Maximum safe caster angle.

[ZXROM]

I'm curios as to how much positive caster everyone is running with their SPC adjustable control arms. I do my own alignments, I work at a shop, and right now I'm pretty close to 5 degrees with SPC uppers set at default and cams maxed out, I'm happy with how the truck handles, but I want to try and get 5+ degrees out of it. Mainly to get away from the cab mounts (I run 34s). I'm considering a "bmc", but first I wanted to find out how much positive caster is too much. If anyone has any experience with this chime in!

 

[Friggin Idiot]

Mine's at +4 deg. I wanted enough to feel stable and prevent bump steer over the friggin pot-holed mess we call roads.

 

[vipergrhd]

Just my 2 pennies

I don't think there is such a thing as safe caster angle it really depends on the suspension geometry and manufacturers design, that being said I'm sure you know this Caster is a non wearing angle you can max out your caster and will not eat up your tires but it can affect the way it handles and steer or even cause a drift or pull if not properly adjusted. Having 4-5* of caster is a lot for these vehicles unlike European cars which can go as high as 11* but that is just the way they are designed. I would play with it if I were you since you have access to an alignment machine and see what happens, I use to dial in my own alignments too when I had an alignment machine to play with.

 

[comtn4x4]

I can't weigh in on what's safe or unsafe as I'm no expert.
That being said I have run between 4-5* of caster for about 6 years without any problems. I am at 4.9* now which seems to be the max on my setup to get everything to align correctly.
A couple years ago I did have a tech at a reputable 4x4 shop tell me he wouldn't push the caster above 3* because it would cause wheel "flop". I immediately went to another shop who set it to 4.5*

 

[Spungus]

I have total chaos UCA's. They aren't adjustable like the SPCs, but they have a +4 caster built in. So when I get my alignment my caster is usually 4.75-4.95 depending on the tech. Running 285/70's and no rubbing whatsoever. If I had 285/75 then some kind of body mod would be necessary. But to answer your question, a caster at 5 isn't too uncommon as long as the geometry allows it like one of the replies was stating.

 

[That_Titanium_4RNR]

I run right at 6 if not a little over. Might not be applicable, but I figured the 4th and 5th gen geometry is probably very close. Truck drives great though

 

[vipergrhd]

Wheel flop?

I can't weigh in on what's safe or unsafe as I'm no expert.
That being said I have run between 4-5* of caster for about 6 years without any problems. I am at 4.9* now which seems to be the max on my setup to get everything to align correctly.
A couple years ago I did have a tech at a reputable 4x4 shop tell me he wouldn't push the caster above 3* because it would cause wheel "flop". I immediately went to another shop who set it to 4.5*

Did he explain what he meant by wheel flop? Never heard of the term and I've been turning wrench for almost 30 years.

 

[BackOff]

Jaming in more caster with the SPC UCAs will move your tire into the body mount more.
The 3rd gen guys figured it out.
Orange is caster# the SPC arms do.

 

[That_Titanium_4RNR]

Jaming in more caster with the SPC UCAs will move your tire into the body mount more.
The 3rd gen guys figured it out.
Orange is caster# the SPC arms do.

Maxing caster via LCAs is a better option for tire fitment for sure. Use UCA for camber. This video explains it well too YouTube

 

[comtn4x4]

Did he explain what he meant by wheel flop? Never heard of the term and I've been turning wrench for almost 30 years.

I didn't get into it too much with him as he couldn't answer my primary question which was why didn't you leave it with the 4* it had when I brought it in.
Basically he said the steering wheel would feel heavy and smooth movement of the wheel would be inhibited due to "wheel flop"
Most likely a lazy tech who didn't want to align it again