mitchntx

iTrader: (14)

To rule out a bent o out of round rim, rotate your tires.

Not sure where you live, but if its anywhere close to Granbury, Tx. you can use my turn plates and Longacre alignment tools.

02LS1Z28BC

iTrader: (4)

OK, am I having a sort of epiphany here? If the rear settings are pushed way out to its limits (away from center of vehicle) isn't that an increase in positive caster? That is the exact condition I have. The tech said on the first day (4 hour rack time) that the hole needed to be elongated further out. If positive caster is a rearward tilt of the wheel on its axis, then the damn thing is already too far out with a positive caster.

Think carefully, I think it may be THIS FEKKIN SIMPLE? Take the caster settings CLOSER to vehicle center!

02LS1Z28BC

iTrader: (4)

Mitch, thanks for the offer, being in central South Carolina it would be quite a drive. Thanks again!

please help me verify my number 22 above?

Is the rear vertical bolt the caster setting bolt, and wouldn't pulling the setting inward reduce positive caster to a lower setting?

mitchntx

iTrader: (14)

Not a problem at all.

Yes, you should be able to take the +7* caster down to +4.6*.

But for the life of me why wouldn't the tech make them match if they are within range?

02LS1Z28BC

iTrader: (4)

The tech must be an idiot. He kept saying the slot for the caster was not far out of center enough to reduce the positive caster. It took me days of help here and reading to stimulate the #22 entry above. The tech (used loosely) must have gotten his directions reversed. I sure as hell am going first thing in the am back to them and have someone else do the alignment. Plus, I am going to make sure they know I am EXTREMELY not happy I have had to go through this crap with all that has happened to me in the past 7 weeks.

If this is all that has been wrong, I am both glad I did not have to cough up $, but am happy my ride will be back on the road tearing up the streets where I ride

Jeeze.....

BTW, it was the book I bought (thinking) it was a service manual set (chiltons) page 10-17, that got me thinking about the reversal and the fact bringing the LCA caster end back towards center would tolt the wheel center towards the front of the vehicle (therby reducing positive caster).

mitchntx

iTrader: (14)

When I asked this ...

I thought you were wanting for +7* on both sides.

But if you are looking for ANYTHING as long as it's even on both sides, that should be easily done.

xXSilencerXx

iTrader: (4)

Good luck man, I lowered my car and got new A-arms. Needless to say I'm going back a fourth time to get it fixed again. Guys just don't know what they are doing.

02LS1Z28BC

iTrader: (4)

Noooooooooo, I want the settings stock, and as close to center (optimum) as it can get

Anyone else verify moving the rear setting closer to center of vehicle will lower positive caster?

Much appreciate some input

02LS1Z28BC

iTrader: (4)

Bump!

Will moving the rear (vertical) settings on the front lower control arms (LCA's) TOWARDS vehicle centerline lower positive caster?

Need input before jumping on Firestone's ***.

Thank you!

leadfoot4

iTrader: (1)

"Lower" the caster may not be the correct term. "Reduce" would be more appropriate, however I know that it's sort of splitting hairs.

Nonetheless, for the sake of definition:

*Sliding the front of the lca toward the center of the car "increases" positive camber, sliding it out "increases" negative camber.


*Pivoting the rear of the lca toward the center of the car "decreases" caster, while pivoting the rear of the lca outward "increases" caster. (while I'm not 100% sure, I doubt that there's enough range of movement to allow you to go so far inward that you go "negative" on the caster setting)

Getting the caster/camber set properly is a balancing act between the positions of the front and rear of the lca, with respect to each other. If you have access to the "U" shaped tool that is recommended in the shop manual, it makes the job a LOT easier.

Hope this helps!

Cap'n Pete

iTrader: (2)

Short answer, YES .

Typically, you would want both sides maxed OUT for caster, but in your case, having the big split from the driver's side to the passenger's side, then obviously you want to reduce the amount of caster on the high side, to balance it out. That should NOT be a problem for the garage to accomplish!?!

Hope you can get it sorted out.

GMRL

Ive worked at several shops including a Firestone, and have been doing alignments for a few years now. Ive noticed that just about anywhere, there are techs that are inexperienced trying to do things that are a little over their heads. Not calling anyone idiots, but the best way to learn is to do it.
Having said that, Ive noticed that some people will try to adjust caster by watching the caster bar graphs on the screen and not do a caster sweep after they adjust somthing.
Caster is not like camber or toe that can be easily measured simply by the angle it sits at, vertical or horizontal. You have to turn the wheel from left to right in order for the machine to measure that angle.

02LS1Z28BC

iTrader: (4)

Latest. I am ready to give up on firestone. I would like to find backyard mechanic wheel alignment tools and just do it myself.

Today, going back to Firestone, one of the two who worked on it originally on the 21st and 4 others got into a huddle under my car and just could not come to a consensus on what setting to set first, then the other, then when that didn't accomplish the desired result they loosened the other bolt (while the suspension was loaded, meaning on the wheels) and BINGO, the car/suspension snaps to the furthest setting. Then, the whole damn thing has to be done again. My service manual set says to suitably support the car on stands (unloaded front suspension) then set camber, then caster, then toe. These guys had the car on the rack on its wheels and were jumping all over one side from camber to caster and toe all without rhyme nor reason (seemed to me).

