impact force was on the passenger side frt wheel. Bent the lower control arm, upper control arm, outer tie rod end, and flat tire on that side.

I took it to a large Goodwrench Carstar Body Shop around the corner from a Pontiac GMC dealer.

PARTS REPLACED FROM ACCIDENT
Instead of battling forever with insurance co., I had the body shop replace front suspension on both sides.
L&R Upper and Lower Control arms - GM parts
L&R Steering Knuckles - GM parts
1 Wheel Hub - Pass. Side Only (They messed up) - GM
L&R Upper Shock Insulators/Mounts - GM
L&R Sway bar end links - GM
Replaced both front Eradispeed Rotors with new ones (& new pads)
Koni yellow adjustable shocks (All 4 corners)
SLP Springs, all four (For the Firehawk - I think?) Car Was Lowered About 1.25"
All four HRE wheels were refurbished by manufacturer to fix any runout or damage
4 new Michelin Pilot Sports, Road Force balanced

Notice new control arm bolt locations after suspension replacement.


SPACER INSTALLED:
Even with new springs, the car sat noticeably low in the front right after accident. I installed this one spacer under the new Koni strut.


TROUBLESHOOTING - RESULTS:
1) Car pulled left after suspension replacement. Took to Chevy dealer who specializes in vettes, car goes straight down the road. They are good.
2) Clicking noise when turning steering wheel - The 3rd shop I tried found rack bolts were loose, said probably caused by the accident.
3) The frame has been checked 3 times, by 2 different vendors. They both say it is within spec, can't be causing tire issue, or cause of why passenger frt side is lower to ground (spacer then installed).
4) Alignment has been checked by several quality shops. None have a solution to the odd outer tire wear or vibration. The car drives straight down the road.

In 2014 I had the wheels checked again, then road forced balanced 4 new Pilot Sports.
At nearly $800 per pair tires, I need to figure this tire wear issue out.



A few years back a Mustang pulls next to me at a stop light. Rolls down his window and says "Better look into some new front tires their guy". That just fried my ***, tires had less then 10k miles. Rotating them to the rear makes things worse. I wind up with 4 nasty looking rounded edge tires.

JD_AMG

After all this did you ever get the shop to print what the actual alignment is at? If not that is the first thing you need to do to tackle the easy low hanging fruit before tearing anything apart. Many shops will get the car "within spec" but that doesn't mean squat as my car was "within spec" when it was stock and eating the outside front tires as well (not as quick as yours is though). So I take it to a place a friend worked at and told him exactly what to set it at and watched him do it on the machine. Tires have even wear ever since then.
I did -1 camber, as much caster as possible (i think it ended up being around 5 to 5.5), 0 toe, you can run some toe out though.
The before specs were something along the lines of 0 camber and a little toe out, the 0 camber was killing me as the tires were rolling over in turns causing the outer edge to wear, but it was all "within spec" still. Hell if I remember right a little positive camber is still within spec, which is definitely not what you want.

Mark A. Rogalski

iTrader: (1)

Thanks so much JD,

The Goodwrench body shop in 2005 used the Pontiac service dept for alignments, who couldn't get it to drive straigh. They sent me to the Chevy dealer. This sheet is from 2005, just not sure who - someone has covered the names.

Several thousand miles later is when I noticed the massive outer tire wear.

farmington

iTrader: (14)

I get all of my alignments done at an old school frame shop. Never had an issue with their work.

ChrisSingh90

iTrader: (12)

If the front right sat noticeable lower than the front left, even after new springs, I would assume that the strut tower bent upwards from the impact.

Floorman279

iTrader: (11)

Im kinda thinking somethimg similar, but i wonder if the bubble are where the 4 shock mount bolts go didnt get raised or pushed up. Not sure if thats where u call shock tower. Take a glamce all around the underhood area and look for any signs of like spiderwebbing paint on the unibody. Sometimes if its bad enough u will see faint lines.

Mark A. Rogalski

iTrader: (1)

Thanks All. Look how chewed up the outer edges of these brand new tires are (click image to expand).



If I wanted the opposite, the inside edge of the tire to wear out, what adjustment/setting would I tell an alignment shop? (If I'm gonna waste tires like this, I rather not see it, might have a shop purposely reverse the issue.)

