Questions and Answers – Wobbly Steering, Taxi and Landing Light ReplacementWritten by Steve Ells
Q: Dear Steve,
The steering on my Piper Arrow III (PA-28R-201) seems loose. I have had this particular Piper for seven years and it seems like it’s getting more difficult to keep it tracking on the centerline—especially on paved runways right after I apply power for takeoff. As soon as I get going, it seems like the problem goes away.
I don’t think it’s a big deal but I don’t really know for sure. Can you shine a light on this? Is there a solution that doesn’t cost an arm and a leg?
A: Dear Wobbly,
As you can see from the parts drawing that accompanies this, Piper nosewheel steering systems consist of a pivoting beam that’s connected to the rudder pedals through one or two (depending on the airplane model) steering rods. There are two lobes on the forward face of the beam (part number 76409-00 and called a “Cam Assembly, Steering” in the Arrow III parts book) that are situated in close proximity to two round rollers—one on each end of a bell crank that is connected to the nose landing gear.
Any movement of the rudder pedals causes one of the lobes of the pivoting beam to contact one of the rollers, transmitting motion to the steering bell crank at the top of the nosegear.
In the beginning, there was very little clearance between the two rollers and the two lobes—they couldn’t touch because that would put a load on the pivoting beam center bushing when the nosegear moved into the down position. In time, due to wear on the lobes because of the effects of dirt and grit or a seized bearing in one or both of the rollers, the gap between the lobes and the rollers widens, allowing the nosegear (and tire) to wander back and forth in the spaces between contact.
Normal maintenance requires that the two rollers be checked to make sure they are both free to rotate and that they are not worn unevenly. If the lobes that are part of the pivoting beam (cam assembly) are worn, they can be repaired by Bruce and Shirley Toftt at S&B Industries in Murray, Utah. Bruce Toftt quoted a price of $100 to $150, depending on the model of the cam assembly.
Once the cam assembly is repaired, your wandering days will be over.