First of all, check the steering damper. It looks like a shock absorber, but moves equally hard in both directions while shock absorbers pull apart hard and push together easily. The damper is in front of the front axle, attached to the steering linkage and the axle housing. One end of it is almost exactly in the center of the truck. This is the end where you will see oil leaking from.
After a front end alignment, it is possible to tighten one of the tie rod adjuster clamps in such a position that the bolt rubs against the damper and chews a hole in it.
A related, very common problem is a worn track bar. This bar is about 1 3/8" in diameter, attaches to the passenger side of the axle with a rubber bushing, and has a ball and socket that attaches to the frame just under the power steering pump. It has a big curve in it to go over the differential too. The ball and socket is what wears out at very low mileage, and causes steering wander. Chrysler allows.080" of vertical movement before it must be replaced, but that much movement would render it almost uncontrollable. At.020" play, driving the truck will be irritating.
The procedure for checking the track bar involves attaching a dial indicator, but experience has shown that isn't necessary. Start the engine and have someone move the steering wheel back and forth about 1/8 turn once per second while you watch the ball and socket. If you see any movement up and down, the bar must be replaced. The weight of the truck must on the tires for this to work. Keep in mind the track bar won't cause the shaking, but it will definitely aggravate it.
Caster is one of the three primary alignment angles. It has very little effect on tire wear, but a big effect on pulling to one side, easy vs. Hard steering effort, and steering wheel returnability. If it is too high, it increases road shock over bumps and can aggravate the shaking sensation from the steering wheel returning to center so fast that it overshoots and goes the other way. On Dodge trucks, caster can not be adjusted on only one wheel; the entire axle can be easily shifted during an alignment but both wheels will change equally. That means caster can't be used to fix a pull, but it can adjust road feel and steering effort.
The first thing to do is have a professional inspect the entire steering and suspension system. Some shops, such as Sears Auto Centers do this for free as a way to get you to come in. They get paid when they sell you something. Dealerships charge for this service because no one wants to work all day for free. They are often so busy, they aren't interested in selling unneeded repairs. They also have a vested interest in making their product perform like new.
It should also be understood that my caster, track bar, and damper stories only apply to four-wheel-drive Dodge trucks. Two-wheel drive trucks do have separate caster adjustments for each front wheel, and don't need a track bar.
Friday, March 20th, 2009 AT 10:02 PM