Caster Angle

I have been trying to figure out the best way to measure the caster angle on a D44. I have seen two ways of doing it, and I am not sure which is the best/correct method.



The first:


Taken from http://www.bsfab.net/?p=13

Crash mentions this method as well in his Front D44 thread.


The second:


Taken from
http://www.jeepforum.com/forum/showthread.php?t=397243


Caster angle is the angle at which the ball joints are, so I would assume that the method using the dowel would show that better then using the flat part of the C.

The dowel and flat method are off by about 1.5*.



Side note: Sierra Drifter says he used 5* of positive caster. Billy says he used -5*, which I assume is negative.

Ive always thought that you go negative caster, as in rotate the top of the inner C towards the back of the Jeep. Is that thinking correct?

Starboard M said:

Ive always thought that you go negative caster, as in rotate the top of the inner C towards the back of the Jeep. Is that thinking correct?

Click to expand...

This is correct.

The pic posted is correct but that is POSITIVE caster.

http://en.wikipedia.org/wiki/Caster_angle

Ok, so I want negative caster. Now how do I go about measuring for it?

Starboard M said:

Ok, so I want negative caster. Now how do I go about measuring for it?

Click to expand...

No, you want positive caster as pictured.

I usually measure caster off of the hi steer arms once installed.

Starboard, that first picture you posted is how I measured my caster on the d44 I just built. If you use the dowel, I would say you need to have the threaded insert in the upper ball joint hole, otherwise it would give you a bad reading.

Positive is as pictured, negative would have the upper balljoint leaned forward.
http://en.wikipedia.org/wiki/Caster_angle

Doh, I swear Im not that retared:wierd:

So 4-7* of "positive" caster, or the top of the C rotated towards the back of the vehicle.

Begster said:

Starboard, that first picture you posted is how I measured my caster on the d44 I just built. If you use the dowel, I would say you need to have the threaded insert in the upper ball joint hole, otherwise it would give you a bad reading.

Click to expand...

When I use the dowel, that threaded insert is in there, which gives it a tight fit.


Right now, by the way of the flat angle, I have 5.2* of caster, and the dowel 6.4* of caster. Both of those are within spec, but I still would like to know which is the correct method to use.

I set mine up with the dowel method and 7* with the top towards the back of the vehicle...

HTH