crossover steering and wandering at high speed

[blistovmhz]

98 XJ, WJ kuckles, 1 tonne crossover, 35x12.5, etc.
I've definitely got some rear steer going on due to bad leaf angle, but I'll be addressing that next week (was going to throw some 63" chevy leafs in today, but everything's closed for the long weekend ).

The rear steer however, is NOT the cause of my wandering steering and wondering if anyone's got any suggestions.
Toe is correct at 1/8" in (and I've tried toeing further in as well as out), camber is good, and caster is about 6 degrees. Self centres nicely every time. No bump steer.
The only thing I can come up with is either I need more caster, or a steering stabilizer.
My pinion has lots of room to go up or down a few degrees, so adding more caster isn't an issue, but I figure 6 degrees should be sufficient. I've tried from 3 all the way to 6, and 6 is where it self centres well.
I didn't bother with a steering stabilizer, as my thoughts are that they're really only there to mask a problem. Perhaps I'm wrong? In a perfectly setup cross over, is a stabilizer necessary to keep the Jeep tracking straight?

By wander, I mean the steering feels a tad sloshy at high speed (but everything is perfectly tight) and I find it a bit of a chore to just drive down the road straight. Constant need for small corrections all the time, and it always wants to pull down the road crown, regardless if the crown is on the left or right. It all points to insufficient caster, but due to the excellent self centering, I keep looking for something else.

Idea's?

 

[yossarian19]

Let's say they cost Chryco just $10 apiece to put them on a Jeep.
They went on each and every WJ that went down the line, as well as ZJ, TJ, XJ and MJ models.
Well, the WJ, they made 1.5 million of them.

If the smart guys over at Chrysler thought they didn't really need to be there would they have spent $15 million bucks or so putting them on WJs? How much did they spend putting them on their other models?

I can't think of a solid front axle vehicle that *didn't* have them after 1970 or so.

I put one on my old truck that has a knuckle to knuckle tie rod (different orientation draglink though) and it made a world of difference at highway speed. Less wander, bump steer is less pronounced, steering feel improved.

 

[blistovmhz]

Let's say they cost Chryco just $10 apiece to put them on a Jeep.
They went on each and every WJ that went down the line, as well as ZJ, TJ, XJ and MJ models.
Well, the WJ, the made 1.5 million of them.

If the smart guys over at Chrysler thought they didn't really need to be there would they have spent $15 million bucks or so putting them on?

I put one on my old truck that has a knuckle to knuckle tie rod (different orientation draglink though) and it made a world of difference at highway speed.

That line of thought is PRECISELY why I asked. I can see Chrysler ****ing up a lot of things, but I can't see them spending money on parts that didn't add performance value.
That said, I don't see why a stablizer would solve the problem. I can imagine that without the stabilizer, my wheels want to follow the path of least resistance and a stabilizer will certainly slow the tie rod from following that path, but ultimately isn't the stablizer just slowing down the train wreck? They don't add any self centering to the system, so I just can't see how they help the vehicle track straight.
I always thought their primary function in a stock vehicle was to absorb small quick transitions.

I've got a few spares lying around and I could fab up some mounts today. Ya know... Just wanting to make sure I've solved all the problems that can be solved, before applying bandaids. If a stabilizer really is the RIGHT answer, I'll go stick one on and see what it does.

 

[desertmike345]

Had the same wandering problem on the MJ. Everything looked good. I finally changed the upper control arm bushings on the axle. They didnt look that bad but solved the problem.

 

[Jeepedo129]

I'm literally at the exact same position as you. On the freeway, I find myself constantly moving the steering wheel. Ive checked everything for play, and everything seems solid. Only thing I haven't tried is a stabilizer. But as you said, I feel like it's more of a bandaid. I'll be interested if it fixes your issues.

