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Knucklehead97

Brothers Dw Is Back

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After we thought it was finally gone, he hit a bump and his XJ went crazy. We've had DW problems with his Jeep XJ since the week we bought it in 2011. We started by paying a shop (bad idea. Was way overcharged) to change the tie rod ends, track bar ends, lower control arm bushings, and the upper control arms bushing (at frame. We changed the axle bushings ourselves). After that didn't fix it, we adjusted caster and got an alignment, still didn't work. So we did the infamous ball joint change and hey! That worked! Until now... the ball joint change was this time last year. He got a set of used tires a couple months ago and it didn't wobble until today. The tire balancers seem a little off and he only has 4 lug nuts per tire, so I think that might be a problem. Otherwise during the ball joint change we lost one of the lower joints nuts (the passenger side) so we put the old on but we couldn't get the cotter pin in because the nut was weird with the new joint. And now that I looked underneath, the nut has backed off and seems to be about 1/8" off of the steering knuckle. His steering stabilizer is also shot I think. I was going to tighten down every bolt to spec, add a 5th lug nut to all rims, and maybe let him borrow my steering stabilizer. His truck is lifted about 4-5" with about 32" tires, if that helps.

 

Thanks

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Tire balance is probably the number one cause of your wobble. Also check to see if maybe you bent a rim.

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We had the tires balanced by the shop when he bought them. Could they have done it wrong?

 

Absolutely.

 

To reiterate what Biotex wrote in post #2:

 

Tire balance is probably the number one cause of your wobble. Also check to see if maybe you bent a rim.

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Definitely will have it checked when we can. Is there anything I can do from my own yard to check it or fix it? And could that ome missing lug nut have any effect on balance?

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We had the tires balanced by the shop when he bought them. Could they have done it wrong?

.

Could be they didn't do a dynamic balance, or that they screwed up a static balance. Easiest way to tell if they did a static balance is if there are only  wheel weights on one side (usually inner side of the wheel, because some customers complain about visible weights on the outer side detracting from the beauty of fancy alloy wheels). Though static balance is fine in the vertical plane, tires are  also out of balance in the lateral plane to some (greater or lesser) degree. This typically shows up at 50-55 mph, and can become quite violent when in combination with other factors such as big tires, lifts, and any front end problems otherwise so marginal as to go otherwise unnoticed until triggered and amplified by harmonic oscillation.

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I checked and they put weights on the inside and out. One tire have equally sized weights but one was a tiny bit bent. And the other side had a much smaller weight on the inside than it did on the outside.

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We had the tires balanced by the shop when he bought them. Could they have done it wrong?

 

Did they balance the the tires using a Hunter Road Force balancer? For stock size tires it probably not necessary, but for 31" on up, I've found out that these machines do the best job by far. The local Chevy dealer in town has one and I always go there for tire install and balancing after learning the hard way. Of course the balancer is only as good as the operator.

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Hornbrod; I have no idea. I didn't know there was a difference in balancers and all that which work better with bigger tires.

 

Carnuck; how does that help? I've never heard of someone doing that.

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I've had tires that couldn't be balanced by conventional spin balancers, and came out smooth using the Hunter road force machine. The Hunter balancers are expensive, so your local Mom and Pop shops probably still use spin balancers because of the cost. Try to balance your bro's tires at a place that has this balancer before resorting to other means. Call around. Usually the balancing cost is the same.

 

http://www.hunter.com/balancer/roadforce/

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His tires are 265/70r17 which comes out to around 32/11/17 in standard terms. I don't think the airsoft pellet balancing would be as effectice as the Hunter balancer. On other terms, could someone tell me why after my balljoint change (did them last weekend) my trucks steering feels tight and when I hit a bump it shakes some and makes the truck veer some to the side? The wobble I had before, destroyed my new front tires, so I'm moving them to the back amd the backs to the front tomorrow after I change the shocks (front drivers side is a b**** to get to under that brake booster!) I haven't had it aligned at all even though I changed the tie rod ends, track-bar, and steering stabilizer in March. Thanks guys

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I agree on the balancer. When I did my homemade front shock extenders on my Comanche (shocks were brand new so I threaded 2 pieces of pipe to screw on and an exhaust stud for the bushings on top), I undid the 2 bolts holding the master to the booster and lifted it slightly (gently bending the brakelines)

   The pull and wobble means it's time for a wheel alignment. I wonder if the original balljoint was bent or possibly a camber adjusting version?

