Alignment specs?
- Thread starter 87 Grey T
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seedling
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- Jun 17, 2012
I don't know much about alignment issues, as it relates to our cars. However, I have plenty of experience with it in Jeeps.
How I always remembered it was a fishing reference an old timer once gave me. As he said Caster is kind of like how far out you project / throw your bait. Kind of sort of but, not really, as it is the angle of the steering pivot, measured in degrees.
Like I said, I have no idea what it should be for our cars. However, if it were viewed from the side, the caster is the tilt of the steering axis. When the wheel is in front of the load the caster is positive. I want to say like 3-5 of positive caster is the typical range of settings, with lower angles being more prevalent on heavier vehicles (I think to make it easier to steer)?
I'm sorry if I'm only telling you what you already know here! However, I'm really kind of curious as to what it should be as well. In that, I always thought that it should be slightly less than what you have there? Again 3-5 iirc??
I do know that if the caster is out of adjustment, it can cause problems in straight-line tracking. And I think (although not 100% sure though), that if the caster is too positive that the steering will be kind of heavy and the steering wheel might buck when you hit a bump?
Anyways I'll be anxious to see what the settings should be and or what you'll need to do to correct them (if anything)!
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How I always remembered it was a fishing reference an old timer once gave me. As he said Caster is kind of like how far out you project / throw your bait. Kind of sort of but, not really, as it is the angle of the steering pivot, measured in degrees.
Like I said, I have no idea what it should be for our cars. However, if it were viewed from the side, the caster is the tilt of the steering axis. When the wheel is in front of the load the caster is positive. I want to say like 3-5 of positive caster is the typical range of settings, with lower angles being more prevalent on heavier vehicles (I think to make it easier to steer)?
I'm sorry if I'm only telling you what you already know here! However, I'm really kind of curious as to what it should be as well. In that, I always thought that it should be slightly less than what you have there? Again 3-5 iirc??
I do know that if the caster is out of adjustment, it can cause problems in straight-line tracking. And I think (although not 100% sure though), that if the caster is too positive that the steering will be kind of heavy and the steering wheel might buck when you hit a bump?
Anyways I'll be anxious to see what the settings should be and or what you'll need to do to correct them (if anything)!
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Well the camber and toe are right about where i wanted it but its the caster im kinda concerned about. I took it for a quick 10min. ride on crappy roads and it felt ok. Havent driven the car in about 12 yrs and the whole suspension and brakes are brand new, i was trying to brake in the pads at the same time.
seedling
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- Jun 17, 2012
12 years?? Wow! Well, I can't wait for one of the gurus to come along and shed some knowledge on this subject. In that, I decided to go look it up and yet I still can't find anything specific. But, for the record here is what gnttype has to say about alignment.
http://www.gnttype.org/techarea/suspension/align.html
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http://www.gnttype.org/techarea/suspension/align.html
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seedling
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- Jun 17, 2012
Wow! Man I love the dark grey, the silver and the white T's!! I even like some of the creme kind of colors! But, that car is fine! What wheels are those? And how in the world could you let that thing sit??? Oh my!! Very nice car dude!!
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626gn
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- Feb 15, 2009
Sorry a bit off topic but are those Centerline Competition Eliminator wheels? If so, what size? I almost ordered a set but backed out because I wasn't sure how they'd look on the car. I shouldn't have... they look sharp!
Thank you, yes they're Centerline Eliminators 17x9.5 in back, 17x8 up front.
You can develop edge wear issues on the front tires.
seedling
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- Jun 17, 2012
I had always heard that it was toe / camber that caused edge wear. Now if I butcher any of these terms, then please forgive me. Because a technician I am not, as I am merely an enthusiast seeking knowledge myself. Point being is that I may be wrong here, however, from what I can gather, tire wear is affected in this order:
1) Toe – is the most important alignment angle as it shows how Parallel the front wheels are and the angle could be:
a) Zero Toe - meaning the edges of the tires are theoretically aligned;
b) Toe In – the front edge of the tires are closer together and the rear edge is closer together.
c) Toe Out – the front edges of the tires are farther apart and the rear edge is closer together. Each vehicle being somewhat different and requiring a certain amount of Toe. For example, a lifted Jeep with over-sized tires actually calls for the front edges of the tires to Toe In (so they are aimed at each other slightly). This is due to the stress and subsequent stretch of the front end components that highway speeds can exert on them. This is especially true of one with Big Tires. In that, the negative Toe / Toe In will actually open up at highway speeds thereby allowing the Jeep to end up having a perfect amount of Toe while on the road at speed.
2) Camber – refers to the tilt or angle of the wheels when you are facing the vehicle. The best example I can give here is the Tuner Car Image below with all four wheels leaned in so far that I don’t know they drive it!
