RPG Upper Control Arms

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

thatJeepguy

FRF Supporting Member
Supporting Member
Joined
Nov 28, 2021
Posts
2,460
Reaction score
3,650
Location
GA
I wouldn't say I am a RPG fan boy either. I picked a setup I wanted and figured all their products would work together so to speak.

But on the upper control arms I have a couple thoughts.

Here is the deal. Fact is you need some adjustments to do alignments.

The factory uses slots in the lower control arm for this.

There are kits to delete the slots. At that point you have to do you adjustments with the upper control arm. You could definitely do that with the RPG upper arms but Holy hell it would be a ton of work..

There are arms that are adjustable but we are talking aluminum here so for me I want as much thread engagement as possible. Which means I leave the lower slots as adjustment points and use the RPG arms which do NOT have provisions for on vehicle adjustment.

I do have a slot reinforcement kit coming.

Retains slots but reinforces the lower control arm mounting points.
I noticed the frail adjustments for camber and caster on the lowers the other day. How are techs supposed to get a good alignment done with such a crude adjustment . Cam bolts always seemed like a horrible idea in general to me…
 

Old-Raptor-guy

FRF Addict
Joined
Jul 25, 2021
Posts
1,872
Reaction score
4,333
Location
USA
I noticed the frail adjustments for camber and caster on the lowers the other day. How are techs supposed to get a good alignment done with such a crude adjustment . Cam bolts always seemed like a horrible idea in general to me…
You must be some sort of engineer, I think you are over thinking it a little. The factory doesn't use cam bolts, (on our lower control arms) i assume that is because they are not as strong. 1/2 the bolt is missing for the cam washer. the factory lower bolts are torqued to just under 300ftlbs (294 i think) it takes a pretty good hit to knock one out of alignment.

The alignment rack has slip plates that slide. So as you make adjustments the tire doesn't have to slide (which would take a ton of force) the alignment readings are live so you make an adjustment, get the readings in the green and tighten it down. make it sure doesn't move. Toe setting is the worst, the readings always move as you tighten down the locking nut. You have to anticipate it and sometimes be in the red and as you tighten it will go into the green. Probably does sound like a pain, but do it enough and it becomes second nature.
 
OP
OP
Sig Fanboy

Sig Fanboy

Full Access Member
Joined
Apr 2, 2023
Posts
786
Reaction score
1,715
Location
WV
You must be some sort of engineer, I think you are over thinking it a little. The factory doesn't use cam bolts, (on our lower control arms) i assume that is because they are not as strong. 1/2 the bolt is missing for the cam washer. the factory lower bolts are torqued to just under 300ftlbs (294 i think) it takes a pretty good hit to knock one out of alignment.

The alignment rack has slip plates that slide. So as you make adjustments the tire doesn't have to slide (which would take a ton of force) the alignment readings are live so you make an adjustment, get the readings in the green and tighten it down. make it sure doesn't move. Toe setting is the worst, the readings always move as you tighten down the locking nut. You have to anticipate it and sometimes be in the red and as you tighten it will go into the green. Probably does sound like a pain, but do it enough and it becomes second nature.
Ima pretend I know exactly what all that means
 

TomDirt

FRF Addict
Joined
Jan 3, 2022
Posts
3,503
Reaction score
10,018
Location
Hesperia CA
"There are kits to delete the slots. At that point you have to do you adjustments with the upper control arm. You could definitely do that with the RPG upper arms but Holy hell it would be a ton of work.."

Yup.
 

Old-Raptor-guy

FRF Addict
Joined
Jul 25, 2021
Posts
1,872
Reaction score
4,333
Location
USA
When I first started looking at upper control arms I thought the on truck adjustment capability would be nice. But then I watched one of the EXO or other baja run videos on YouTube and they had a truck down, it had a billet control arm come apart, it was only in the frame for about 3 seconds but you could clearly see the heim joint had pulled out of the control arm. This is caused by either one of two things. not enough threads into the control arm OR the locking system (jamb nut or pinch bolts) coming loose and causing back and forth pressure to be put on the threads until they failed.

Right then I decided the on vehicle adjustment was an extra failure point and didn't want it.
 
OP
OP
Sig Fanboy

Sig Fanboy

Full Access Member
Joined
Apr 2, 2023
Posts
786
Reaction score
1,715
Location
WV
Actually I was watching a video on the Kibbetech(?) UCA’s today. I guess they are the type that can be adjusted. I guess I’ve learned a lot about UCAs today
 

Old-Raptor-guy

FRF Addict
Joined
Jul 25, 2021
Posts
1,872
Reaction score
4,333
Location
USA
The kibbetech only has one pinch bolt, (not necessarily a bad thing) other designs have 2. The ones I have seen with 2 have a warning saying "pinch bolt torque not to exceed 10 ft lbs. That is only 120 inch pounds. not much for a part that will see a ton of vibration. Kibbetch may have more aluminum/threads with one bolt and as such may or may not be better. if the pinch bolt comes loose thread fatigue/wear will happen pretty fast.

which is true of a jamb nut set up also. Just that jamb nut torque is substantially more so less chance of loosening from vibration.
 

OEMPlus Raptor

OEM preferred....
Joined
Aug 17, 2020
Posts
1,061
Reaction score
1,133
Location
Oxnard CA
Top