PT20J

During annual inspection, I noticed a rubbing noise emanating from within the left wing during the last inch or so of the left aileron travel in the up direction. Some investigation revealed that the sound comes from the aileron control link rubbing on the aft side of the phenolic guide block at wing station 133.0. The paint on the tube is rubbed off, but the tube appears undamaged and there is no metal-to-metal contact. I cleaned all the wing guide blocks and regreased with Aeroshell 7 to no effect. The right aileron does the same thing to a lesser extend, but I haven't opened up the right wing yet to verify that it's the same guide block. I'm wondering if anyone else has experienced this and found a way to correct it.

I removed the trim wheel and gearbox assembly from the airplane to examine it. The steel trim wheel shaft runs through a hardened brass bushing. In my case, both parts were worn causing the wobble. The service manual doesn't mention lubricating this part -- probably because there really isn't a good way to lubricate the bushing without removing the chain, driving the roll pin out of the sprocket and removing the trim wheel/shaft and applying grease. A better design would have been to use a standard size oilite (oil impregnated sintered bronze) bushing. I ordered a new shaft and bushing and plan to drill a small hole in the top of the bushing. That way, at annual I can remove the plastic chain cover and pump some grease in with a grease needle. Skip

I've noticed a bit of wobble in the trim wheel on my M20J. It wobbles maybe a quarter inch left to right when the wheel is grasped at the top or front. Anyone know how much wobble in the bushing is normal?