Adjustable Control Arm Help

I recently upgraded my lift and tires on my XJ and just had a chance to flex things out. I'm running JKS adjustable control arms (upper and lower) and 4.5" RE springs. I'm wondering if I set my control arm length too long. When a tire is compressed it is WAY forward in the wheel well, but when it is sitting on flat ground it's pretty much centered. I recognize that I need to lengthen my bump-stops, but I'm wondering if I need to shorten my control arms up a bit. It seems like if I did shorten my control arms, it would pull the wheel back a bit toward the firewall at full stuff and solve a lot of my rubbing issues - thought that would also move the wheel back toward the firewall on flat ground too. Any advice would be appreciated.

Thanks - Chris




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How long are your control arms now ?

At 4.5" of lift, with no drop brackets, your lower control arm should be about 16.25-16.50" long.

I would leave em where theyre at. If u shorten them itll look weird with the tires pulled toward the back of the fender. Just make sure the driveline isnt trying to separate at full compression. As u said just do bumpstop and call it good. I personnaly pushed my front axle forward 2 inches for approach angle and it seems to drive way better for some reason now to. Just my opinion though.

That's a normal issue with that much lift and no DBs (or LAs), you will just have to compromise between rubbing at full stuff vs. a centered wheel on level ground.
I would highly recommend drop brackets though, not only would they resolve this issue, they will greatly improve the ride and performance of your front suspension!

Thanks guys, I was torn on the drop brackets, and now I'm sold. Will post results. - chris

Extend your bump stops.

Drop brackets will help, but you still will need to have extended bumpstops.

I'm in a similar situation; if you add drop brackets, can you still use the same control arms? Or do they need to be shortened to the point you need to get a different set?

HouseVVares said:

I'm in a similar situation; if you add drop brackets, can you still use the same control arms? Or do they need to be shortened to the point you need to get a different set?

Click to expand...

Read this -> http://www.yuccaman.com/jeep/re_db.html

Be specific, what control arms ? are they adjustable ? what do they measure ? how much lift ?

HouseVVares said:

I'm in a similar situation; if you add drop brackets, can you still use the same control arms? Or do they need to be shortened to the point you need to get a different set?

Click to expand...

If you have adjustable arms, you won't need new arms since, at least every adjustable arm I've come across, will still adjust to stock length.

If you have fixed arms it will just depend on the type as Tim_MN said, but most if not all brackets do still allow the factory shim style adjustment in the lowers, so there's a little wiggle room.

I just installed a set of the RC DBs for a friend yesterday, I should have taken pics, but there's already a wealth of info out there! He has a RC 4.5" lift with 2" spacer for 6.5" total. Results will differ, but the lowers were just right at 16" (didn't measure but they were at least an inch longer before we started!) and the uppers were right around 15". There was plenty of adjustment to make them shorter still, about 3/4-1", with the newer style RC adjustable arms. The instructions with the DBs also has the chart for arm length. Keep in mind the lowers primarily locate the axle, the uppers adjust caster and pinion angle, so set the lowers first then adjust the uppers as needed to get the right angles.

I did this a couple month back - RE 4.5" to 5" lift and IRO adjustables.

Used the lower arms to center the axle and the uppers to setup the pinion angle. I recall the values published in different tables did not have much to do with reality.

The actual length was established on the alignment lift to achieve proper caster and make sure the wheel does not get too close when either full up or full down.

The drop brackets work great - they makes the suspension work better by providing a proper angle for the bump impact. Somehow they also made alignment easier and steering better...