Inertia
Well-Known Member
Caster, a bicycle has caster .
That's how I remember .
That's how I remember .
Please critique my home front-end alignment method
- Thread starter 1973dust
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67Dart273
Well-Known Member
Or "caster wheels" like on the front of a shopping cart. Interestingly, "caster wheels" do not normally have caster!!! (The "spindles" are vertical!!!)
MOPAROFFICIAL
Oogliboogli
Wow, that's cheap! I wonder if it's any good?
MOPAROFFICIAL
Oogliboogli
Instructions are really vague.
the car has to be level for the readings to be any good. Wheels off and at ride height imo
I have a Longacre of that type. You don't put it on the rotor surface. (Crazy "pals" in China!) You take the dust cap off (temporarily snug the bearings to remove any wiggle), and attach it to the center of the drum/rotor. Leave the tires on it (inflate all 4 correctly). If you have aluminum rotors (Wilwood, etc.), Longacre sells an adapter that screws onto the spindle.
For toe, I used to use a 2 x 4 with some bent up shelf brackets. But now I use the cheap toe plates sold on ebay or Amazon. Much better.
Also, I use (2) 12" square vinyl floor tiles under each tire with sand between them as turn plates. Don't use the self-adhesive kind- the backing makes a mess.
https://www.youtube.com/results?search_query=using+longacre+caster+camber+gauge
Don't be afraid to check and set as much as you want. You'll develop a "feel" for what it wants.
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"max caster"isn't the end all be all .
You have to consider the difference between reading in each side vs the other. ("cross" camber and ""cross caster") you want the camber reading to be close on one side to what it is on the other, and you want the caster the same way. If a car pulls one way or the other because of alignment, it's because there's too much difference in the readings between one wheel and the other.
A car will pull if the camber on the driver side is too much more positive than the right, caster is the opposite.
You want a little offset in readings between left and right if you have heavily crowned roads or the car will pull "downward " of the road crown (usually right) usually 1/4 to 1/2 degree higher camber on the driver side or 1/2 degree or (slightly more) positive caster on the right than the left. But set the other reading as even with the other side as you can get it. I like to do the road crown comp with caster more so than with camber since camber can wear tires and caster won't
There are pretty wide tolerances on most alignment specs, but you still need to keep the left to right "cross" readings within a reasonable amount of each other.
Before we had specs preprogrammed in the alignment machine for every car and truck made in the last 50-60 years to pick from we used to set almost all rwd cars and trucks pretty much the same as any other and out customers didn't wear their tires "funny" and we didn't have any handling complaints.
Remember back when you could get either manual steering or power steering, caster was always spec'd lower on a manual steering car.
We'd set left camber around+1/2, right camber around +1/4 to +1/2, and caster fell where it would, but the biggest thing we would pay attention to was the "cross"reading, setting the driver side caster 1/2 degree or slightly greater, lower than the passenger side.
Ever have a shopping cart with a stuck wheel? Now you see what caster does. Or a "regular" motorcycle vs a "chopper" ? The chippers had more caster, which made them more stable cruisin down the highway and the other one that wasn't a chopper would be better in twisty roads and easier to steer on that situation?
You have to consider the difference between reading in each side vs the other. ("cross" camber and ""cross caster") you want the camber reading to be close on one side to what it is on the other, and you want the caster the same way. If a car pulls one way or the other because of alignment, it's because there's too much difference in the readings between one wheel and the other.
A car will pull if the camber on the driver side is too much more positive than the right, caster is the opposite.
You want a little offset in readings between left and right if you have heavily crowned roads or the car will pull "downward " of the road crown (usually right) usually 1/4 to 1/2 degree higher camber on the driver side or 1/2 degree or (slightly more) positive caster on the right than the left. But set the other reading as even with the other side as you can get it. I like to do the road crown comp with caster more so than with camber since camber can wear tires and caster won't
There are pretty wide tolerances on most alignment specs, but you still need to keep the left to right "cross" readings within a reasonable amount of each other.
Before we had specs preprogrammed in the alignment machine for every car and truck made in the last 50-60 years to pick from we used to set almost all rwd cars and trucks pretty much the same as any other and out customers didn't wear their tires "funny" and we didn't have any handling complaints.
Remember back when you could get either manual steering or power steering, caster was always spec'd lower on a manual steering car.
We'd set left camber around+1/2, right camber around +1/4 to +1/2, and caster fell where it would, but the biggest thing we would pay attention to was the "cross"reading, setting the driver side caster 1/2 degree or slightly greater, lower than the passenger side.
Ever have a shopping cart with a stuck wheel? Now you see what caster does. Or a "regular" motorcycle vs a "chopper" ? The chippers had more caster, which made them more stable cruisin down the highway and the other one that wasn't a chopper would be better in twisty roads and easier to steer on that situation?
shep76
Well-Known Member
I know this is an older thread. I have a cheap harbor freight angle finder I was going to use to measure camber/caster using the 20 degree method. My question is, what do the real caster/camber gauges do that is different than my angle finder? Does it just eliminate the need for doing calculations? Are they more accurate? I just rebuilt my whole suspension and have the offset bushings so getting ready to tackle the alignment.
Second question since "stops" were mentioned. I notice my brake hoses are pulled pretty tight when I go full right or left. Is my "stop" missing something? Or is that bolt head really the only thing that limits it?
