Caster Adjustment: How to?
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From: Houston TX
Caster Adjustment: How to?
I need a little help here. I took my C5 in for an alignment to a new place that opened near my house (my old place moved to a new building 20 min away).
When they finished up, they gave me the print out and said that the caster on the drivers side was out (5.8° vs 6.9° on passenger), but they said that they couldn't adjust it. I told them that I was pretty sure that all three alignment parameters were fully adjustable on the C5. They said no, just camber and toe. Is this correct? (Other shops have never said anything about this.) I did't know for sure and I was in a hurry, so I didn't make a fuss about it then. I thought I'd find out for sure before taking it back in.
If caster is off and not adjustable, do I have something broken?
Assuming that caster is adjustable, how do you do it? What should I tell the alignment tech to do. (I know it is backwards for a customer to tell the tech what to do, but I would rather not pay to take it somewhere else.)
Any help is appreciated
Justin
When they finished up, they gave me the print out and said that the caster on the drivers side was out (5.8° vs 6.9° on passenger), but they said that they couldn't adjust it. I told them that I was pretty sure that all three alignment parameters were fully adjustable on the C5. They said no, just camber and toe. Is this correct? (Other shops have never said anything about this.) I did't know for sure and I was in a hurry, so I didn't make a fuss about it then. I thought I'd find out for sure before taking it back in.
If caster is off and not adjustable, do I have something broken?
Assuming that caster is adjustable, how do you do it? What should I tell the alignment tech to do. (I know it is backwards for a customer to tell the tech what to do, but I would rather not pay to take it somewhere else.)
Any help is appreciated
Justin
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From: Riviera Beach FL
Gm specs call for caster to be 7.4 to 6.4 degrees. Preferred setting is 6.9degrees. It is more important to get both sides as close as possible then to be at 6.9 as long as they are with in specs, when you find the right alignment shop.
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Last edited by Doug@MorosoPerformance; Aug 18, 2008 at 03:37 PM.
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From: South Western Ontario
To get technical, there are cam bolts on the front and rear bushings of the lower front A-arm. So, by moving one or both bolts, you can move the lower ball joint in, out, forward or backwards.
On the rear, there is only a cam on the front lower arm bolt. So, you can't adjust the caster on the rear. However, it's not really necessary to adjust it.
Peter
On the rear, there is only a cam on the front lower arm bolt. So, you can't adjust the caster on the rear. However, it's not really necessary to adjust it.
Peter
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From: Houston TX
Thanks for the replies. I didn't know if moving the cams affected the camber & caster or if it was just camber. I'll hopefully get it straightened out soon.
Last edited by MrPDJ; Aug 19, 2008 at 01:52 PM. Reason: left out something
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From: Charlotte, NC (formerly Endicott, NY)
You can increase caster by moving the rear lower control arm cam out in relationship to the front lower control arm cam (effectively moves lower ball joint forward) or you can add washers behind the front upper control arm mount (effectively moves upper ball joint rearward). To get the camber setting I wanted I had to have the cams moved all the way out and then add washers at the upper control arm to get the caster setting I wanted.
Camber and caster are interrelated. When you change one you change the other. When you change either one of them you change toe.
You may want to find a shop where the tech actually knows what he is doing.
Bill
Camber and caster are interrelated. When you change one you change the other. When you change either one of them you change toe.
You may want to find a shop where the tech actually knows what he is doing.
Bill
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Thread Starter
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Joined: Dec 2003
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From: Houston TX
Don't get it
OK, I took the car back into the shop and explained the situation. They agreed to re-do it free of charge. As they were about done, I went out there to check on things before they took the car of the lift. They still had it wrong!! I asked them why it was still out on caster and they said it was at full adjustment and that was as close as they could get it. I said that 1.9° cross caster aas not acceptable and that they needed to at least reduce the caster on the passenger side to try and match it up. I then stayed out there while they adjusted it again.
To make a long story short, they were trying to get the alignment dialed in on the driver's side by only adjusting either the front or rear lower A-arm bolt at a time. I asked if they would try adjusting them both at the same time and within 2 minutes they had it dialed in to factory specs!.
I can't imagine why you would return a customers car not in spec without trying a little harder. I think the real problem is that they only know how to do what the computer tells them.
In the future, I'll be going back to my old shop. Thanks for the help.
To make a long story short, they were trying to get the alignment dialed in on the driver's side by only adjusting either the front or rear lower A-arm bolt at a time. I asked if they would try adjusting them both at the same time and within 2 minutes they had it dialed in to factory specs!.
I can't imagine why you would return a customers car not in spec without trying a little harder. I think the real problem is that they only know how to do what the computer tells them.
In the future, I'll be going back to my old shop. Thanks for the help.
