What exactly is my caster currently at? (Pics)

[blkhawk_jl]

I took some measurements with an angle finder. Aiming for 6 degrees and was getting different measurements based on placement. I just got some metalcloak UCAs and plan on installing them later this week.

1st pic is bottom of the knuckle, driver side

second is button knuckle, passenger

third is on the pumpkin, on one of the 2 holes

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[Roky]

I took some measurements with an angle finder. Aiming for 6 degrees and was getting different measurements based on placement. I just got some metalcloak UCAs and plan on installing them later this week.

1st pic is bottom of the knuckle, driver side

second is button knuckle, passenger

third is on the pumpkin, on one of the 2 holes

Looks like you’re a hair over 90 degrees so you’re a hair over 6 degrees caster. 90 is right at 6. This is assuming your rig is sitting perfectly level. I prefer getting read out from alignment rack, this is good to get an idea what you’re running , but my ocd likes to see the read out, lol.

 

[blkhawk_jl]

Looks like you’re a hair over 90 degrees so you’re a hair over 6 degrees caster. 90 is right at 6. This is assuming your rig is sitting perfectly level. I prefer getting read out from alignment rack, this is good to get an idea what you’re running , but my ocd likes to see the read out, lol.

thanks for the clarification. I thought that when I lifted the jeep it would throw off the caster. I'm 2.5'' up, shouldn't I be off by 1-2 degrees?

 

[Roky]

thanks for the clarification. I thought that when I lifted the jeep it would throw off the caster. I'm 2.5'' up, shouldn't I be off by 1-2 degrees?

Yes, you should’ve decreased caster as you lifted.

 

[Headbarcode]

I took some measurements with an angle finder. Aiming for 6 degrees and was getting different measurements based on placement. I just got some metalcloak UCAs and plan on installing them later this week.

1st pic is bottom of the knuckle, driver side

second is button knuckle, passenger

third is on the pumpkin, on one of the 2 holes

I've read here that the holes on either side of the pumpkin are best. Just make sure it's 100% flat. I had a raised burr on mine that needed to be dressed with a file.

thanks for the clarification. I thought that when I lifted the jeep it would throw off the caster. I'm 2.5'' up, shouldn't I be off by 1-2 degrees?

What lift, and what did it include?

Most anything shy of a leveled alignment rack would throw off the angle readings.

 

[blkhawk_jl]

I've read here that the holes on either side of the pumpkin are best. Just make sure it's 100% flat. I had a raised burr on mine that needed to be dressed with a file.

What lift, and what did it include?

Most anything shy of a leveled alignment rack would throw off the angle readings.

It’s a 2.5” RC spacer lift. Didn’t include anything other than the pucks & sway bar end links.

 

[quietpeen]

It’s a 2.5” RC spacer lift. Didn’t include anything other than the pucks & sway bar end links.

It didn't include longer shocks or shock relocation brackets?

 

[D60]

I find this whole thing fascinating 'cause I've also tried to get clarification here and I've personally never seen a definitive, absolute answer on where to check. The overall consensus seems to be the flats on the pig, but if questioned about discrepancies or specifics no one really has answers.

HOWEVER, x2 on checking for burs on the flats - I had to gently sand mine flat. Use your fingernail at the hole(s) and top and bottom edges. Pic here:
https://www.jlwranglerforums.com/forum/threads/caster-burrs-and-bird-feet.37640/

 

[blkhawk_jl]

It didn't include longer shocks or shock relocation brackets?

yea it came with shock relocation brackets

 

[AnnDee4444]

I find this whole thing fascinating 'cause I've also tried to get clarification here and I've personally never seen a definitive, absolute answer on where to check. The overall consensus seems to be the flats on the pig, but if questioned about discrepancies or specifics no one really has answers.

HOWEVER, x2 on checking for burs on the flats - I had to gently sand mine flat. Use your fingernail at the hole(s) and top and bottom edges. Pic here:
https://www.jlwranglerforums.com/forum/threads/caster-burrs-and-bird-feet.37640/

I'm fairly certain that this is for the JK ProRock 44, so it's not 100% definitive... but I think it's safe to assume that the JK & JL pinion is perpendicular to the cover mounting flange, and that the cover mounting flange is in the same plane as the circular lugs that everyone is using to check.

.

 

[AnnDee4444]

Another interesting observation that never gets mentioned is that if you have different front & rear ride heights, the vehicle rake must be taken into account when measuring the caster (with the angle finder on the axle method).

A 2-door with a 1" rake changes the pinion angle 0.59°.

 

[pangmaster]

Another interesting observation that never gets mentioned is that if you have different front & rear ride heights, the vehicle rake must be taken into account when measuring the caster (with the angle finder on the axle method).

A 2-door with a 1" rake changes the pinion angle 0.59°.

Thanks for pointing this out. Always learning!

 

[AnnDee4444]

Thanks for pointing this out. Always learning!

Re-reading what I wrote... I wasn't quite correct. The measured pinion angle is always the caster angle (+6°) regardless of rake.

Changing the rear ride height only (or carrying a heavy load) will influence the caster as I stated above. Changing the front ride height (like adding a winch) also changes the caster angle from the rake change, but not as much as the suspension geometry influences the caster angle.

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