Second question since "stops" were mentioned. I notice my brake hoses are pulled pretty tight when I go full right or left. Is my "stop" missing something? Or is that bolt head really the only thing that limits it?
racerjoe
Well-Known Member
My assumption is the Longacre bubble gauge is calibrated in such a way that the multiplication factor isn't needed. If you look at it closely, the glass of the level has an arc, it isn't flat like a normal level.
Never saw a ‘flat’ level. How does the bubble find center?
racerjoe
Well-Known Member
OK, how would you describe it? Not curved, straight, linear, in line, etc. I'm pretty sure he got the point.
shep76
Well-Known Member
Yeah, I think I of figured out the advantages. It has two camber bubbles which should help increase accuracy. You turn the wheel 20 degrees one way then zero it out before turning it 20 the other so that would negate the calculations. I'm going to give my little harbor frieght angle finder and home made turn plates (plastic bags with wd40) a shot and see how close I can get before spending any money.
ir3333
Well-Known Member
I always adjust the upper A arm cams to get as much caster as possible...you don't need to know the number.
With weighted thread restrict the camber to 1/4" off vertical at the top for each tire in the direction + or - that your manual suggests, and this will get you about a degree of camber.
Using a 28" piece of flatbar along each wheel set toe in to 1/8"
Now drive to a straight stretch on a quiet highway, check self centering on a slow turn. Run the car up to speed and let go of the steering wheel. If it tracks straight you're golden.
...i can hear the murmurs!
With weighted thread restrict the camber to 1/4" off vertical at the top for each tire in the direction + or - that your manual suggests, and this will get you about a degree of camber.
Using a 28" piece of flatbar along each wheel set toe in to 1/8"
Now drive to a straight stretch on a quiet highway, check self centering on a slow turn. Run the car up to speed and let go of the steering wheel. If it tracks straight you're golden.
...i can hear the murmurs!
shep76
Well-Known Member
I like it! I already have the cams set for max caster. It has about 0 camber right now though so will need to make some adjustments. The general consensus seems be -0.5 camber.
racerjoe
Well-Known Member
This is what I do. Plastic bags and WD work great. I made some toe plates with some scrap 1x6s. I also cut a piece of hardwood that lands on the edge of the wheel so I have a nice repeatable place to put the level. I also marked the ground with tape showing 20 degrees both ways since the steering angle is more than 20 degrees. If you really want to be precise, the multiplication factor is actually 1.42 for 40 degrees total sweep, not 1.5.
What lower ball joint is that? It doesn't have a steering stop at all. The "nub" circled in this picture is the steering stop. They vary a bit from one manufacturer to the next, but it should have one.
You do need to know the number, because there's no way to tell by just looking at the UCA cams if the caster is actually the same side to side. Just because you set the cams the same does not mean the caster is the same, there's too much tolerance on these cars even in the suspension points. Some might get away with it, but others will definitely not be the same or even "close enough"
And even if it tracks straight it doesn't necessarily mean the caster is the same side to side, your cross caster can be canceled out by other alignment discrepancies. Between the cross-caster, cross-camber, toe and some road crown you could drive straight and still eat tires.
I'm all for setting alignments at home, I do. But I'd consider an actual caster/camber gauge and a set of toe plates to be the minimum if you intend to do more than just drive it a short distance to an alignment shop. While technically an angle finder and a level with some math can get you to the right answer you're not going to get a particularly repeatable set up that way. Having even some basic alignment equipment makes a huge difference in the repeatability of the measurements, which improves the accuracy dramatically.
shep76
Well-Known Member
Thank you. What year is that from? I looked on Rock Auto and I don't see that nub on any of the 69 Dart lower ball joint pics... I got mine from ESPO.
Here is a thread of mine with some great info provided by a variety of people:
Alignment at home and aftermarket UCAS too.
Alignment at home and aftermarket UCAS too.
The picture is a 73+ disk lower ball joint. Wasn't sure what year car we were talking about, kinda assumed from your screen name it was 73+.
You're right though, the earlier cars don't have that steering stop on the lower ball joint.
shep76
Well-Known Member
Ha. My bad, I should have put my car info. I was made in 76! Car was made in 69.
A ‘level’ has to have a curve, some have a very slight curve for better accuracy. My Starrette machinist level is the way, very touchy. My 4’ carpenter levels are more lenient. A perfectly flat bubble will never find center. Now to check a ‘level’ lay it down on surface, mark the bubble, then turn 180 degrees to see how close to the mark you made. Split the difference and there’s your perfect spot. The better levels have micro adjustments to set them, they’re delicate so a little bump will make them off. In a hurry, reverse it each time to find its center.
ir3333
Well-Known Member
72blu makes an excellent point that knowing caster side to side is important. Newer vehicles have enough adjustment to create a problem. I've never known anyone to get more than 1 or 2 degrees of caster max. on our old A bodies and in most cases you can't get in to trouble side to side. Just do some careful test driving after you make your adjustments or take it to a professional.
racerjoe
Well-Known Member
Thanks for the lesson. However, a front end alignment is hardly machinist level accuracy (no pun intended). Nor do I have experience with anything beyond carpenter type levels. Please explain how the Longacre tool works without needing the multiplication factor. Is it a calculated radius for the level?
shep76
Well-Known Member
Have you guys found that you have to lower your car pretty far below the manual settings in order to get a negative camber? I think the manual has the A-B measurement at 1 7/8, I'm down to about 1.5 inches with a half inch for the bump stop and I still have some postive camber before adjusting the front cam.
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