02LS1Z28BC

iTrader: (4)

I have replaced both front lower control arm bushing sets. I took the car to Firestone (lifetime alignment purchased, they use a Hunter machine) for the alignment and after 4 hours of yanking/pulling/pushing/swearing/giving up for the day I get a (you have to maybe grind out the rear slot to get the rear ends of each LCA further out) result. The old three (one front and both rear) bushings measured exactly the same as the replacement 4 (moog) in the two kits. I measured all 4 of the new ones and old ones before removing/installing and made sure they matched the size and went in the LCA's exactly where the old ones were. Although I am almost positive there was space between all 4 bolts in the locations (two horozontal/two vertical), now the two rear vertical bolts are at extreme outer position (hence the suggestion they made that I grind the rear slots further out from vehicle center). I am pretty sure that will cause the bolts to hit the mounting point on top and I do not want to be grinding the bolt head any to fit it either.

I am extremely hesitant in altering the LCA mounting points, the only thing I did was replace both sets of bushings. The reason I replaced them is the left front one blew out the rear of the housing/mounting point. It was not out all the way (about 1 inch remained) and no apparent damage to either LCA is or was evident. While the car was being done, the guy had another guy come to help every now n then to get them (the LCA's) to co-operate and align. Throwing them together after working on them for almost 4 hours, they said try that setup. I went home with a hard right pulling, steering wheel to left of center, and a shimmy. The following morning (after looking over the service manuals set I have for anything I could have done wrong or missed, getting to bed after 3 am) I was back at 7 am when they opened, and spent another three hours having the car worked on. We started by taking a test drive. The guy reset both sides toe-in/toe-out and centered steering (as I said earlier they were way off). Another test drive showed the shimmy is still there, and unacceptable. The rear bolts are still all the way out (from center of vehicle) and I do not think he even touched either side front or rear LCA adjustment bolts/settings. What he did was check every other thing he could. Checked were ball joints (OK), tie-rods (tried to say LF was loose, after I showed him the RF was just as "loose" and the steering wheel moved lock-to-lock with the "loose" LF/RF tie-rods he agreed the tie-rods were ok), then he went wheel to wheel checking balancing and out of round (all four wheels/tires) and could not find a thing wrong (again, all OK). I am at a loss as I again took the car (the tech said he will call his partners in the local Chevy Dealership service department and call me) and parked it at home (I do not want to damage anything, nor get any scuffing/markings on tired which will divert from a diagnosis/fix after the inability of them to get it aligned within specifications and remove the "shimmy" it now has).

I will say the only thing different from the service manual set that I noticed, was the manual says to have the car suitably jacked up to set the camber/caster/toe. The Hunter rack they used (the tech says) does not work that way and it is unneccessary to have the front off the ground. BTW, the rear is well within specs, no off track alignment from the rear. No other modifications are on the vehicle except the replaced tranny and intake/exhaust mods, and a hyperteck power tune.

I was advised (by the local speed shop that installed my 750HP built up 4L65E and replacement torque arm bushing) to get it done somewhere else, to see if they can figure it out because it makes no sense to me or the tech at Firestone... any advice?

mitchntx

iTrader: (14)

I would ask when the last time they had the alignment machine calibrated.

But ...

The rear bolt has an attached "ear and tab" on the head. This tab goes in a keeper hole and keeps the bolt from spinning when tightened.

Are you sure the tab is in the keeper hole? If the tab is indexed and is hitting the inner fender or is hanging on the outer K-Member, it can reduce the amount of adjustment available.

It's almost impossible to see, but you can get your hand up in there from the bottom and you can feel the tab and you can feel the small hole it goes in.

The front LCA bolt has a similar tab and hole set up.

Cap'n Pete

iTrader: (2)

Could be tolerance differences in the construction the K-member.

When my car had the factory K-member (it has the UMI K-member now) I got about -1.5° camber on the right side, but could only get about ~ -0.5° on the left! The tech pointed out where the K-member was welded together, the plates where the slots are were physically ~1/4" further IN on the driver's side, hence why that A-arm couldn't be pushed out further to gain more negative camber.

Your car may have a similar issue. Just a little bit off in one place, and a little off in another, could add up to being off by a lot in total.

I'd go ahead and grind the slots out a little myself. Especially the rear mount (caster). This one never has a "pulling" force on it like the front (camber) mount does. Under normal accelerating and braking, the force always pushes in against the rear mount (unless you drive really fast in reverse ). I wouldn't grind away as much from the front (camber) slots due to that reason.

02LS1Z28BC

iTrader: (4)

Mitch, the "keepers" are all in from the moment I put them back in when I replaced the bushings. They came out of those holes, they went back in.