So I put a couple hundred miles on in last 2 days. At any speed, applying brake, I get front end wobble. When I hit bumps, front end wobbles a bit. Never did this before accident. Something is definitely loose with the front suspension. I could probably start over, R&R all control arms, just getting burned out with this car. I will NOT buy all new control arms but I could buy all new bushings - have a shop press them in. Since I have all the shop manuals I can reinstall arms and torque to spec myself.

Brake shimmy.
I'm assuming its the Baer Eradispeed rotors causing this again, my 2nd set. The first set shimmied too after 10k miles. Back then Baeir said their rotors don't warp. So I called their HQ here in Phx. Said bring um down for testing. Said mine were fine, probably dust build up, blah blah. I bought a new front set and the braking shimmy disappeared. I will not buy a 3rd set. Will get these turned. EBC Brakes states turning slotted/drilled rotors, find a shop with a lathe from Pro Cut, and their Rotor Matching System.

What a nightmare piece of crap car, never ends. The very violent front end wobble at 47-50MPH when roads are WET still has my head spinning.

SparkyJJO

iTrader: (11)

First off - aim for a little more negative camber. The image has some corruption on it so I can't see exact, but it looks like you're pretty close to 0 camber. With those wider tires try aiming for a -1 camber like JD did. Positive camber will kill the outer edge of your tires, particularly the wider you go.

Sometimes scrubbing of tire edges can be caused by toe in or out, and can cause some really weird shimmy when wet, but your toe numbers look fine.

The passenger front being that much lower just seems wrong though. A tad bit I can see given how the passenger side is always a little lower than driver side on these cars, but if it became noticeable after the accident and needs a spacer to attempt to even it out that just seems like an issue.

ChrisSingh90

iTrader: (12)

If both outer edges of the tires are wearing, that's also pretty indicative of toe-in, or negative toe.

When was the last time you got an alignment? Honestly I'd say take it somewhere new and see what their machines say when they hook it up.

The information being blurred on that alignment sheet you provided is a little suspect...isn't that the area where the car information is displayed? Maybe they couldn't get it within spec and sent you someone elses alignment sheet and blurred their information off the top.

Maybe it's time you do an old school string alignment, you can do it yourself. Check these video. .

With the string, you will be able to clearly see if the front wheels are toe'd in like I think they are to cut the tires like that.

Chris

ramairetransam

iTrader: (18)

If it was me just trying to spend the least amount of money i would find a reputable shop do an alignment on it . Next i would look into getting it on a frame machine .
Trust anyone at any shops that you could drop it off and tell them to go over the front end for any loose or warn parts?

Next i would wonder if the k member is bent or its mounting points moved a little .

That tire issue looks like an alignment issue.

Mark A. Rogalski

iTrader: (1)

Guys It's not abgout another alignment. I have had numerous alignments done, now 5 different shops, they find nothing of significance wrong. The car drives straight down the road. 3 of them also checked the frame. There is something else wrong - something they can't find in a static environment. Something must be loose, somethin moving under braking, bumps, and possible moving when turning.

Think on this - The car shimmies at 47-50MPH and when the road is wet, this turns into a violent shake? Wet road no longer allow the tires the grip needed to keep the front end stable. What could this mean?

When I hit a bump the front end wobbles and sometimes the steering wheel shimmies with it - while the dash stays stable. This means movement is traveling up the rack and into the steering wheel. I Suspect this has to be the k member moving.

Chris, thanks. That alignment sheet was created by me, scanning the paper original, uploaded in 2005. Someone on LSiTech or other added that masking back in 2005 to hide a competitor.

JD_AMG

I agree that the alignment is probably not the sole problem, however where you are at is not helping the issue. It doesn't matter how many shops have looked at it if they are all setting it to "stock spec" if the stock spec = outside tire wear most often. Go to a place and have them set the camber to -1.0, and the toe to 0.

SparkyJJO

iTrader: (11)

What width tires are those?

Since you're also saying something must be loose: Go jack up the front end, and inspect every single bushing, joint, nut, and bolt to be sure there is nothing loose. UCA bolts, LCA bolts, upper strut mount nuts and bolts, inner and outer tie rod ends, bushings, etc. Heck, you just said yourself that you suspect the K member is moving, so go crawl under there and look at it!

That is the only way to verify you don't have something loose.

Go from there.


Point on the alignment comments are all the shop are putting it at factory specs which call for 0 or even a little positive camber, which can result in what you're seeing (riding the outer edges of the tires) particularly when you're on wider tires than factory.

