Rear upper or lower or both?

LarryG

New member
So I will need a pinion angle adjustment to correct a 3-4" lift on my build. Is it recommended to add an adjustable upper control arm on the rear, or lower...or both? If you can, provide the "logic" with any recommendation. Thanks.
 

303DAILY

New member
Rear lowers are more than enough although most with that size lift don't do anything at all. Even the stock drive shaft can handle that. If you change it to a JE real shaft even less possibility of issues
 

wayoflife

Administrator
Staff member
So I will need a pinion angle adjustment to correct a 3-4" lift on my build. Is it recommended to add an adjustable upper control arm on the rear, or lower...or both? If you can, provide the "logic" with any recommendation. Thanks.

You only need to set your rear pinion angle IF you install an aftermarket u-joint style drive shaft. If you do, you need adjustable rear UPPER arms to set it.
 

wayoflife

Administrator
Staff member
Rear lowers are more than enough although most with that size lift don't do anything at all. Even the stock drive shaft can handle that. If you change it to a JE real shaft even less possibility of issues

This is not correct. FRONT lowers are enough to set caster but you NEED rear uppers to set pinion angle.
 
I've been schooling myself on this topic too. On average how much pinion correction with rear adjustable uppers is dialed in? From stock to 1 or 2 degs bellow drive shaft Angle to support new DC driveshaft. Does this cause any lubrication concerns of the pinion bearings if angle is far from Stock? Do coils bow out a bit more?

Hope this helps add dialogue to thread not hijacking, thanks
 

LarryG

New member
You only need to set your rear pinion angle IF you install an aftermarket u-joint style drive shaft. If you do, you need adjustable rear UPPER arms to set it.

Thanks again, Eddie. I will be installing aftermarket driveshafts after the PR60s are in, the suspension is in and I can measure.

The are a ton of vendors for the adjustable uppers- any recommendations? Style, strength, manufacturer, etc.?
 

cozdude

Guy with a Red 2-Door
Thanks again, Eddie. I will be installing aftermarket driveshafts after the PR60s are in, the suspension is in and I can measure.

The are a ton of vendors for the adjustable uppers- any recommendations? Style, strength, manufacturer, etc.?

Really look for arms that use Johnny joints so look at Evo, Currie, some synergy arms, etc
 

wayoflife

Administrator
Staff member
I've been schooling myself on this topic too. On average how much pinion correction with rear adjustable uppers is dialed in? From stock to 1 or 2 degs bellow drive shaft Angle to support new DC driveshaft. Does this cause any lubrication concerns of the pinion bearings if angle is far from Stock? Do coils bow out a bit more?

Hope this helps add dialogue to thread not hijacking, thanks

When running a rear aftermarket u-joint style double cardan drive shaft, you want to set your pinion so that it's in line with your drive shaft. This is done to prevent drive line vibrations. Your ring gear should help pump oil up onto the pinion bearings and if you have a ProRock 60 like the OP, it'll have additional proprietary oiling features that will help ensure the bearings get sufficient oil. Your coils will bow out a bit on a 4-door but it isn't that big of a deal. On a 2-door, it will be more pronounced and if you feel the need to correct it, I would recommend something like JKS adjustable lower spring perches.

Thanks again, Eddie. I will be installing aftermarket driveshafts after the PR60s are in, the suspension is in and I can measure.

The are a ton of vendors for the adjustable uppers- any recommendations? Style, strength, manufacturer, etc.?

As cozdude said, I personally would recommend arms with Johnny joints. Currie and EVO come to mind.
 
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