Cap, not sure when maching was calibrated, but the tech told me this machine even compensates for a car not on the rack squared. I would assume it has a "self calibrating" feature/function if it in fact compensates for the car not squared on the rack. Again, post bushing replacement the car aligned fine all values well within "the green" on the exact machine. The last time it was aligned was april this year, since I am the only driver I know no hard hits/potholes/bumps that would have damaged any component. If I was to grind the rear slot out further (not recommended) I would have a clearance problem with the "keeper/bolt head" as this is now up against the bracket/cradle at the outside of the slot where it is parked right now.

Thanks for trying though! Any other suggestions?

Cap'n Pete

iTrader: (2)

What are the alignment specs they've got your car at anyways? Do you remember the #'s? Did they give you a print-out?

02LS1Z28BC

iTrader: (4)

Capt,

The first visit (Friday the 21st August) all values were printed on the form (the set of three receipts/forms mysterousely dissapeared when I went looking for the keys, they were left on the counter and I did not pick them up when I left). The second set I made sure I have BUT a few of the values are not printed in but written in, so I do not trust them as written (may be right, maybe not, just am hesitant in things written in when capability was demonstrated that they were printed in before).

Front Left: Acutal Before Front Right: Actual Before
FL Camber = 0.5 (written in) 0.5 (green) FR Camber = 0.5 (written in) 0.4 (green)
FL Caster = 7.0 (red) 7.0 (red) FR Camber = 4.6 (green) 4.6 (green)
FL Toe = 0.02 (written) 0.37 (red) FR Toe = 0.01 (written) -0.49 (red)
FL SAI = nothing on line 13.6 deg FR SAI = nothing on line 14.0 deg
Incl Angle = 14.2 deg 14.2 deg Incl Angle = 14.3 deg 14.3 deg
Turning Angle Difference = blank all across
WheelBase = 102.1" nothing on line Wheelbase = 101.2" nothing on line
Body Wheel Offset = blank all across

Next table is below this table:
Actual Before
Cross Camber = nothing in line 0.2 deg (green)
Cross Caster = 2.5 (red) 2.5 deg (red)
Cross SAI = nothing on line -0.3 deg
Total Toe = nothing on line -0.13 deg (green)
Cross Turn Diff nothing on lines
Body Angle nothing on lines
Track Width(O.R.) = 69.8"

Do you need the rear specs only 3 of 10 showing as "Before" readings, no actuals...

Does this help?

02LS1Z28BC

iTrader: (4)

crap, it took me so long to put the damn spaces in to make it look good.... crap!

02LS1Z28BC

iTrader: (4)

dang if it doesn't look like my wheelbase is short one side or long other side, or a combination of both.....

mitchntx

iTrader: (14)

So let me make sure I understand ...

The left and right side caster bolts are at the far reaches of the slot (both away from the centerline of the car) and you are seeing +7.0 and +4.6 caster with nearly identical camber/toe settings?

And you haven't curbed a front wheel or hit a deep pot hole?

The left CAMBER bushing failed.

All ball joints are tight and its the correct bushing application.

At this point, I think I'm beginning to agree with your transmission friend. You either need a different tech yet again or preferrably, find another machine.

If the settings replicate yet again, then a knuckle, wheel or lower A-Arm is bent.

The wheel base difference could easily be a combination of factory tolerence and the different caster readings.

This is a head scratcher ...

02LS1Z28BC

iTrader: (4)

1, Yes, both to outer extreme of "slot"
2, No curb or pot holes hit brushed against.
3, left front bushing was more than half out the housing, about an inch remained (groaned bad like a rubber sqeak, thats why I looked with both front wheels off the car on jackstands)
3, yes and yes (looked/measured like remaining three intact but cracking rubber bushings)
4, On the differences of the wheelbase, I just noticed that, suspected maybe it was the result of the skewered FE alignment. I hadn't noticed it b4 until was asked about the readings on the sheet here today.

Head scratcher for sure, especially since the car was done last april with no shimmy, and all smooth as glass (as smooth as it could be being almost 8 years old or so). Also, did not have any pulling/shimmy/unusual ride except for the groaning rubber squeezing out of the lower front bushing before the replacement of the four bushings last week....

leadfoot4

iTrader: (1)

With that much difference in caster, as well as that much caster on the left, that thing must be doing LH u-turns like a "*****".......


Those Hunter machines are NOT self-calibrating, so it's entirely possible that the machine is out of whack.

99 6 speed

Firestone had the same issue with mine in a very similar end result. They even said that my left axle shaft was shorter than the right. They say my RF wheel is pushed back (which is visually correct, part of that work that needs to bo done), and the RR wheel is pushed out to the right and back tword the rear of car. This all leaves me contemplating fully adjustable LCA and PHB. Even consitered a tubular K member.

leadfoot4

iTrader: (1)

Two alignment "issues" are brought to light, and both occurred at a Firestone facility......

