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WJ Upper Control Arms on an XJ?

comanche91

NAXJA Forum User
I installed WJ lower control arms on my MJ awhile back and I really like the improvement in handling. I'd also like to try the WJ uppers too. They are the same eye-to-eye length as the MJ/XJ stock upper arms, but are stouter and a similar bend in them like the WJ lowers. Has anyone tried using the WJ UCAs on an XJ/MJ? Thanks

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they bind on the body-side mounting bracket and prevent the axle from drooping. they won't work without major modification to the arm (cutting half of it off) or the mount

full droop

WJ_UCAs_Mounted_1.sized.jpg


you would have to clear the back to match stock, ie remove half of the arm

UCA_Comparison.sized.jpg


by the time you were done it wouldn't be any better than the XJ/ZJ/TJ UCAs, and probably worse since the WJ arms wouldn't have the double-folded edging
 
"by the time you were done it wouldn't be any better than the XJ/ZJ/TJ UCAs, and probably worse since the WJ arms wouldn't have the double-folded edging"

Yep, I can see that now. There goes another not-so-bright idea. Thanks for a great reply by ehall. -Don
 
At least on an MJ, you do not have to cut the arm... You have to trim a small piece of sheet metal directly below the bucket for clearance...
 
Got em installed...

I've got to say this upgrade has made a significant improvement in the way the truck steers and handles on the road. The is no more play in the steering wheel before the steering reacts, it is instantaneous (original steering box). Just minute movements of the wheel and it reacts. The whole front end has firmed up significantly, in a good way. Cornering body lean is reduced even further. Awesome upgrade. :rock on: On to the Pics:

IMG_0181.jpg


Here is a pic comparing the stock arm with the WJ arm, notice the WJ arm is fully boxed. The stock arms measures 15" eye to eye, the WJ arm measures about 14.9". This corrects my caster with my 2" lift over stock, rather than adding spacers to the LCA buckets.

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Picture of drivers side upper control arm bucket.

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Remove this small amount of sheet metal directly below the bucket. (Cut a mirror image off the passenger side, I used a dremel with reinforced quick connecting cutting wheel)

IMG_0193.jpg


Size reference.

Thats it, then install the WJ arms. I used a pipe wrench with my jack to help line up the axle side bolts, but a come-along will work too. Do them one at a time.

More pics:

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Full Droop, no problems.

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:chillin:
 
The pics I took are at full droop, wheels off. At full droop they do contact slightly (scuffs the paint off, but no structural damage). But the WJ Lower arms are contacting the axle side shock mount at this point too. The upper arm is not the limiting factor here.

A slight grinding of the (talking half a millimeter here) top edge of the upper bucket lower lip would clear it. But again the front tops of the lower arm are already contacting the axle side shock mount.

:cheers:
 
Last edited:
Wanted to bring this up to the top:

Anybody know if this would work with drop brackets? I would guess that it should, especially since I wouldn't have to trim that piece like he did.
 
I'll bump this as well since I'm putting the pieces together to rebuild the front end of my wifes XJ. Since 1988MJ was able to do this on his MJ will this also work on an XJ? Seems like a pretty easy modification to add a stronger upper control arm. My other thought has been to simply box the uppers on the XJ by welding a strip of metal on the "open" lower side of the control arm.
 
I'm planning on installing drop brackets and lower & upper WJ control arms on my 01 XJ. Have all the parts just need a good day off to make it happen. Just holding the WJ control arms the weight difference tells you they are much stronger than xj ones.
 
I'll bump this as well since I'm putting the pieces together to rebuild the front end of my wifes XJ. Since 1988MJ was able to do this on his MJ will this also work on an XJ? Seems like a pretty easy modification to add a stronger upper control arm. My other thought has been to simply box the uppers on the XJ by welding a strip of metal on the "open" lower side of the control arm.


That may owrk well too, but I would think that welding to that piece may actually weaken it. I am pretty sure those parts are cold stamped,a nd by adding heat you may weaken the arm more so than strengthening it.. I am not positive, and I really like the idea..
 
Being a muscle car guy who has restored several GM "A" bodies, this is actually a trick that is pretty common. These cars have coil spring rear suspensions with upper and lower control arms that are U shaped. And the first thing we would do to strengthen the arms was to box them. In fact, early seventies cars with big block motors and 12 bolt rear ends had their control arms boxed by the parts manufacturer. Which is where I got the idea.
 
I'll bump this as well since I'm putting the pieces together to rebuild the front end of my wifes XJ. Since 1988MJ was able to do this on his MJ will this also work on an XJ? Seems like a pretty easy modification to add a stronger upper control arm. My other thought has been to simply box the uppers on the XJ by welding a strip of metal on the "open" lower side of the control arm.
... did you read the thread? It's possible with minor mods on an MJ, not possible without more extensive mods and/or weakening on an XJ.

I'm planning on installing drop brackets and lower & upper WJ control arms on my 01 XJ. Have all the parts just need a good day off to make it happen. Just holding the WJ control arms the weight difference tells you they are much stronger than xj ones.
Read the thread...

Wanted to bring this up to the top:

Anybody know if this would work with drop brackets? I would guess that it should, especially since I wouldn't have to trim that piece like he did.
Might, from what I can see on the RC drop bracket kit, there is LOTS of clearance all around the UCA mounts. Not sure if the RE/other kits are the same.
 
... did you read the thread? It's possible with minor mods on an MJ, not possible without more extensive mods and/or weakening on an XJ.
Look at the pics, the MJ and XJ setups are identical. The MJ axle droop is limited in the same way (the arm is making contact according to the poster) but he is willing to live with it. The arm did not droop enough on my lifted XJ for me to feel comfortable with it. That's the difference.
 
My opinion is that I'd do the WJ arms for a 2" BB or less. I don't think boxing the stock arms would be worth the work--it's certainly doable with a hand-held metal brake and some spot welds, but you can buy aftermarket arms that are much stronger for not much coin.
 
Just installed the WJ upper and lower control arms with RE drop brackets. The bushing sleeves on the lower control arms had to be grinded down flush with the arm to fit without problems. I used a table grinder for this and minus the smell of burning bushing wasn't any trouble. I'm sitting on just 3 stock spring bushings and ZJ springs for 2" BB. RE drop brackets lower the control arms 3"s so my arms are pointing slightly upward for now. I have RE 3.5 springs waiting for some more time off to be installed. After driving on highway I must say that from the stock control arms w/poly bushings to the WJ rubber bushings highway is much quiter and smoother. Also the handling with the corrected caster and stronger arms was a great plus. I'd recommend it for anyone that has the parts or looking for a cheaper route than aftermarket arms.
 
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