[flatlander757]

Originally Posted by triker

Just seems to be the LCA bushings that are dry rotted. And here are the alignment specs left caster is 6 9/16 deg , right caster is 6 5/16 deg , left front camber is -1/2 deg , right front camber is 1/8 deg , left front toe is 5/16" , right front toe is -1/32" , total toe is 9/32" , left rear camber is -19/32 deg , right rear camber is -9/32 deg , left rear toe is 3/32" , right rear toe is 1/8" , and thrust angle is -1/32 deg

Why are those measurements in fractions? Is your alignment shop using tape measures and trigonometry to figure out your alignment specs? That toe reading is what needs to be in degrees, if you have a total toe difference of 9/32" from the front to the back of your tire, it's about 7-8/32" too much. I'd estimate that to be over 1.0 full degrees of total toe

If your front caster is indeed higher on the left side vs right side, that would make it pull right if anything. So that definitely means a bad bushing more than likely.

If you have a clusterfunk of toe like I think you do then I'd say correct that first because having a ton of toe on a solid front axle vehicle can cause some strange handling quirks(pulling one way or the other based on road surface angles/dips and whatnot). It doesn't cause a pull by itself, but the fact that road surface isn't consistant will dictate how much of a negative effect it has on handling.

Originally Posted by CCJ

Flatlander, I was under the impression that when upgrading past a 31" tire... Say a 33 that you need to have toe slightly less then factory spec. (IE: +9 per tire = combined +18 rather then +30 like factory spec calls for) Is this true?

Originally Posted by Unlimited04

wow great thread, nice job flatlander. thanks a bunch.

I just read the whole thing, but i'm still confused on some things.

I'm installing a 2.5" OME soon:
1. Caster will be off a little, but I can't afford adjustable UCA's right now, so theres nothing I can do.
2. my front tires are cupping, so i've already got excessive toe in.
3. when doing a DIY alignment to set the toe in after the lift, what do I use to measure in 1/32nd of an inch? I can't imagine a tape measure is accurate enough, or is it? I read the write up on 4x4xplor, but I've seen another method using rods attached to the wheels to measure toe. Any comments about this?

When you measure the toe front to back using either the tire as on 4x4xplor, or the tube/rod method, what type of difference should I be looking for front to back? Is a tape measure actually accurate enough for this?

Another question - is there any benefits/negatives to running excessive caster with larger tires? like 7* with 35s? or 7* with 33s? (Ignoring pinion angle) Will this make the jeep more stable on the highway, or any other benefits/negatives?

As far as toe goes I can't say but I'd stick to factory specs if you're going by degrees on an alignment machine.

If you're using a tape measure(which IS accurate enough in my opinion) THEN you need to go for a slightly closer tolerance(more towards 1/32" difference vs 1/16" difference front to back of the front tires) due to the fact that the tire surfaces where you're comparing distances to are further from the wheel center. (Go back through the thread, this was covered elsewhere, somebody actually figured out the formula as to what the numbers need to be).

I believe Mr. Blaine and Jerry B. are the ones who pull the tires and mount square tubing to the wheel mounting surfaces for more accurate measurements.

FWIW I do mine on the tire centerline with jackstands placed under the axle so the tires are off the ground(no rubber "deflection" from turning/adjusting on pavement where the tires don't want to move). I'll do it a few times from a few different points(ie: spin the wheels and measure again front and rear) to ensure it's not off far from a not-so straight tire. Obviously I'd make sure your rims aren't bent before you do it this way.

BTW these are Jeeps, no econocars, you NEED to rotate tires religiously or you'll get cupping pretty much no matter what. If I let my Swampers go more than 5000 miles they'd start to show signs of wearing on the leading edge of the lugs. I did it every 3000 miles except for once with no issues.

As for your lift, you *should* be okay, as you lift the Jeep caster decreases so on 33s you might be alright. 35s would be borderline/necessitate adjustable UCAs I would imagine.

Read my section on caster again, too much caster for a given tire size(like 7 degrees on 35s possibly 33s) basically has the steering axis/caster angle laid back so far that when you turn you're trying to flop the rim over but the tire wants to stay put. For an extreme example imagine a 90 degree caster angle. Shake the wheel left and right and you'll just be moving the rims inside the tire as the sidewall flexes. It will be less prominent/important w/ less sidewall. This is why Mercedes and Chrysler 300s and Dodge Chargers and a lot of BMWs can get away w/ 10+ degrees of caster on a 22" size wheel inside a 17-18in rim(pulling numbers out of my ***, but you know what I mean).

