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Dear Jim,

I drive a 1995 Ford F-150 (4.9 L, L6) equipped with a six-inch SuperLift suspension and 33-inch mud tires. If I turn left and there's a little bump in the road, the wheel on the front passenger side starts to hop and the truck shakes violently until I straighten out.

I've already balanced and aligned the tires and had the suspension system checked twice, but none of these shops can find anything wrong, maybe because the shaking only happens at about 35 mph or faster.

One guy did tell me I was experiencing "bump steer" -- what is that?

-- Mike Jimenez

Well, bro, I don't do a lot of work on lift kits, but my experience is that when any automotive system suddenly stops working right, something's either loose or broken. In your case, I'll bet it's a worn stabilizer shock on the right side.

Without getting too technical, you should have a horizontal stabilizer shock on each wheel to control vibrations in the steering system. If you had, say, a 2000 Ford Contour, it wouldn't need these. A lifted F-150, on the other hand, needs some extra stability in a big way, and if the right-side shock goes bad, it easily could create the symptoms you're describing.

Get both of these shocks changed. They're cheap and easy to acquire, so parts and labor shouldn't cost more than $100 or so.

As for "bump steer," that's just a silly term some mechanics use to describe what happens when you hit a bump and your steering gets wobbly. If that's what's happening, obviously there's something loose in the steering assembly.

The real question is, what's loose? I'm sticking with the stabilizer shocks, but it's also possible that something's wrong in the steering linkage. If so, you'll need to take your truck to a qualified suspension expert who can test it at the right speed.

This will cost you some money, brother, but that lift kit you've got is a special component, and sometimes that means seeing a specialist.

Tip of the Week:

Feeling a little change in the weather? The real chill is still some weeks off, but it's not too early to think about winterizing your vehicle: flush the cooling system; replace wiper blades; keep the tire pressure up; test the heater and defroster; get a brake check. Also, keep that gas tank at least half-full -- it'll help keep moisture out of the fuel line.

Buffalo Jim, owner of Allstate Auto & Marine Repair in Las Vegas, writes a weekly column. Send your automotive questions to him at buffalojim@lasvegasniftynickel.com. If Jim picks your question to answer in Nuts & Bolts, you'll also be the proud recipient of a deck of official Buffalo Jim playing cards, presented in a classy, tin box bearing his hairy image.