Caster Correction Question
- Thread starter LFD2037
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Yeah what happens when you rotate the axle housing by 4.x degrees you also get an additional bit of lift from the spring perches moving and 'de-arc' of the spring. So the net correction is correct, but add in the small amount of lift, and the angles change again a bit.
I did my math, decided 5/8" of total slotting was needed, ended up with slightly less caster than I expected.
I did my math, decided 5/8" of total slotting was needed, ended up with slightly less caster than I expected.
But there's also an additional gain aswell. Because as there is 4.3 degrees of caster rotation for 14mm. The caster angle is measured from level. The axle instant centre never moves, nor does the chassi point. So the arm (both front and rear mounting point heights change around the axle centre.
It can all be done with math, and worth everyone learning. And then confirmed by a prac test.
It can all be done with math, and worth everyone learning. And then confirmed by a prac test.
I have a std suspension and hight is 520mm from centre of hub to under the guard
my caster at this point is left 1.42 degree, right 1.38 degree
if I do the 14mm slot what would my caster be
if caster is 3 degree std why is mine those numbers
from the bump stop to the diff messures 50mm which is what the manual says is correct
all the hight measurements are right
regards peter
my caster at this point is left 1.42 degree, right 1.38 degree
if I do the 14mm slot what would my caster be
if caster is 3 degree std why is mine those numbers
from the bump stop to the diff messures 50mm which is what the manual says is correct
all the hight measurements are right
regards peter
from all my measuring those heights are correct for a stock truck. I've never actually had and alignment on a stock truck so I can't say if those caster readings are unusual or not. I've always assumed that these trucks were set up at the factory to be @ 3*.
Is your front axle in good shape? New trunion bearings and the wheel bearings aren't loose?
Man, every thread I see you posting on you are being a dick to ppl. What's the deal. Your knowlege is inferior, we know. Guy is just asking a question. You either help him or just move on, not insult his inteligence. Don't forget there was a time when you started off and needed answers. Geez.
EDIT... ^^^^ Guidance/help spoken from a true proffesional. (Landtank)
I've wasted plenty of time helping Peter out for your information. If people aren't willing to even add 2 numbers together and try to learn. Can't hold their hand all their life.
Seriously. This guy is like the cancer of these forums. Nothing useful, just condescending ramblings in every suspension thread.
mark all i ask was a simple question, if normal caster is 3 degree why is mine the numbers i put up, i dont see it saying 3 degree, so why the smart ass answer
^^^^^
if I was the original poster, I would go with what Pin_Head posted - just sayin'
you have also told me to buy new parts as well that didnt help, like a power steering box that you said was stuffed, i took it to the shop and got a new one 900 bucks later and the guy said it was fine
wasted of my time and money seeing you, i asked you to drive it to see what you thought and you didnt, your good at down grading people when you know every thing, so what is all your nowledge on the 4wds and where did you get your expeariance from
theres alot of people that can fix cars part that doesnt mean they know all the teck stuff about them
when i tell you some thing all you can do is blame me for not looking im so over all your bull**** and so is every one else, get over your self, your nmot that good at what you do
Im very good at what I do. You just simply wont listen and think you know best. Your caster was perfectly fine at +4 degrees, set up for towing. You insisted your problem was still caster and took it back to stock. Cant help people that wont listen.
i took it back to stock to get std factory setting, as you said, did i have a reading before the lift was put in
anyway i find you dont explain your self properly to people that dont understand, you need to learn more people skills
end of convensation
anyway i find you dont explain your self properly to people that dont understand, you need to learn more people skills
end of convensation
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I too dont know what an INVSINE button is. Its a simple Pie solution.
Cercumference = 2x Radius x Pie (3.14)
185mm x 2 = 370mm
370 x pie = 1161.8 (cercumference of a circle) a circle = 360 degree's
1161.8/ 360 = 3.22mm per 1 degree
14mm/ 3.22 = 4.34 degree's of rotation
But none of the lower radius arm bushes are on a fixed axis. Only the chassi and the axle instant centre and chassi mount is. So the same math is applied to distance from the chassi mount centre to each of the lower bush centres to find the difference in distance travelled altering the numbers slightly. Then as 86tuning said, once the housing rolls back the lift height lowers a little altering the number slightly again. But we are only talking points of a degree here.
I have measured caster on a few stock trucks (510mm front measurement). +2.2-2.4'
The factors noone takes into consideration is the rear lift height that affect caster also, or bush condition. Plus the fact of human error of differences from toyota housings/or lifts arent exact the same, or whats written on the box.
The math and tech is alright, but the main factor is simply finding where your caster currently is, and how much you need to increase it.
Previous test.
Cercumference = 2x Radius x Pie (3.14)
185mm x 2 = 370mm
370 x pie = 1161.8 (cercumference of a circle) a circle = 360 degree's
1161.8/ 360 = 3.22mm per 1 degree
14mm/ 3.22 = 4.34 degree's of rotation
But none of the lower radius arm bushes are on a fixed axis. Only the chassi and the axle instant centre and chassi mount is. So the same math is applied to distance from the chassi mount centre to each of the lower bush centres to find the difference in distance travelled altering the numbers slightly. Then as 86tuning said, once the housing rolls back the lift height lowers a little altering the number slightly again. But we are only talking points of a degree here.
I have measured caster on a few stock trucks (510mm front measurement). +2.2-2.4'
The factors noone takes into consideration is the rear lift height that affect caster also, or bush condition. Plus the fact of human error of differences from toyota housings/or lifts arent exact the same, or whats written on the box.
The math and tech is alright, but the main factor is simply finding where your caster currently is, and how much you need to increase it.
Previous test.
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I dont know how to explain it so you can understand it. Its not always a simple answer.
The Toyota caster spec is 3 degrees, plus or minus 1 degree, so it is a range of between 2 to 4 degrees. 50 mm off the bump stop (what Toyota calls the follow spring clearance) is a little high, since the spec is 36 mm. This height alone would cause a caster change of approximately - .8 degrees, which can account for your slightly out of spec caster of 1.4 degrees.
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Not to derail this great thread but why does Toyota spec less caster in earlier 80's?