Sorry about missing your post, not as much useful info in the TJ tech section when I'm swapping in a 1 ton drivetrain.



I'll more than likely be aiming for around 3-4 degrees of caster for 40" tires w/ 17" rims then go from there.

[CCJ]

Thanks Flatlander.

[Unlimited04]

thanks flatlander. i found out that cupping thing the hard way

your help has been very informative

[greendot200200]

Nice thread

[Eldage]

First let me say this is a GREAT thread. Thank you so much for all the good info.

My question is: Can incorrect toe-in cause death-wobble?

My story:
I bought a 2006 Rubicon Unlimited a couple weeks ago. It only had 6,700 miles on it. I flew down to Tallahassee, FL to pick it up. I drove it over 500 miles back to Memphis, TN. No problems.
This past weekend I upgraded the steering to a Currie Correctlync® HD Steering System. I also ordered a new Steering Stabilizer for it but it has NOT ARRIVED YET.
This morning I was going to drive it to work and before I got out of the neighborhood the front end started to wobble like the front end was COMING APART. I stopped, did a u-turn and slowly drove back to my house with no problem.

I read this entire thread and I think I understand what I need to check:
1) All steering joints to make sure they are tight and torqued properly.
2) Tires balanced (not likely the cause since I didn't have the problem before the steering system upgrade)
3) Check alignment

My question is about this last item. In this thread it seems that most death-wobbles are associated with "caster" and not "toe in".
Since the symptoms only appeared after I performed the steering upgrade I can only assume that:
1) The toe-in is not properly set since this is the only thing I could have changed. (Right?)

OR

2) I already had a problem before the steering upgrade but it is only now appearing because I have no steering stabilizer installed.

So my question is: Is it possible for incorrect toe-in to cause death wobble?

[CB3]

Hi Flatlander. I greatly appreciate this thread, and also thanks to Mr Blaine and Jerry and others.

2006 LJ Rubicon with 21K miles on it. I have an approx 3" actual lift (OME 2.5" spring + OME 0.39" spring leveler pad). I have American Racing 15 X 8 rims with 4.5 BS and 33 X 10.5 R15 BFG AT with about 10K or 11K miles on them.

I also have JKS length adjustable LCAs and stock UCA.

According to my local 4X4 shop, I have 7 degrees castor. I haven't noticed any problems with that (AFAIK), except that my Riddler front diff cover is darn close to my front trackbar and a slight scraping/rubbing occurs between the two on hard bumps with full suspension compression. Other than that, I'm not aware of any problems with 7 degree castor.

However, in keeping with your recommendations, I'm planning to have my castor adjusted to 6 degrees, which will also move my front axles and front diff cover back a little bit, hopefully eliminating the slight rub between the front diff cover and front trackbar. I'm also getting a Crane cover that allegedly (according to Crane) will give me a little more trackbar clearance than the Riddler, but even so, I want to change my castor to 6 degrees because you said that's better with 33" tires, and I might as well gain some diff cover to trackbar clearance too.

I'm not very confident in my local 4X4 shop's alignment abilities. Luckily a friend of mine is now back at an alignment shop after returning from retirement. He has experience aligning Nascars and other competitive racecars, and I remember that he used to align my XJ better than any other place I've ever been. He also has a fair amount of 4X4 alignment experience since this is a redneck area. (any local rednecks would be proud of that, so I wouldn't be offending them by saying it).

So I am now hopeful of getting a quality alignment. Just in time too, because I'm sure I have alignment issues because: 1) my rolling resistance seems extremely high to me. I cannot push my LJ even an inch, while I used to be able to push my XJ easily. 2) I think my gas mileage should or could be better. 3) My front tires are wearing much more rapidly than my rear, and it is NOT even wear. The outer half of the front tires is getting all the wear. The inner half still has the nipples on it. This after 10K miles. Also, I'm sure I'm due for a tire rotation and balance check, but I'll let the alignment guy do that at the time of alignment so he can see the tire wear.

=====

Before going to the alignment shop, I'd like to have a list of specs for him to aim at. Based on reading this thread, this is what I think (if I understand) should be my desired alignment specs: (Please verify if I'm thinking correctly)

1) Castor 6 degrees (33 X 10.5 tires on 15 X 8 rims with 4.5 BS and 3" lift). I read your reasons for that. 7 seems to work fine for me, except diff cover hitting track bar (adjustable LCA and stock UCA). So I want to move the bottom half of the diff cover backwards a bit for clearance reasons anyway.