02LS1Z28BC

iTrader: (4)

Update, the tech contacted his buddy in the local Chevy dealership service department. Between the two of them, they want to move the entire engine (cradle) over then realign. I cannot believe these guys want to move the whole setup. All I did was change 4 bushings! Was going to go to another mech today but I found out they do not have a way of printing out a before/after summary (they do it the old fashion way with clamp on gauges/strings I guess). At this point, whatever I do, I want a before/after sheet to go back to firestone and get reimbursed for the inability of the tech to do the work. The new mech I was going to use, said the shimmy cannot be from alignment he says it is a wheel/tire problem, this is another reason why I am not going with him (they keep diverting away from the central fact the car was fine 14 days ago before the LCA's were removed for the bushing replacement.

Have to keep persuing this, good thing I have two backup vehicles, I sure do not want to "turn left like a *****", nor do I want this constant shimmying I have enough aches n pains in my joints..... hehehehehe

Anyone else out there care to dive in?


Footnote: Can anyone tell me whats needed/readings I need to get if I do what the service manual set says to do? In the section "Repair Instructions" under "Measuring Wheel Alignment", there are 4 steps to measuring them angles. Then the next section is "Front Caster and Camber Adjustment" where step 2 says to "Raise and support the vehicle". What is needed to accomplish this, I sure can't fekk it up any more than they have so far if its within my means to "do it myself"...

02LS1Z28BC

iTrader: (4)

Oh, btw, ledfoot, this Hunter machine I was told IS self calibrating. It is a new Hunter 12000 (well relatively new). I think I will look it up and see here on the "net"...

mitchntx

iTrader: (14)

The only thing that comes to mind about "Raise and support the vehicle" is when camber/caster adjustments are being made. Otherwise, when taking readings, the suspension should be loaded.

The engine cradle has alignment dowels to seat it in place. Not sure how it can be moved.

Cap'n Pete

iTrader: (2)

Exactly. There really isn't much room for "adjustment" of the k-member?! I think that's barking up the wrong tree.

leadfoot4

iTrader: (1)

I recently retired, and took a part time job delivering parts for a local auto parts store. I was at the local Midas muffler shop about 2 weeks ago, and a service tech was there working on their alignment rack. The rack is a Hunter "Hawk-Eye" unit, and while I was talking to him, he said he was "calibrating it", so I assumed that they all need some sort of setting up once in a while....

02LS1Z28BC

iTrader: (4)

OK, seems any place I go to wants to convince me that the shimmy is from a wheel being out of round or out of balance. The way I see it, the shimmy is coming from the wheels not rolling down the road parallel. Seems every place I went to wants to sell me another repair not related to what happened to my car. I still cannot get out of my mind the fact 14 days ago the car needed one bushing (rode as good as it got being 8ish years old), and I replaced all 4 since I was doing the one. Now (according to who you ask), wheels are out of round, unbalanced, the cradle is too far one way or the other, the slots for the camber/caster adjustments need elongating buy using a cutting tool, and the camber/caster bolts (with the keeper) needs grinding to allow it to slide more and not run into the mounting flanges (engine cradle/k member). I wish there was a way to do this on my concrete slab on jackstands, because I sure lost about all the confidence I can muster in the local alignment shops I visited in past 12 hours.

OK, giving some of them the benefit of the doubt, is it at all possible the wheels (front) are so out of alignment they are not parallel, and finding the ability to "skip" some (the shimmy I am feeling/seeing in the steering wheel)? The local service manager at the local Chevy dealership said the shimmy can not be from an alignment problem. He also was not ruling out the "entire crossmember shift to left or right" to get it able to be aligned. I might add, he did say he could not tell me for sure until he had it on the lift ($$$$$) and started working on it (again $$$$$). I don't know, I am trying to learn but a "pass the sniff test" feeling is creeping into my mind that there are just too many that want my car in their garage to generate revenue for their respective house or car payments under the guise of fixing a problem that I just cannot imagine has creeped into my car.

How many have been held hostage, those who have only the one vehicle? Who knows... Anyone know what I can use to set the alignment on jackstands? One of the recommended shops use the old fashion strings and dials clamped to various parts of the suspension. Is there a simple non electronic tech way to get this close enough to work, or accurate to drive daily? There are no aftermarket suspension parts on this car. All original in the suspension arena. Only thing (sounding like a broken record) is 4 new lower control arm bushings (from Moog at advance auto).

Anyone?

99 6 speed

I wonder if the bushings kinda settled in an incorrect setting (there by fixing it) so this is why it was smooth prior to the replacement. Just a thought. My '88 Bronco II was good for crap like that. Blew alot of money fixing all the rigged stuff on that, but I digress. Also, it can't be your K member being warped/chopped since it was fine 14 days go. I was going to suggeest the dealer. This is my next step for my car. They did a great job on my uncles 01(?) 2500. I belive he said it cost him $250 with the 4 wheel alignment and a flush and fill of the A/C system. I suggest finding a relatively new dealership. In Killeen the Chevy dealer has a much more up to date machine where the one in cove (15 min away) had a much older machine for a much older dealer. I know it will be pricey but I have to do something and I've read too many horror stories on here like this where no place could get it right and kept draining money. It doesn't help my case that I know my K member is out of alignment.