OK, so I 'm hard headed...

but please help me understand this...

I had a recent thread asking about replacing or not replacing the LCA's because of an email reply from a lift supplier (4") who said they were not necessary to replace.

I received a number of very helpful posts that provided some understanding as to why replacement was a good thing, and I thank you all!

Soooo, back to researching kits and now I've got my sights on the RE6130 4.5" that comes with fixed replacement arms and....

Then I read this write-up on that very kit ( http://www.ericsxj.com/stage1.htm ) which shows a picture of the arms and they are basically the same length as the original???

Guys, don't get frustrated with me but the picture of the arms just doesn't add up to what I thought I was understanding and certainly not what I expected to see.
I expected even the fixed arms to have an obvious visual difference in length from the stockers. The ones provided by RE for this kit don't have a dogleg design either.

How are these beneficial, at the same length, in correcting the front end geometry and providing more droop?

I am running 4.5 or 5" of lift and I have adjustable lowers but they are only about an inch longer than the stock ones so its not a huge difference. I think RE would be your best bet for a complete kit or rustys. just my opinion.l

You're not being hard-headed. You're doing research and TRYING to understand.

BUCKYXJ is right in that there is relatively little difference in length necessary as you go up in height.

There are actually 2 functions accomplished with aftermarket arms, though. You've identified the first: length. The second is strength. Aftermarkes are built much stouter.

My personal opinion, and only my opinion: stock control arms to 3", aftermarket lowers only to around 4.5" and replace both uppers and lowers above 4.5". I also run adjustable arms (at least, when they're not frozen up!) to tweak wheelbase with the lowers and set caster with the uppers.

What was that old formula someone came up with. It was something like the sum of original control arm length squared and amount of lift squared. Then divided by something. I don't remember. I'm sure someone does, remind us.
Chadc

Most of the fixed length ones I've seen also have a kink in them to facilitate better flex by not binding up on the shock mounting plate.

Mark

The RE arms are 1/4" longer and dont need the kick because they weld to the bottom of the front bushing.Buy RE fixed lowers and adjustable uppers!!!!

I have cheapo Skyjacker fixed LCA's that came with the 3" kit I got a long time ago, and there is a difference in length, just not much. It doesn't take much, but the difference was enough to get rid of the death wobble I had after I first installed the kit and some additional spacers.

I think there is probably less than 2" difference between stock and an 8" short arm setup for CA lengths....think about it the angles. Your CA's correct wheelbase and caster after lift, it doesnt take much of an adjustment in length to move a degree at the pinion and 6" up doesn't = 6" loss of wheelbase. IMHO get adjustable uppers and lowers and control your own destiny.

P

I've found this thread quite helpful as I'm about to fabricate my own LCA. I currently have 3" of suspension lift and will probably add another 1.5" using various spacing methods.

As this thread has pointed out there are currently quite a few length variations available aftermarket.

Am I correct in saying that with fixed UCAs (I have aftermarket ones from Rusty's), all I'm looking to do with the LCA length is make the caster angle as close to stock as possible?

Thanks,

Matt

Flex arms

"IMHO"!


If you run with your sway connected, then it wont matter much. But discoed, then the bushings will not last long, under flex I have toasted the bushings on 2 axles on 2 XJ's But flex arms, FWIU, have to be rebuilt, or the fall apart. Its a loose, loose situation. Heim, or Johnny.

Flex arms

F-N red "X's"

Screw it

:anon:

I remember reading somewhere in the past about an install of adjustable LCA's by starting out at 1" longer than stock and adjusting as necessary from there (unfortunately don't remember the height of lift). I guess this thought coupled with my imagination of what is taking place during the lift and talk of adjusting the wheelbase made for an expectation of more movement than 1/8" to 1/4". I wish I could see something like an engineering type drawing of the whole set-up. I think a good visual would have helped me get my mind around this better.

One last thought - is the standard adjustable trackbar that comes with the RE6130 4.5" sufficient or would it be wise to upgrade to the heavy duty bar and bracket? (jeepin.com has a good price, free shipping, and DT3000 shocks)

Once again thank you all for sharing your knowledge.

What I know about LCAs is this:

Stockers are about 16", most aftermarket arms are 16.25-16.5"

I ran some custom LCAs that were 17.25" and at 8"-9" lift the tire would get into the front bumper pretty bad. I then added drop brackets & made the situation worse, but the ride was nice.

If you are building your own, there is a simple way to get the length that you need. Support the body on a jackstand & jack up the axle until you get the control arm level/parallel with the frame where the arm mounts (may need to remove the coil to do this). This will be the furthest forward that the axle can move. Measure the tire's position in the fenderwell & you'll know how much to add to your LCA length. Guessing is for weinies.