Wandering and Alignment Specs

Hi all,

I recently put in a Fusion 4x4 front axle. In the process, I messed up a bunch of my control arm lengths. The front axle had a different ratio than the rear, so I got it drivable (without the front driveshaft, obviously) and took it to a local 4x4 shop for a regear. I got in a rush to finish assembling and installing the front axle before the appointment, so the control arm lengths got changed to whatever made it convenient to install the suspension. Drove like crap, but I wasn't going far. When I got to the shop, I also had them weld the rear tubes to the pumpkin and perform an alignment. I figured they work on modified off road vehicles all the time and would check things that a more typical alignment shop might not realize to check on a Wrangler (control arm lengths, track bar, etc.). Boy was I wrong!

I knew the control arm lengths were messed up when I took it there, so I'm not blaming the shop for setting them poorly. I am blaming the shop for not checking them or correcting them. The alignment was only marginally better than when I took it in. I suspect they only adjusted the toe and centered the steering wheel. I could feel the passenger tire go up speed bumps before the driver tire. I didn't feel safe driving it over 45 mph.

Later, in my garage with only a measuring tape, angle finder, and a floor jack, I found that the passenger front lower control arm was 0.5" longer than the driver's side. The caster was a whopping 0 degrees (with an aftermarket axle with extra caster correction). The track bar was left in a less-than-optimal mounting location (which I put there mistakenly in my exhaustion the night before).

I got the control arms as good as I could, put the track bar in a better spot (more parallel to the drag link) in my garage. Immediately it felt better, but not great. Still felt flighty, especially over 55 mph.

I then took it to a Goodyear and they did a reasonable job. It's better, but still feels like it wants to wander at speed. They gave me a readout of before/after measurements. The toe was corrected, camber looks good (I have new ball joints, housing, shafts, and unit bearings so it better be good haha).

The caster is 2.99* driver and 2.85* passenger. I want to make this better, but I'm at the shortest length on my upper control arms. I supposed I could extend the lowers. I set them to about 23 1/8" (synergy suggests 23 1/4", so maybe I have some slack there).

I also noticed that the camber on the passenger rear is -0.5* (driver is -0.09*). Is this concerning? Could the welder at the first shop have warped the tube by welding at the pumpkin? Would I notice this while driving?

The thrust is 0.07*. Would this be noticeable while driving? This would be adjusted by making sure the control arms are symmetric driver/passenger, right? In other words, make sure the front and rear axles are parallel to each other and perpendicular to forward motion.

Side note, how much should I expect an alignment cover? Was I being unreasonable expecting the control arms to be addressed? The track bar probably wouldn't be addressed, I'll own that one.

Thanks for reading the long post and for any feedback!
 

WJCO

Meme King
A lot going on here. Most alignment shops are ignorant with 4x4 vehicles and aftermarket stuff. Not surprising they didn't touch the caster/control arms.

Your caster needs to be corrected. If you can, make the lowers longer but make sure that your bump stops still hit. Also, make sure both are the same length.

What's your tire pressure at?

Lastly, the rear camber...Was this on their printout or you verified it yourself?
 

A.J.

Active Member
You will need to lengthen your lower control arms. I just went through this with my Fusion D60 axles as well. They set them up for basically stock length uppers and adjust caster/pinion angle with the lowers. I ended up at 7deg caster and 3deg pinion. I am running Synergy control arms. Front uppers 18 1/2" Front lowers 23 3/4" this is with 4" EVO plush ride springs and 3" bump stops. Every set up varies a little but this should be fairly close. As WJCO said just make sure they are even.


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Lojo

New member
A lot going on here. Most alignment shops are ignorant with 4x4 vehicles and aftermarket stuff. Not surprising they didn't touch the caster/control arms.

Your caster needs to be corrected. If you can, make the lowers longer but make sure that your bump stops still hit. Also, make sure both are the same length.

What's your tire pressure at?

Lastly, the rear camber...Was this on their printout or you verified it yourself?

Quick question? You mentioned to make sure they are the same length? My passenger side is about 1/2 inch longer. I’m 5.5 Driver’s and 5.8 passenger with caster. Stock uppers and adj lowers. How important is it and what could happen? Thanks


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Thanks for the replies.

I checked my tire pressure. Most tires were in the 38-40 psi range. I dropped them all to 36-37 psi. They are old, stock sized tires with an odd wear pattern, so they very well could be a major contributor.

I will lengthen the lowers and make them symmetric. I think the best way to do this will be to take them off one at a time and measure them off the Jeep. I'll start them at 23.5" and see how it is.

The rear camber was on the printout. Is there a reliable way for me to get a measurement? Maybe an angle finder on the axle flange? My angle finder isn't good for 0.5* measurements I don't think.

I'll let you guys know how it goes.
 
This weekend I lowered the pressure in my tires. That didn't make a huge difference (only went from 40 to 36 for the most extreme case).

I then removed the lower control arms, measured, lengthened, and re-installed. Turns out my measurements of the arm length while installed were very bad. I thought both sides were about 23 1/8", but they were closer to 22 3/4. This must've been my problem. I lengthened them to 23 3/8" (somewhere between what USMC Wrangler suggested and what Synergy recommends). The uppers are about 18 1/2".

After the control arm adjustment my caster angle is somewhere between 5-6 degrees. Pinion is something like 5 degrees. Handles much better now. Thanks for the help and advice!

It pretty much drives how it did before the axle swap. I suspect that the rest of my weirdness is from the worn out tires. Good thing I have new 37" BFG's waiting!

Based on how it drives, I'm guessing that 0.5 degrees of camber on the passenger rear isn't very significant. Does anyone have any thoughts on this final issue?
 

WJCO

Meme King
Based on how it drives, I'm guessing that 0.5 degrees of camber on the passenger rear isn't very significant. Does anyone have any thoughts on this final issue?

I would check it again, then spin the tire 180 degrees and check it again. Could just be a slight axle flange bend. That will tell you for sure.
 

OverlanderJK

Resident Smartass
This weekend I lowered the pressure in my tires. That didn't make a huge difference (only went from 40 to 36 for the most extreme case).

I then removed the lower control arms, measured, lengthened, and re-installed. Turns out my measurements of the arm length while installed were very bad. I thought both sides were about 23 1/8", but they were closer to 22 3/4. This must've been my problem. I lengthened them to 23 3/8" (somewhere between what USMC Wrangler suggested and what Synergy recommends). The uppers are about 18 1/2".

After the control arm adjustment my caster angle is somewhere between 5-6 degrees. Pinion is something like 5 degrees. Handles much better now. Thanks for the help and advice!

It pretty much drives how it did before the axle swap. I suspect that the rest of my weirdness is from the worn out tires. Good thing I have new 37" BFG's waiting!

Based on how it drives, I'm guessing that 0.5 degrees of camber on the passenger rear isn't very significant. Does anyone have any thoughts on this final issue?

You think going from 40 pounds to 36 actually did anything?


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You think going from 40 pounds to 36 actually did anything?


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Probably not perceptibly. I do know that the extra few psi is enough to cause a weird wear pattern. I tend to run my winter tires until May or June and as the weather warms the gauge pressure increases in the tires. The centers have worn down faster than the outside edges because I always forget to let some air out late winter. Basically, the tires are over-inflated from late March through early June and the wear pattern definitely tells that story.

I figure if it can cause a strange wear pattern, it might make a difference as far as steering feel. I couldn't really notice any difference, though ("not a huge difference" above roughly translates to "I didn't notice anything").
 
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