 

[Demonoid369]

The stabilizer wasn't used as a band aid but over time it got branded as a band aid. Think about how the road is, tracks are worn into the road as thousand a and thousands of cars pass over, creates ruts. Your tires are trying to fight back and forth those valley and mountains, especially if you have wide tires. They're meant to lessen the harsh abrupt bumps and steering changes but also to help lessen the wandering

 

[blistovmhz]

Nope. Stabilizer didn't change anything other than making my lock to lock slightly slower. No change on highway, still wandering.
I'm goona get the rear suspension sorted (this week I should have the 63" chevy leafs installed) and see if that changes anything.
I've never had any issue getting my Jeep to track nicely, regardless of lift. Dunno wtf this time. I guess we'll see how the rear suspension does.

 

[zachandandy]

1 word on why the oems started putting stabilizers on WARRANTY. There are thousands of solid axle vehicles without them that drive down the freeway beautifully. If everything is set up properly AND everything is tight they are unnecessary. How many millions do you think oems saved by the stabilizer masking potential warranty claims? Check all bushings and bolts as it sounds like something is loose or worn to me. Rear steer could easily be the cause of the wandering as well.

 

[RNMedic]

where did you measure the toe in? I had a 1/8 on 33's at front of tire, which translates to about 1/4 on stock tires, took it back out to 1/16 and helped a bunch.

 

[lazyxj]

98 XJ, WJ kuckles, 1 tonne crossover, 35x12.5, etc.

Is the wandering a new problem, with an old setup, or is this an updated suspension/tire system that is having a problem?

35" tires have a very tall sidewall and will never track as straight as a smaller diameter tire due to the sidewall flexing.
Many newer trucks have tall tires and run 17 and 18" diameter wheels to shorten the sidewalls, for better handling and tracking.
Cal pointed out in a earlier post that 15" and 16" tires are slowly being obsoleted because of the trend toward larger diameter tires.
What you are experiencing may be normal for your setup.

My XJ's steering and suspension is tight, but on 33"s, it still wanders a little bit at speed, not dangerous but you do need to pay attention.
Switching back to the 31"s, the Jeep is more stable and responsive to steering input.
Try adding a little more caster and see what happens.

 

[ocean_jet]

I had the same issue. I adjusted the LCAs out as far as possible. That fixed it.

 

[lazyxj]

I had the same issue. I adjusted the LCAs out as far as possible. That fixed it.

As long as the front axle's pinion angle remains between 1/2-1 degree (from FSM), this is a good fix.
More pinion angle will lead to a front driveshaft vibration, especially with tall lifts and axles that have been regeared.

 

[blondejoncherokee]

look for bad leaf bushings, and long shackles .

Look for bad control arm heims/bushings

Are your steering box bolts tight?

Are your ball joints brand new?

what is your caster?

a combo of too little positive caster, bad bushings, and bad trackbar heims or bushings will do it.

 

[ocean_jet]

As long as the front axle's pinion angle remains between 1/2-1 degree (from FSM), this is a good fix.
More pinion angle will lead to a front driveshaft vibration, especially with tall lifts and axles that have been regeared.

I was worried about drive shaft vibes, but luckily didn't get any. Not sure what my pinion angle is.

 

[Mach2nh]

Locker in the rear?

 

[blistovmhz]

Locker in the rear?

Yup. Front and rear.

 

[rockclimber]

pulling down the road crown is indicative of bad caster.

a steering stabilizer will help with things like potholes from jarring your wheel and it will also protect the box from road vibration, which will kill the bearings.

 

[blistovmhz]

Pulls down the crown, wanders, and goes left when I give it some throttle and right when I let off.
I thought the pull during throttle was due to leaf angles, but I got that sorted today and it's still doing it. Leafs are at the correct angle, and much stiffer than before. Axle isn't wrapping, just wants to go left with gas and right when I let off.
Tires are all even, and I've rotated a few times.
I really think all three issues are being caused by the same problem.
As I mentioned, I've pulled the caster way positive and doesn't help. Steering self centres aggressively when I set it too positive, but still wanders.

 

[XJLI]

goes left when I give it some throttle and right when I let off.

This is your rear locker. I'm sure something else could be exaggerating it, but letting off/on the gas will make the truck try to change direction.

 

[blistovmhz]

But why? The other truck (k1500) has lockers and doesn't do this.