Odd UCA Question

After a full day of searching through the forums, i have found two people that have replaced the UCA's with only 3" of lift. They both loved it, so, i am thinking of doing this to 1. restore my ability to have a perfectly aligned 2000 XJ, and 2. to have the added ride comfort and articulation. Any thoughts other than two people on the issue? Do i need adjustable or fixed....where is the best price (so far im looking at adjustable RE with shipping $230)

StylerG said:

After a full day of searching through the forums, i have found two people that have replaced the UCA's with only 3" of lift. They both loved it, so, i am thinking of doing this to 1. restore my ability to have a perfectly aligned 2000 XJ, and 2. to have the added ride comfort and articulation. Any thoughts other than two people on the issue? Do i need adjustable or fixed....where is the best price (so far im looking at adjustable RE with shipping $230)

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I am doing this, well, I got as far as buying adjustable RE superflex UCAs, just haven't gotten around to installing them. I plan on sort of going between proper pinion angle so i don't get vibes in 4WD and proper caster angle so I don't get death wobble....neither will be perfect, but I should be able to get it close.

Get the adjustables. That way you can fine-tune the pinion angle (and tweak the alignment a bit) but more importantly when the urge bites you and you want to jump up 2" or so you'll still be able to use your UCAs without having to buy a whole new set.

StylerG said:

After a full day of searching through the forums, i have found two people that have replaced the UCA's with only 3" of lift. They both loved it, so, i am thinking of doing this to 1. restore my ability to have a perfectly aligned 2000 XJ, and 2. to have the added ride comfort and articulation. Any thoughts other than two people on the issue? Do i need adjustable or fixed....where is the best price (so far im looking at adjustable RE with shipping $230)

Click to expand...

Just a thought but your uca's are good to 4.5". Could that $230 be spent elsewhere, say on skids or tow points for example. The RE adjustable uppers are good, but they might be even better by the time you actually NEED them. An alignment should get you within spec with stock uppers. Is your ride that bad?

At only 3" of lift you should be able to dial in your caster with shims on the lower control arm mounts. Im getting a 3" lift together and was researching control arms pretty hard. The only reasons I see to run aftermarket arms at that height is to increase articulation and reduce stress on the control arm mounts by getting arms that articulate. Aftermarket arms are stronger than the factory units also. The drawback is that this also makes them more ridgid so unless you get articulating arms, they wont flex as well as the factory arms and they will increase the stress on the mounts.

The issue he is having I think is that he has a Low Pinion D30, which are more prone to driveshaft vibrations in 4WD due to improper pinion angle, which can only really be adjusted with adjustable control arms...my guess would be he already has aftermarket fixed lowers, so he might as well replace the uppers with adjustable ones...at least that was my reasoning behind it.

I have RE superflex adjustable uppers and fixed lowers and am sitting at about 3", maybe a little less...

With a HP D30, the uppers barely get short enough to work - mine are adjusted almost all the way in. This may not be a problem with the LP front end. Also, the axle is shifted slightly forward with this setup, which has caused some interference with my JKS track bar. I had to modify the front diff cover to deal with this.

I am not sure whether there is an absolute gain in articulation or not, but I suspect that the stress on the mounts is a bit lower when I am really twisted up. I think the new arms transmit a bit more vibration, and they require more maintenance (greasing the ends regularly...). Overall I am happy and would do it again.

Travis