I've searched and read alot of threads regarding using adj. upper and lower control arms and still can't really seem to find a definitive answer on which to go with.

In my particular case(front 1310 cv driveshaft vibration in another recent post I made) I'm looking at possibly having to raise my pinion up a few degrees. Should I use uppers and lengthen them or use lowers and shorten them? Or bite the bullet and get both?

Thanks

 

If you go uppers, you would be shortening them, if lowers you lengthen them (if lifted). Lowers cost more but that is the preferred ones to get first and are beefier than stock arms. The uppers are a PITA to install, I recall you have to cut one of the bolts off because of clearance issues. I would go lowers.

 

Lowers are much easier to adjust. Also most uppers don't go short enough to dial in the caster and pinion angle.
Get lowers.

 

I need to raise my pinion up so I would have to either lengthen the uppers or shorten the lowers. This I can't seem to get and answer on if this is ok or not?

 

What is telling you to lengthen uppers? I would imagine doing so would make your steering flighty with too much castor? Did you get an alignment and are they telling you to adjust your pinion this way?

 

Have seen this in at least one post here:
https://www.jk-forum.com/forums/show...engthen+uppers

From what I understand: Either lengthening the uppers or shortening lowers is going to lower the caster which will raise the pinion up a bit. Shortening the uppers or lengthening the lowers is going to increase the caster which will drop the pinion down a bit.

Or am I missing something here?

 

I guess it depends on where your current castor is now. Stock is +4.2 deg so lifting the Jeep will automatically change your castor just by the lift alone because of the new angles the lift creates on the axle. So, if this is so, to retain close to stock position, you need to reduce some castor by shortening the uppers or lengthening the lowers. This is what I understand. Although I could be wrong.

 

When you lift your jeep it will make you have less than proper (4.2) caster angle and this will cause you to pucker some unless you have driven older cars that drove this way new. The idea is to correct this back and it is done by making top arms longer or bottom shorter as stated. I am running mine at 5.1 with 3.5" lift and it tracks very well and has no wandering issues at all. I think front lowers and rear uppers are the preferd ones to buy first if you are going to buy them 2 at a time. Rear uppers will allow you to adjust out "binding" of rear coils. Front lowers generally have more adjustability than uppers from what I have been told. There is some more information on this in the newbie FAQ and in writeups.

 

That makes sense and how I understand it. I guess I'm just looking for a definitive answer on wether it's better to be lengthening uppers rather than shortening lowers to achieve the final result?

 

Either will work fine, the uppers are cheaper and Not harder to install. Any decent upper control arm will give you enough adjustment.

We sell both sets in the SRS bushings/heims