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I'm doing my own alignment tomorrow (gotta love being able to do things decently yourself!) And I talked to the shop that balanced my brothers tires before it started wobbling again, they said they had a Coax balancer. And also said that since its lifted that its probably alignment of the camber? I'm going to check his actual tie rod alignment tomorrow and may research the correct camber degree for the lift (even though I don't know the maker of the lift or how high, havent been able to measure) my dad adjusted his camber a long time ago, and he didn't know much about Jeeps. So that may be it. What you guys think? (Hunter balancer idea is still being worked out )

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Never heard of Coax. Maybe Coates?

Could definitely be that. Was talking to them in the shop so it was loud. The guy even told me that tire balance has no chance of causing wobble in the front end, but I know that it does because new tires fixed my wobble for a little bit until they got wore in.

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Knucklehead97, on 21 Nov 2013 - 08:41, said:

 

carnuck, on 20 Nov 2013 - 02:11, said:

Never heard of Coax. Maybe Coates?

Could definitely be that. Was talking to them in the shop so it was loud. The guy even told me that tire balance has no chance of causing wobble in the front end, but I know that it does because new tires fixed my wobble for a little bit until they got wore in.

 

Sure it does - tires out of balance can provide the initial wobble input that gets amplified by other front end faults. There is often a trigger event though, like hitting a bump, that sets the stage by cocking all the slack in the front end to one side, then the tire imbalance wobble starts oscillating harmonically to the limit of travel allowed by all worn suspension components. (There are other harmonics in the front suspension that can oscillate independently of tires, though, but tires are the initial big offender here.)

 

Balancing your tires of course will not repair the faults in your front end, but it will reduce or eliminate "death wobble" for some amount of time.

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The guy in the shop clearly does not know what he is talking about. Tire balance is the primary cause of death wobble. Other factors just combine to dampen and hide the symptoms to a greater or lesser degree. In theory, an automotive tire is a gyroscope, which is inherently resistant to wobble -- IF it's perfectly balanced. If it isn't perfectly balanced, it will wobble.

 

Secondly, camber in a solid front axle setup like the XJs and MJs is not adjustable, except by installing special offset ball joints. That's not so much an "adjustment" as it is a one-time fix for an out-of-spec axle assembly. Lifting the vehicle will affect caster, but will not affect camber. Lift also affects toe-in.

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I figured he didn't know what he was talking about. He got very defensive when I asked if he knew anyone with a Hunter Balancer, wouldn't even tell me if he knew a shop that would have one.

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Lift reduces caster angle, and keeping caster angle around 7 degrees is important for resisting death wobble. The problem is, with a large lift if you dial in 7 degrees of caster you may increase the operating angle of the front axle u-joint beyond where it's happy (since there's a double cardan joint at the transfer case end, the operating angle at the differential yoke wants to be approximately zero). So generally setting caster on a lifted truck becomes a balancing act between getting enough caster without eating u-joints.

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Well I'm back. Wanted to see how it drove myself so I greased up his tie rod ends, track bar, and drag link. Took the truck going about 60 down a road with a few nice bumps, trying to get it to wobble and it wouldnt. So I sent him off feeling good about it and he drove it for 2 weeks. Then yesterday I had a church play and he came to it after work, and let me drive home cause he was tired from work. I come down a mountain going 30-40 and hit a bridge, then coming off the bridge I hit a bump and wham! dw is back! And no, we never had the tires rebalanced with a hunter balancer (we've been busy so neither of us have gotten the chance to ask around. Gonna check at the local jeep dealer while we're in town tomorrow.) Should he also get a steering stabilizer? I do believe his is almost shot.

 

Thanks

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