notatoy

ok...so dealer's not going to help on this one so my question is...can I replace these myself? Anyone know of a thread that may help me to do it? Special tools or anything...

wayoflife

radius arms are great on vehicles like desert race trucks where you have big vertical travel of the axle. however, by it's design, radius arms are in a state of bind the moment you try to force them to articulate. if you were to disconnect the radius arms at the frame, they would stand straight out like a diving board. in fact, if you were to grab each end of the radius arms and try to push them in opposite directions, you would find it very difficult to do as your axle holds them firmly in place. think of your sway bar - not the links but the actual sway bar itself - it is basically a torsion bar that wraps around with 2 arms that the links are attached to. that's essentially what your front axle and radius arms are like only, your axle is no torsion bar and it will not twist. there are companies that have made axles that allow for this kind of rotation but without it, you have bind.

now, having said all that, radius arms obviously allow your jeep to flex but in order to do so, an enormous amount of stress is placed into your bushings as they get squashed and stretch. up front, this isn't as much of a problem as the bushings that take the most abuse are the factory ones on top of the axle mounts. these bushings are relatively large, made out of bonded rubber and durable enough to withstand the bind it see for a longer period of time. this is the reason why you don't hear of too many people with TJ's complaining about their radius arms as they only had them up front. in time, these bushings will fail as well but, it takes longer to get there. the problem with the rear radius arms is that the aftermarket bushings used are on the small side of things and, in addition to the stresses they see from flexing, they also sees a lot of stress from axle torque. as you accelerate, your rear axle will want to rotate and the only thing keeping it from doing so is the upper link of your radius arm and its bushing on the axle mount. maybe if the bushing were a lot bigger and made to endure more stress, a radius arm in the rear could be made to work but, i'd take a 4-link setup any day over it.

wayoflife

yes, you can replace them yourself. you will need to pull the radius arm and press the bushing out. i have seen some people beat the bushing with a BFH and i suppose you could do that as well. once the trashed bushing is out, you just need to press the new one in. unfortunately, i can guarantee you that you will blow out the new set as well and in as little as one run - i have seen it happen.

notatoy

RE sent me set of new bushings under warranty. I bought a press from hf. any tips on how and what order to do this? do i jack the frame up?

WKD_YJ

I was watching Extreme 4x4 last week and saw that they installed a radius arm lift on a JK. What are the Pros and Cons of a long arm Radius lift vs a 4 link long arm.

OffRoadGeorge

WoL thank you for this explanation!! I have similar radius arms and now understand the binding. No one ever made it so clear!