Shimmy in front end at 50 - 57MPH

zipXJ · 10-20-2008, 10:16 PM

All 3 Jeeps I've owned eventually develop this same problem....an annoying shimmy in the front end that always seems to occur at this same speed. 50 - 57MPH. The first 2 I just dealt with because it wasn't that bad. This one I'm going to have to fix. It's not un-drivable but clearly getting worse. I will be getting the wheel balances done again very shortly to eliminate that variable.

I've recently heard it could be due to the Pitman type steering (can you tell I'm not an expert wrench??). I've also heard a good fix is to go with something like an ORO replacement which runs about $700.

I don't off road with her so I'm wondering if I shouldn't just fix the stock system??? Here's my question...

Is there a part of the steering assembly typically more prone to wear? Some way of identifying which part needs replacement??

Like most of us my cash is tight right now so any help would be GREATLY appreciated! Thanks!!

Southerntracker · 10-20-2008, 10:49 PM

If re-balancing doesn't solve the problem, check to see if the lug nuts are torqued properly. They should be at 75ft lbs. I've learned that if a shop over-tightens the lug nuts I get a bad vibration around those speeds as it warps the rims and rotors. I now make them manually hand-tighten them with a torque wrench.

zipXJ · 10-20-2008, 10:56 PM

Thanks! I didn't think about torque. If the rotors are warped wouldn't I also have some braking related issues?? Good info however. When I have them balanced I'll have them tighten to 75ft/lbs.

NHCOP · 10-21-2008, 08:17 AM

When I first got my XJ and when it was stock, it had the 50-60mph vibes. My tires were out of balance and worn unevenly. Got a new set of tires and balancing and it rode like new.

surviorcamaro · 10-21-2008, 08:53 AM

my xj had the same problem and it turned out to be bad upper ball joints and track bar. got new ones in and problem fixed.

rust64 · 10-21-2008, 08:56 AM

I agree with NHCOP. If the shocks are worn, and the tires are out of balance, it's a situation where one feeds off the other and the condition worsens. The tires start wearing "square". When you have the tires rebalanced, watch the tires spin on the machine, looking for both longitudinal and lateral runout. If the tires are messed up permanently, you'll be able to see it. If they are too badly worn, I think the only thing to do is get new, "quality" tires. My shocks were so bad, my back started to bother me. I replaced the rear shocks and it rode way better, and my backache went away. So, I replaced the front shocks and the ride and handling improved some more. But occasionally I could feel this shaking. It would come and go, because I think the lumps on the tires would "line-up" and add up to this shaking. So, I bought some new Michelins, and, voila' it rides awesome, now.

CharlieMopps · 10-21-2008, 09:05 AM

Check your balljoints. If its them, your tire could literally fall off. I just went to replace mine, and the lower was so bad I think it was actually on the verge of shearing off.

Belizeman · 10-21-2008, 09:09 AM

1997 Wrangler had similar problem.
New $30 steering arm shock absorber cured this condition.

Rollin · 10-21-2008, 09:12 AM

In addition to all of these, worn out unit bearings can also cause a shaking that feels like a balance problem.

Rtbeebe · 10-21-2008, 10:18 AM

This was my problem as well. I went to a Big O for new tires and the tech pointed out that three of my wheels were out of round side to side. Watching them on the balancing machine it is very clear they were shot. I bought three new-used wheels from a yard and had them checked. Got an alignment by a mechanic who was in no hurry to get me out the door and got all numbers to zero. Jeep rides like new. It may take some time but check all these little things. The suspension and steering are so stiff that anything feels like things are coming apart.

JGriff99xj · 10-21-2008, 10:30 AM

zipXJ. I just resolved this problem with my 99. I run 33 inch tires on 10 inch wide wheels. My jeep has 149,000 on the odometer with the front ball joints and wheel bearings still all original. I thought it was the ball joints or the wheel bearings, but it wasn't. I wanted to start with the cheapest things first. I went to the shop that i trust and they computer spin balanced my wheels. The thing was is that when i got my tire and wheel package, the shop only put weights on the inside lip of the wheels so it would look good. Well with 10 inch wide wheels with 3.75 inches of backspace, there is 6.25 inches of wheel and tire sticking out to past the hubs. My wheels were really bad out of balance. So the shop put weights on the inside and the outside of the wheels and my jeep rides better than it ever did. So just get your wheels and tires balanced first. It cost me something like $48.75 and thats probably the best money ive ever spent on my jeep.

zipXJ · 10-21-2008, 10:48 AM

This is great info guys...thanks a ton!

The tires are fairly new and are wearing very evenly. I replaced the steering arm shock on my last XJ but not this one...so that is a possibility. Ball joints are also original (God I hope that's not it!). I replaced front and rear shocks at 59k miles so they should be fine.

That leaves a balancing issue (I drive very few miles so it is possible they are out of balance and showing no abnormal wear)....steering arm shock and ball joints. ....and rotors....gulp! Original equip rotors are VERY expensive and honestly I've never had good luck with aftermarket rotors. Anyone know of a good brand??

I'll start with the balancing - replace the shock - then look at ball joints / rotors in that order.

Thanks everyone for all your input!!