Years ago there was strings/wheel gauges or something that helped set this crap before these complicated machines came into play. Thats what I need. I want simple, to get them near perfect, then I can go show them a guy with strings and gauges can do a job they couldn't. They want to move the engine cradle to the left. I hear the cradle goes into pins (for alignment) then is hard bolted up into the frame. I hear no adjustment is possible for the engine cradle that would or could effect camber/caster/toe.

Right now, the car drives straight, but the left caster cannot be brought anywhere near specified range. I only replaced 4 bushings, and they are in the LCA's exactly the way they were before I switched them (except the one which was partially blown out of the bushing housing (left front forward bushing). The firestone rep told me the settings I have now will not wear or hurt my tire in any way. I hope it is true, the damn things (Eagle RS-A) are very expensive!

So, anyone know how GM does it without using the hunter machines? The service manual says (In "Front Camber and Caster Adjustment" step 2) to "Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information."

Maybe if I can figure this part out, I can get the damn thing set using old fashioned means like this service manual indicates.

Anyone?

GMRL

Heres the tool I use.



One end goes in a slot on the K member, the other goes on the control arm.
With the wheels on the ground, not jacked up. You loosen the control arm bolt and turn the adjusting sleeve untill you get it where you need it, then tighten the bolt up. Very simple.

What are the number they came up with?

leadfoot4

iTrader: (1)

That is the tool I referred to in post #30.....


An alignment is done with the car's weight on the wheels, just as its being driven down the road. jacking the car prior to the alignment is done just so the tech can check for slop in the ball joints, tie rods, wheel bearings, etc. The car is set up on the rack, the alignment heads are put on all four wheels, pull on the sway bars a couple of times to rock and settle the car, and then make the necessary adjustments.

You start by adjusting the camber/caster. On the 4th gens, this is done by loosening the LCA bolts and "finessing" the a-arm back and forth between both pivot bolts, until you get the settings you want. Usually, you set the camber first, then work on the caster, but you'll go back and forth a couple of times to get it "dead on". Then you do the other side of the car. Then do a "caster sweep", to double check the readings. (that tool is really handy here, because it not only helps you move the a-arm around, it also holds it in place while you tighten up the adjusting nuts)

Once the caster/camber are OK, you get in the car, start the engine and center the steering wheel, kill the engine, and put the steering wheel locking tool in place, and set the toe.

02LS1Z28BC

iTrader: (4)

OK, so I need to get this "tool" what is its nomenclature (name) and what else do I use to make sure the settings are correct. Are there clamp on manual dials/gauges/strings that can be used, or is it a given that I must have one of those humongus expensive alignment machines that take a garage to house. Input please? Thanks for all the help so far, nightmares about alignment and bushings prevail my sleep time (which wakes me up)...

Seriousely, how much is that "tool" whatever its official name is, and what else do I need to "DIY".

Thanks all!

Oh, Leadfoot, the numbers... Below!

Driven off the "rack" is:

LF Camber 0.4 RF Camber 0.3 (Both positive degrees, green)
LF Caster 6.9 (positive degrees, in red) RF Caster 4.7 (positive degrees, green)
LF Toe 0.03 (positive, green) RF Toe -0.03 (negative, green)

Front Cross Camber 0.1 (positive degrees, green)
Front Cross Caster 2.2 (positive degrees, in red)
Front Total Toe 0.01 (green)

Final question this post, will these setting cause any additional wear to tires (any of the 4)?

Cap'n Pete

iTrader: (2)

No, tire wear should be fine. 0.4° of positive camber is the factory spec.

If you do any sort of "performance" driving (ie: track) then you would want as much negative camber as you can get, but for the street, that's fine, it'll allow the wheels to follow the crown of the road. Also, once you're sitting in the car, it'll probably bring the tires close to 0° of camber (essentially, straight up and down).

From what I understand of a split in caster, having more on the left will mean the car will be less prone to drift left, and will tend to drift right. But because the crown of the road tends to lightly pull a car to the right, I thought that most cars were setup with a little more caster on the right side, not the left, to assist in keeping the car tracking perfectly straight under "normal" conditions.

Regardless, doesn't look like you're off by a lot, but I'm surprised they couldn't pull the left caster down to match the right.

Also, AFAIK, you would initally want to MAX OUT the caster adjustment first, then set camber. I'm not 100% sure if it's just "that simple" though?!

mitchntx

iTrader: (14)

For doing home alignments ...

I have a Longacre Accugauge and a pair of turn plates I bought off of eBay.
The alignment tool I bought at my local Oreilly's for about $30 I believe.

I use 4 jackstands and nylon kite string to "string" the car to make sure that I have set zero toe and the wheels tracking straight and true. Then I use toe plates and set my overall toe.

The first time I strung the car, I took measurements off of the subframes to ensure I was able to square up the car the same way each time and that my strings didn't create a trapazoid.

Tip:
Once you get your alignment set, tighten the holy ba-geezus out of the LCA bolts.

Cap'n Pete

iTrader: (2)

I think the "book" value calls for something like ~85 - 90 ft-lbs? However, they're BIG bolts, and that just doesn't "feel" like enough. I'm pretty sure I torqued mine to at least ~100 ft-lbs or maybe a shade more ... and nothing has come loose so far that I'm aware of .

leadfoot4

iTrader: (1)

The torque settings are 75 lb/ft for the "camber" bolts and 85 lb/ft for the "caster" bolts. Just for reference, my front end is set at:

Camber......0 degrees, both sides;
Caster.......5.5 degrees, left side; 6.0 degrees right;
Toe in.......0.4 degrees, both sides, total of 0.8 degrees