3) Caster – is the forward (negative) or rearward (positive) tilt of the steering axis (as viewed from the side of the car). Caster only applies to the front wheels as they are the only ones that steer. Which is why Caster is sort of an oddball, as its greatest effect is steering stability, steering effort, etc. So that often makes it the most ignored as well, since it does not directly affect tire wear, per say.
See thats exactly what i thought, tire wear would mostly be caused from a camber or toe issue. But see im still kinda concerned about that caster # being in the 6* range. In my research the last few days that caster # is the highest ive seen. I hope thats not a bad thing.
seedling
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- Jun 17, 2012
Forgot to add the image earlier! But, this is camber gone awry!!
Caster has a lot to do with steering, stability and tracking. So is the car wandering at all? Or does the steering feel unresponsive?
With your uppers being adjustable you would think that the technician could get it as close to perfect as possible. Although that could be part of the design element too? In that, they may have intentionally added more caster for improved steering or something? Who knows? However, you might consider emailing UMI to see what they think about your alignment specs? I'd be curious to see what they had to say about it though that's for sure, as I plan on running some tubular arms myself. So if you do email them, please post up what they say?
Thanks!!
Spelling Edit!
Caster has a lot to do with steering, stability and tracking. So is the car wandering at all? Or does the steering feel unresponsive?
With your uppers being adjustable you would think that the technician could get it as close to perfect as possible. Although that could be part of the design element too? In that, they may have intentionally added more caster for improved steering or something? Who knows? However, you might consider emailing UMI to see what they think about your alignment specs? I'd be curious to see what they had to say about it though that's for sure, as I plan on running some tubular arms myself. So if you do email them, please post up what they say?
Thanks!!
Spelling Edit!
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achalmersman
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- May 28, 2012
Toe and camber are the primary wear angles but charlief1 is right about the caster wear in this case. Depending on tire width amd driving habbits caster can and will cause edge wear due to the significant amount of camber change when the wheels are turned due to the high caster. Other than that there are not really any drawbacks as long as you don't experience any bump steer, etc. I personally like high caster in all my vehicles. I even have one side of my diesel pickup at 5 degrees. I prefer the tight feel.
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Well the steering didnt seem to wander but im sure its much better than it was originally cause before the alignment i put in an astro van steering shaft. Ill call UMI tomm see what they think.
seedling
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- Jun 17, 2012
Not to disagree with either of you. However, I'm not so sure that isn't one of those common misconceptions about steering geometry. Because the caster is the negative or positive angle of the front wheels axis.
Although I am not disputing what you are saying. Since what you are saying is true. It is just that if you really think about, "Caster" in and of itself does not "Directly" affect edge wear. To illustrate that fact, I would to your quote. As I feel as though you were spot on when you said, "edge wear due to the significant amount of camber change when the wheels are turned due to the high caster."
The key phrase there being "Camber Change". So thats why I feel as though "Caster" (in and of itself) is not the direct cause of edge wear! In that, it is a result of a "Camber Change", just as you had suggested.
Anyways I see both of your point and I'm not disagreeing with you. As I'm merely attempting to suggest that edge wear is not a direct result of Caster alone.
achalmersman
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- May 28, 2012
You don't need to explain alignment measurements to me lol. I worked for the company that makes the alignment equipment (Hunter Engineering Company). There's nothing to debate you are correct. It is not a direct wear in and of itself if the car were going straight down the road all the time. But that isn't the case because in the real world the cars take turns. No matter how you slice it 2 cars all else being equal and driven enthusiastically one with 3 degrees caster one with 7, the one with 7 will present with more edge wear from camber change during cornering and turning. Yes its the instantaneous camber (only when wheels are turned) causing the wear.....but its the caster causing the camber. Call it what you want.
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seedling
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- Jun 17, 2012
I understand and I see your point! And I mean no disrespect nor offense to anyone by saying any of that. So I apologize if I came across as being an ass! As you guys obviously have far more experience with our cars than I do. And it sounds like you would have a far better understanding than I do anyways.
What basic understanding I do have comes from being a Jeep fan anyways, as I've tinkered with them for years. And I learned about bump steer the hard way. Only when you get "bump steer" in a Jeep it's called the dreaded "Death Wobble" and the first time it happened to me, I was on a divided four lane interstate (grassy median in the middle) and this is no joke I stopped traffic on both sides when it happened to me! It must have been crazy looking because they all stopped!! True story!!!
So after my heart started beating again I made a trip to the local hospital to get the drivers seat of my Jeep removed from my backside (where my butt had puckered so bad it sucked the seat in with it). And I decided right then and there that I would figure out all I could about all of that.
So sorry! As my ADHD, OCD, literal sense just took over! Lol!
And again my apologies, as I meant no offense!
achalmersman
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- May 28, 2012
Sorry man no offense taken. I probably read a little to far into your use of the word "misconception" lol.
The death wobble is no joke. Glad you got it sorted out. It can be very dangerous just as you described.
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