And when you're riding on the edges of the tires your traction is also going to be negatively impacted, so when you have lower traction situations such as wet roads you could be then riding on the edge of hydroplaning the front tires, resulting in a shimmy feeling as they lose and regain what grip they do have.

Not saying that this is 100% certain the issue, but it seems suspect. And JD already said that fixed a similar tire wear issue he had, so it isn't just hearsay but first hand experience on his part.

Here's something I've learned - when trying to track down a weird problem, you never rule anything out just because "it was done already." Something is wrong, so go back over everything, leave no stone unturned.

Mark A. Rogalski

iTrader: (1)

Now that I think this through - loose K member??

After the accident one header was dented. I took it to a highly reputable vette shop in Phoenix and had both sides replaced, also had them install and new Z06 clutch, flywheel, plate, hydraulics. I had vibrations the minute I picked up the car. Just to get me out the door they said new motor mounts were needed. So I took it to Pontiac dealer. The actual mechanic approached me and said he "ground off the tabs on the new mounts" I pretty sure he also said he "raised the engine and lowered the cradle....blah blah" in order to get the mounts installed.

My point - maybe the Pontiac technician left the k member loose. I did talk to their service manager why they would modify a part to make it fit, instead of getting the right part. He checked, the mounts were supposedly the right part, Nothing was done.

Back then I came to the forum and found out the flywheel needed to be balanced. I approached the vette shop and they did not match the balance to the old flywheel. In fact, they never sent out the new flywheel for balance either - just slapped it in and through out my old flywheel like and old rag. I was screwed again.

You guys get the picture of why I hate dealing with this car? No matter where I go, I can't seem to find competence.

SparkyJJO

iTrader: (11)

I'll buy it for tree fiddy then

ChrisSingh90

iTrader: (12)

Most places won't mess with the flywheel if it looks good, honestly there's no need to IMO. Yes in an ideal world you will have the two balanced, but most of the time it's fine.

I think the first order of attack is finding someone local, maybe from the forums, that will help you go over the entire front end. There's been way too many hands in the pot, so we have no idea what's going on with your car. Between things that could have been messed up from the accident, things overlooked by local mechanics, and things done incorrectly/messed up by local mechanics, there's too many possibilities. Time to establish a new baseline.

It sounds like you are the type of guy that doesn't mind shelling out the cash to get things done the right way, getting quality work seems to be the problem. I completely understand your frustrations.

From my experience you need to find a very well renowned shop, like one of the sponsors on here, or just do everything yourself. Like stated before, you need to begin rechecking everything, and that includes getting it realigned or checking it with a string like I mentioned.

Chris

leadfoot4

iTrader: (1)

Just my $0.02 worth.....


If you need a spacer, on one side of the car, to "level it out", and you didn't before, then either the k-member is bent, or the shock tower is bent.

While your alignment, based on the print out, isn't "bad", it isn't great. Contrary to what was previously posted here, toe settings, as shown on the read-out sheets, is always assumed to be "toe-in", therefore a toe setting that shows a "positive" number, is indicating "toe-in". Your toe settings are symmetrical, which is good, but they're showing considerable "toe-out". For example, I used to run at 0.02* toe-in, but you're sheet shows 0.06* toe-OUT. That's a pretty big difference.

Keep in mind, cars are normally set up with a little toe-in, to compensate for rolling resistance, so when the car is actually in motion, the wheels are actually pointing straight. Rolling resistance increases with tire width, so if you're starting with toe-out in a static position, it's increasing as you're driving. Also, you didn't mention tire pressures....did you?

BUT, if you're noticing "shaking", something has to be "loose". Your parts list includes just about anything/everything that could have been damaged, so there shouldn't be anything there. However, a thought just occurred to me...how's the driveshaft? Was it damaged in the crash?? Since you appear to have a lot of stuff looked over, maybe it might be worth having that looked at, too......

Good luck!

00PewterSS

iTrader: (3)

I think everyone here would like to help you out, but it is extremely difficult to do so.

Just sharing personal experience. I had a vehicle wearing the rear tires out and it was due to a bad front ball joint... I wasn't looking on that end of the car! My point is you could have an issue with the rear not tracking the front. Look at your thrust angle... it is a very small number, but it is out of spec. If you hit something so hard you somehow bent a header I have no idea what else could have been tweaked.