The Cessna 120-140 Association Forum

Hi we have a C120 ,1946, and wanted to get some ideas on the correct alignment methods we are going to put solid axles on soon and our tires are wearing on the outside edges badly
Your advice is much appreciated

If you can get your hands on a copy of the Cessna 100 series maintenance manual it's covered there.

My initial check is to hold a string on the outside edge of the tires and see where it locates on the horizontal stabilizer. If I remember correctly it should be 8-11 inches from the tips. If one is a lot different than the other, that is an issue.The outside wear is pretty typical as the gear is hanging down and narrower, which makes the touchdown on the outer edges of the tires.

Wear on the outside is typical. You can reverse the tires on the rims to get more mileage. The left side on mine wears more than the right most likely because because I fly solo a lot. I then swap the wheels to get a bit more out of the tires.

The outside wear can be from too much toe in also! Make sure you use "grease plates or wheel alignment plates to relive the tension on the wheels to get correct reading.

When I first got my plane the tires were badly worn on the outside. I finally figured out someone had installed the shims backwards. Once I fixed that and reversed the tires they wore evenly.

Thanks for all the help

Literally just finished doing this today. The Cessna Service Letter SLN 56 is a great description but I also found this attached figure from the 100 Series workshop manual useful so I added the other necessary data to the original to make a one-stop diagram for sticking to the aircraft whilst doing the job...
The thing I found was that you need to measure from your set square to both the front and rear edge of the wheel centre flange as the bulge in the tire will mean that you can't place the set square onto the centre hub directly. I found that using a set square and then spike end of a micrometer to read the distance to the front flange and rear flange worked well. Easier to do than to describe. Don't forget to halve the difference between the two readings as toe in/out is from the centre of the wheel to the flange as described in SLN56.

Mine were 1/64th" out. In tolerance basically. I also checked the camber using the method on the attached. Less than 1 degree. But I too have scrubbing on the outer edge of the pilot side tyre. Conclusion ( supported by the service letter ) is that this is due to improper over inflation by yours truly when I was new to the aeroplane. Others at my flying club reminded me that Spitfires routinely scrub the outer edge of the LHS tyre so that makes me feel better !