I think that 6 degree castor would accomplish that, and maybe drive better too since I have 33" tires and 3" lift.

Though it seems to drive good now, except for an annoying pull to the right and front tires rapidly wearing on outer edges. No, this Jeep has never been jumped in the desert. I've owned it since brand new and babied it (while babying my bad back - definitely no jumping).

2) Toe - he'll be setting that probably with a machine that uses degrees. If in degrees, how many degrees should it be? I assume whatever degrees is stock. If in inches, then 1/32"? I read there is a formula somewhere in the thread for calculating toe inches, but I can't find the formula.

3) All other alignment settings stock? I found your listing of stock alignment settings for your 2003 Wrangler. Are the stock settings the same for my 2006 Wrangler Rubi Unlimited?

Also, I'm considering getting adjustable ball joint(s) so my camber can be adjusted. If I do that, what camber would be best? or is that something an alignment guy has to figure out on a case by case basis?

[mudb8]

moving to 6 dergrees will put the diff cover closer to the track bar, not farther away, to get to 6 from 7, the pinion has to get tilted up....

I actually set em to close to 7 if the tires are 33" and smaller, and use factory specs on camber... they drive and handle great..

heres one I did on friday... since this thread lacks real world pics and I do alot of jeep alignments, I'll make my contribution.. on how we do this stuff..

It belongs to the daughter of Warn's CEO, the skyjacker track bar, 4" lift, had been hammering the diff cover and needed the heim replaced the caster was at 2.9 degrees.. the upper arms had to be shortened to get it into spec. you'll notice the camber is off 1 degree on both sides.. they opted to leave it be. the track bar still hits...

the tire was well centered In the wheel well so messing with the lower arms was outta the question,.. the uppers had to get shortened because they don't adjust in enough.





notice the chain? it was to pull the pinion down so I could get the bolt in the axle end. didn't have it in me even with a 4' bar to tip it



finally after both arms are done...



cam bolts can also be used on the front lower arms for caster adjustments... and minor pinion adjustments in the rear upper arms... doing the rear is about the most PITA job there is if you don't have the punch to stamp out the holes..




heres a 1.5 degree joint installed to fix a camber issue

[flatlander757]

Originally Posted by CB3

Hi Flatlander. I greatly appreciate this thread, and also thanks to Mr Blaine and Jerry and others.

2006 LJ Rubicon with 21K miles on it. I have an approx 3" actual lift (OME 2.5" spring + OME 0.39" spring leveler pad). I have American Racing 15 X 8 rims with 4.5 BS and 33 X 10.5 R15 BFG AT with about 10K or 11K miles on them.

I also have JKS length adjustable LCAs and stock UCA.

According to my local 4X4 shop, I have 7 degrees castor. I haven't noticed any problems with that (AFAIK), except that my Riddler front diff cover is darn close to my front trackbar and a slight scraping/rubbing occurs between the two on hard bumps with full suspension compression. Other than that, I'm not aware of any problems with 7 degree castor.

However, in keeping with your recommendations, I'm planning to have my castor adjusted to 6 degrees, which will also move my front axles and front diff cover back a little bit, hopefully eliminating the slight rub between the front diff cover and front trackbar. I'm also getting a Crane cover that allegedly (according to Crane) will give me a little more trackbar clearance than the Riddler, but even so, I want to change my castor to 6 degrees because you said that's better with 33" tires, and I might as well gain some diff cover to trackbar clearance too.

Going from 7 degrees to 6 degrees will tilt the top of the axle forward... so if anything it will make your rubbing worse AFAIK. You can shorter the LCAs some for lowering caster while helping clearance at the diff cover.

I'm not very confident in my local 4X4 shop's alignment abilities. Luckily a friend of mine is now back at an alignment shop after returning from retirement. He has experience aligning Nascars and other competitive racecars, and I remember that he used to align my XJ better than any other place I've ever been. He also has a fair amount of 4X4 alignment experience since this is a redneck area. (any local rednecks would be proud of that, so I wouldn't be offending them by saying it).

