JunkHeap

I just installed a TeraFlex TF44 wide axle on my 2012 JK to replace a broken stock Dana30. I also installed TeraFlex track bar and drag link, their Falcon pass-through steering stabilizer, and Fox 2.0 adjustable shocks. The jeep drove perfectly straight while using the Dana30, but now the Jeep wanders (best word I can come up with) when I am on the freeway. I have to now drive with both hands and have to constantly correct my jeep back to the center of the lane. Wife refuses to ride in the Jeep because of the issue. The axle has some geometry changed to get the steering angles back to stock settings (so says TeraFlex) and the guys to do the alignment did get everything to match factory specs. After fighting the wandering for a while, I did have the guys increase the positive caster from roughly 4.5 to 6.2, and it did help somewhat, but it is still no where near how the Jeep drove on the Dana30. The wandering does seem to get worse with more weight in it, but that could be just my perception while driving it...

Any ideas on what could be causing the wandering and what I can do to fix it? As I already have more positive caster than I should need, so I don't think adding more caster is the right way to fix it, but I don't know what else to try. All the mechanics who have talked to me about it end up saying 'you have a lifted jeep, its gonna drive like shit', but they immediately go silent when I tell them that I didn't have this issue with my Dana30.

TheDirtman

Post up a photo of the alignment specs. I don't care for Teraflex so I don't follow all of their specs. Is the waste of money steering stabilizer gas charged? Are your tires over inflated? What rating on the tires? Did you wait to tighten all the control arm and steering link bushings at ride height and make sure everything is torqued. Were the ball joints properly torqued?

JunkHeap

I'll have to call the alignment shop to get another printout, can't seem to find the sheet any longer... Everything was within factory alignment spec with the exception of the caster. If I remember right, caster spec is 4.5 degrees +/- .5 but mine is sitting around 6.2 degrees. Tires are the awful BFG KM2 that I run around 31psi. I'm running them at the same spec as I did on the Dana30 when I didn't have this issue so I can't imagine it is tire related. Although I will say that the KM2s are a bit cupped so you do feel a bit of a shimmy at 50mph or so, but the KM2s were cupped while on the Dana30 so again, not really the culprit from what I can tell. And of course, I tightened and torqued everything when the Jeep was back on the ground under ride weight/height. While I haven't gone back and re torqued things since putting 1,100 miles on since the axle swap, MAYBE things are a bit lose, but I did have this wandering issue within about 250ish miles of the axle swap which was the first time going above 50mph due to running brand new gears.

What I can't think through is how I am thinking that ride weight plays into how bad it wanders. Cruising down the freeway with only myself, the Jeep rides pretty well and doesn't really wander and can control it with a loose one handed grip. But when I have my self, my wife and 450 pounds of dogs in the back, I have to use a tight two handed grip and constantly fight to keep the Jeep straight. However, when I have only myself and I'm towing a 1,200 or so pound loaded trailer, the jeep doesn't really wander. I could control the Jeep and trailer with a one handed grip if wanted, but I always use a two handed grip with trailers.

Overall, running the shocks at their firmest setting and having the steering stabilizer, regardless of personal feelings, on its firmest setting does minimize the wandering to a certain degree, but it doesn't completely eliminate the wandering.

JunkHeap

Here is the alignment report.

BoraBora

Your cupped tires could most certainly contribute to the wandering. 31 PSI is pretty high, and are likely why your tires cupping. Try going down to 25-28 PSI depending on how loaded up you are. I run my 37's at 21 PSI on my 2 door, and the wear is even and ride is nice.

You got a fresh axle, did it come with brand new ball joints? If so, this could be your issue; new balljoints can feel a bit flighty until they're broken in.

Torque everything and air down a bit. I would also reduce some of the toe-in. I actually like to toe my JK out a tad bit now, I find it drives perfectly straight and handles corners much better vs any of the toe in settings I've run over the years. I'd recommend trying different toe-in settings first before a toe-out. Test drive the same road after each adjustment.

JunkHeap

I do get the issue with the cupped tires, but again, the tires were cupped while on the Dana30 and my jeep didn't wander at all. Luckily these tires are just about done with life so I'll be replacing them in the next few months, hopefully it will help fix the issue.

Yes, the axle came with brand new ball joints. The only things I am running that are not new are the outer stub shafts and the outer knuckle. Both parts came off the Dana30 but are fine to be used on the Dana44 (so I was told prior to the swap). The ball joints are TeraFlex ball joints, which just so happen to be the same exact ball joints I put on my Dana30 about 3 months prior to breaking the axle. I truly do not remember having anything close to this wandering issue immediately after those I installed them.

I'm planning on torquing everything down again later this week so I'll play around with the toe a bit then and report back.

Thanks for the support!

BoraBora

I don't know how your suspension or steering was setup before, or what your alignment specs were, and this is pure speculation...but it could be that your JK had a slight pull before, and the tires kind of evened it out. Or maybe one of your tires has a more substantial pull. Were your tires rotated when the new axle went in?

Before I redid my entire front end, my Jeep drove perfectly straight with my Fox SS. Now it pulls left due to the same SS I had before. So the gas charged SS was a bandaid for a right pull I hadn't even come to notice before. Now with my SS pulled off and same tires, it drives perfectly straight.

So if you check all your torque, and reducing some toe-in doesn't alleviate your issues, I'd try rotating the tires to make sure it isn't a radial pull. If that still doesn't do it, then I'd double check to make sure the TF ball joints (lowers) have proper preload.

Good luck, and report back!

JunkHeap

When we bought the Jeep, we understood that the previous owner just wanted a Jeep that 'looked cool' because she built it with garbage parts and used an installer that didn't know what they were doing. Missing bolts on the track bar mounts, factory pitman on a 8" lift, two 2" wheel spacers on each wheel, 37" tires on stock gears, and the list goes on and on. Hence why we named the Jeep 'JunkHeap' and are proceeding on building it the right way. But when you find a non-wrecked 2012 JK with 13,000 miles for sale for $11,000, I could overlook some things!

I will admit that the shop that helped install the rear locker the week before I did the axle swap did a 'nice' thing and rotated my tires. Immediately had death wobble so I took it back and had them rotate tires back to how I had them. I kinda doubt that things are back to pre-rotation location as I feel I have a little more shimmy at 50mph than I did before. Pure speculation on my end as well, but it does lend credibility to your line of thinking. Are you running your JK without a SS, or did you change from a Fox to another brand?

From what I understand about toe, toe out causes the jeep to handle better in corners but can make the vehicle 'wander' in straights. Toe in makes the vehicle more stable/straight on straights while sacrificing control in corners. If that is correct, shouldn't I increase toe in, not reduce toe in?

road1will

Try toeing the front in a hair more and drop your air pressure down to 27psi.

TheDirtman

Your rear axle is not in line with the front.

I would start by removing the new steering stabilizer and see if it still wanders. Drop the tire pressure too. 24-28 psi.