Saturday, December 26, 2009

Installing TeraFlex LCA on Jeep Wrangler Unlimited

After I lifted my Jeep and put larger tires on it, she started wondering around a bit on the highway.  It wasn't terrible, but it is annoying on long trips.  Everything in the suspension of a vehicle is connected.  When you change one thing it changes something else.  When I lifted the suspension it changed the angle of the front drive shaft, which changed its caster setting from the stock 4.2 degrees to about 3 deg.

The folks in-the-know in the Jeep Mod community recommend that a lifted Jeep should have a caster of somewhere between 5-7 degrees.  To adjust this setting you have to lengthen the front Lower control arm or shorten the upper arm.  The Wrangler has a fixed length LCA, so I bought a set of TeraFlex Lower Control Arms from Northridge 4x4.  

The project is fairly straightforward.  There's 2 nut/bolts that need to be removed from each side.  The tires do not need to be removed.

Stock LCA w/Nut

The nuts are very tight.  I needed a breaker bar and a good ratchet to remove them.  You can also use an impact wrench.

Most write-ups seem to start with the passenger side, but I don't think it matters much.  The key is to do one side at a time.

After removing one of the LCA's the next step is to figure out what TF LCA goes on which side and to set the length.  Laying the stock LCA just removed next to the TF bars helps orientate them. When installed, the TeraFlex logo is right side up and closer to the rear of the bar.

After figuring out what bar will be replacing the one you removed, you need to set the length.  Most folks recommend 3/8" longer than stock, which is 23" eye-to-eye.  23" will yield about a 5.5-6 degree caster on most mildly lifted Wrangler's.  

Installation is the reverse of removal.  I installed the rear end of the bar first, slipped the bolt through (do not install nut) and then I put in the front.  I found that putting some weight back on the tire helped align the holes. 

It's important to leave the nuts and bolts lose until you are happy with the final adjustments and the weight of the Jeep is on its tires.  The bolts need to be torqued at 125 Ft Lbs.  This is a lot more torque than one would think.  It is critical that you do not skip this step.  Lose suspension components lead to the notorious death wobble.

After getting it back together I have about 6 degrees of caster.  I'm going to drive it awhile letting the suspension settle in and check it again. If necessary, I can increase the angle by lengthening the bar (turning the ball to the left).  Or decrease the angle by shortening the bar (turning the ball to the right). 

The final step is to tighten the Jam Nuts and to re-torque all bolts to 125 Ft. Lbs.  Then grease all fittings with a high-quality grease. 

No comments:

Post a Comment