So I am now hopeful of getting a quality alignment. Just in time too, because I'm sure I have alignment issues because: 1) my rolling resistance seems extremely high to me. I cannot push my LJ even an inch, while I used to be able to push my XJ easily. 2) I think my gas mileage should or could be better. 3) My front tires are wearing much more rapidly than my rear, and it is NOT even wear. The outer half of the front tires is getting all the wear. The inner half still has the nipples on it. This after 10K miles. Also, I'm sure I'm due for a tire rotation and balance check, but I'll let the alignment guy do that at the time of alignment so he can see the tire wear.

I'd say you just have a toe problem. It will wear part of the tire unevenly and if it's kinda far out it will cause excessive rolling resistance too. Have you jacked the wheels off the ground to make sure it isn't anything driveline related causing the resistance? I'd do that just for some peace of mind, but due to your tires wearing fast I'll bet on toe.

=====

Before going to the alignment shop, I'd like to have a list of specs for him to aim at. Based on reading this thread, this is what I think (if I understand) should be my desired alignment specs: (Please verify if I'm thinking correctly)

1) Castor 6 degrees (33 X 10.5 tires on 15 X 8 rims with 4.5 BS and 3" lift). I read your reasons for that. 7 seems to work fine for me, except diff cover hitting track bar (adjustable LCA and stock UCA). So I want to move the bottom half of the diff cover backwards a bit for clearance reasons anyway.

I think that 6 degree castor would accomplish that, and maybe drive better too since I have 33" tires and 3" lift.

Normally caster is lessened by adjusting the UCA, your wheelbase may be noticably shorter when the lowers are adjusted to get the same angle since the LCA mounts are closer to axle centerline, thus they have less effect on caster when adjusted the same distance in relation to a UCA.

Though it seems to drive good now, except for an annoying pull to the right and front tires rapidly wearing on outer edges. No, this Jeep has never been jumped in the desert. I've owned it since brand new and babied it (while babying my bad back - definitely no jumping).

If it's pulling check for the calipers dragging and all that good stuff first, then rotate the front tires left to right and see if the pull either changes or goes away. If it stay in the center lane of the highway for a little while I'd say it isn't actually a pull, just road crown and your Jeep is a bit more sensitive to it due to the tires. Mine would drift to the right in the right lanes, left in the left lanes, and stay fairly straight in the center lanes.

2) Toe - he'll be setting that probably with a machine that uses degrees. If in degrees, how many degrees should it be? I assume whatever degrees is stock. If in inches, then 1/32"? I read there is a formula somewhere in the thread for calculating toe inches, but I can't find the formula.

If it's getting done on a machine have him set it to the factory spec. It was posted somewhere on the first page and should be highlighted IIRC. You only use inches to set toe yourself at home w/ a tape measure. Very easy to do and I'll recommend you do that yourself first. Read the write-up on www.4x4xplor.com or www.stu-offroad.com

3) All other alignment settings stock? I found your listing of stock alignment settings for your 2003 Wrangler. Are the stock settings the same for my 2006 Wrangler Rubi Unlimited?

I honestly don't know, you'll have to find that for yourself, if I remember to look on Monday, I'll check the alignment computer at work to see if there are different specs for a TJ vs LJ. I do know that there is no difference between any other TJ and Rubicon TJ of the same year. There MIGHT be tiny differences between years but for the most part it's unimportant.

Also, I'm considering getting adjustable ball joint(s) so my camber can be adjusted. If I do that, what camber would be best? or is that something an alignment guy has to figure out on a case by case basis?

Camber is supposed to be around 0.0. Unless it's far out of spec I wouldn't bother with it. Camber can be relatively far out of spec(maybe +/- 1.0 full degrees) with no ill effects. Uneven tire wear will be minimal if not non-existant because you SHOULD be rotating your tires every 3k to 6k miles anyways and it normally doesn't cause a pull except in extreme cases. Hell a lot of German cars run pretty crazy camber without tire wear problems. I did an M3 that had a spec of like 3.0 degrees of negative camber in the rear, I can't recall what the front was to be set at.

Honestly I'd say set your toe w/ a tape measure and you should be okay, but if you really want your caster adjusted accurately then go for an alignment and set it to 6.0 degrees. I myself am a cheap bastard so I'd toe it myself and let it eat unless I had problems after that.

Oh and ROTATE YOUR TIRES!

[mudb8]

Originally Posted by flatlander757

Honestly I'd say set your toe w/ a tape measure and you should be okay, but if you really want your caster adjusted accurately then go for an alignment and set it to 6.0 degrees. I myself am a cheap bastard so I'd toe it myself and let it eat unless I had problems after that.

Oh and ROTATE YOUR TIRES!

sound like me!

[pbj-tj]

What a great thread!

Excellent write up man

[flatlander757]

Originally Posted by pbj-tj

What a great thread!

Excellent write up man

Thanks





For those interested here is my high tech alignment machine:





For my 1 ton build I'm setting caster at 7 degrees as that is what I found works for most others on 40s w/ stretched wheelbase and whatnot. All my control arms are adjustable so if that doesn't work out I'll still be okay.

[CB3]

Thanks Flatlander and Mudb8.

I have another couple important questions though.

One or both of you said that castor is normally adjusted by changing the length of the UCAs, not the LCAs. You said that shortening LCAs to decrease castor from 7 to 6 would substantially move axle rearward.

Wouldn't that also work the other way around? So lengthening LCAs to increase castor from 6 to 7 would substantially move axle forward. Correct? I think that is what my local 4X4 shop did that caused the clearance problem.

My local 4X4 shop set the castor to 7 degrees at my request when they installed the lift and JKS adjustable length LCAs. I asked them to make the castor whatever is stock castor (7 degrees) because I wanted a stock ride. It has worked well for giving a stock ride and steering feel, but I did not forsee the front diff cover hitting/rubbing trackbar.

Earlier I thought the trackbar clearance issue was solved by switching from an ARB diff cover to a Riddler. The Riddler improved the clearance, but did NOT solve it. The Riddler occasionally rubs slightly on hard bumps.

Here's the thing. With the lift and 33 inch tires my castor would have been less than 7 degrees (around 6 I think) if I had stock control arms. I think the 4X4 shop adjusted the JKS adjustable LCAs longer than stock LCA length to get 7 degree castor. The UCAs are stock and not adjustable. They changed my castor to 7 soley by lengthening the LCAs. [B]Wouldn't that mean their lengthening my LCAs moved my front axle substantially forward? I suspect this might be a factor in my clearance problem.

Considering the past history that got me here (UCAs are stock - LCAs are adjustable and were previously lengthened) wouldn't the cure for clearance be to shorten my LCAs to something closer to stock length? If so, wouldn't that also give me approx 6 degrees castor?

i.e. - I think have to undo what my local 4X4 shop did that caused the clearance problem. It seems logical that their possible over-lengthening of my LCAs must be a root cause of the clearance problem since my UCAs are stock and non-adjustable. So in turn, it seems the way to fix this is to shorten the LCAs back up a bit. Ideally to 6 degrees castor, if that woudn't be to short an LCA.

Didn't you (Flatlander) say earlier that with a 3" lift and 33" tires and stock UCA and stock LCA, a guy would have around 6 degrees castor and that's ideal? If so, why can't I shorten my LCA to be stock length or near stock length ? Thus reversing what 4x4 shop did when they lengthened them, and getting me more diff cover to trackbar clearance and approx 6 degrees castor?

While I understand that you said changing the UCAs length is the typical way to adjust castor, I can't do that with stock UCA. Also, I think my clearance problems started with my local 4X4 shop lengthening my LCAs. Though my aftermarket diff cover is also bigger than stock. ARB cover stuck out way more than stock cover, Riddler and Crane stick out somewhat more than stock. Perhaps I'll have to find a more modest front diff cover that doesn't stick out as much.

Just out of curiosity, what how long are the stock LCAs? I'd like to know because that would give me a basis of comparison to then current length of my JKS LCAs, which might help me figure out the length they should be.

[numchuck]

Tony, man, you get a "gold star".

[mudb8]

Originally Posted by CB3

Just out of curiosity, what how long are the stock LCAs? I'd like to know because that would give me a basis of comparison to then current length of my JKS LCAs, which might help me figure out the length they should be.

we can adjust both, tho using stock ca's, cam bolts are used to adjust the caster with the lower arm.. to put your caster to 6 you need to shorten the jks arm... stock lower arms are 15 3/4", the front uppers are 15". most aftermarket fixed lower arms are 16", aftermarket adjustable uppers adjust down to 15.5" and fixed aftermarket upper arms are also 15.5" .
it's a resonable assumption that shortening the jks lowers will help with the track bar rub, depending on the track bar.

the reason for adjusting the uppers instead of the lowers is it reduces the amount of wheel base change...

what adjustable track bar are you running?... post a pic in the track bar thread of the rub if you can.

[flatlander757]

Originally Posted by CB3

Thanks Flatlander and Mudb8.

I have another couple important questions though.

One or both of you said that castor is normally adjusted by changing the length of the UCAs, not the LCAs. You said that shortening LCAs to decrease castor from 7 to 6 would substantially move axle rearward.

Wouldn't that also work the other way around? So lengthening LCAs to increase castor from 6 to 7 would substantially move axle forward. Correct? I think that is what my local 4X4 shop did that caused the clearance problem.

My local 4X4 shop set the castor to 7 degrees at my request when they installed the lift and JKS adjustable length LCAs. I asked them to make the castor whatever is stock castor (7 degrees) because I wanted a stock ride. It has worked well for giving a stock ride and steering feel, but I did not forsee the front diff cover hitting/rubbing trackbar.

Earlier I thought the trackbar clearance issue was solved by switching from an ARB diff cover to a Riddler. The Riddler improved the clearance, but did NOT solve it. The Riddler occasionally rubs slightly on hard bumps.

Here's the thing. With the lift and 33 inch tires my castor would have been less than 7 degrees (around 6 I think) if I had stock control arms. I think the 4X4 shop adjusted the JKS adjustable LCAs longer than stock LCA length to get 7 degree castor. The UCAs are stock and not adjustable. They changed my castor to 7 soley by lengthening the LCAs. [B]Wouldn't that mean their lengthening my LCAs moved my front axle substantially forward? I suspect this might be a factor in my clearance problem.

Considering the past history that got me here (UCAs are stock - LCAs are adjustable and were previously lengthened) wouldn't the cure for clearance be to shorten my LCAs to something closer to stock length? If so, wouldn't that also give me approx 6 degrees castor?

i.e. - I think have to undo what my local 4X4 shop did that caused the clearance problem. It seems logical that their possible over-lengthening of my LCAs must be a root cause of the clearance problem since my UCAs are stock and non-adjustable. So in turn, it seems the way to fix this is to shorten the LCAs back up a bit. Ideally to 6 degrees castor, if that woudn't be to short an LCA.

Didn't you (Flatlander) say earlier that with a 3" lift and 33" tires and stock UCA and stock LCA, a guy would have around 6 degrees castor and that's ideal? If so, why can't I shorten my LCA to be stock length or near stock length ? Thus reversing what 4x4 shop did when they lengthened them, and getting me more diff cover to trackbar clearance and approx 6 degrees castor?

While I understand that you said changing the UCAs length is the typical way to adjust castor, I can't do that with stock UCA. Also, I think my clearance problems started with my local 4X4 shop lengthening my LCAs. Though my aftermarket diff cover is also bigger than stock. ARB cover stuck out way more than stock cover, Riddler and Crane stick out somewhat more than stock. Perhaps I'll have to find a more modest front diff cover that doesn't stick out as much.

Just out of curiosity, what how long are the stock LCAs? I'd like to know because that would give me a basis of comparison to then current length of my JKS LCAs, which might help me figure out the length they should be.

You should shorten the LCAs... halfway through the last post I realized you said you had adjustable LCAs, the first 2 reply/quotes I was thinking you had adjustable UCAs. Definitely shorten the LCAs to stock length(mudb8 says 15.75" so start there).

Frankly on TJs you don't need an alignment machine for anything. Caster can be set w/ an angle finder(provided you have a known level floor and have torn down the knuckle to measure the angle between the balljoints), then camber obviously can't be easily changed, you can do that by eye. If it looks straight up and down you're good to go. Then toe is set w/ a tape measure. Usually 1/32" to 1/16" toe in.

Originally Posted by numchuck

Tony, man, you get a "gold star".

Thanks dude

Where can I pick up said gold star?

Originally Posted by mudb8

we can adjust both, tho using stock ca's, cam bolts are used to adjust the caster with the lower arm.. to put your caster to 6 you need to shorten the jks arm... stock lower arms are 15 3/4", the front uppers are 15". most aftermarket fixed lower arms are 16", aftermarket adjustable uppers adjust down to 15.5" and fixed aftermarket upper arms are also 15.5" .
it's a resonable assumption that shortening the jks lowers will help with the track bar rub, depending on the track bar.

the reason for adjusting the uppers instead of the lowers is it reduces the amount of wheel base change...

what adjustable track bar are you running?... post a pic in the track bar thread of the rub if you can.

Good info, thanks dude