I was wondering about camber on Cessna taildraggers. I've owned three of them now, the first two (esp my 170) had very obvious positive camber (top of wheel out). My 180 is set up with pretty close to zero or neutral camber, at least to the naked eye. My series 100 service manual says that (on the old greased plates, of course) with tanks & cabin empty, there should be approx. 4 to 6 degrees of positive camber. This will give approx. neutral camber at gross weight.

I see each side has a extremely tapered axle shim that if removed should give me a nice positive camber.I'm getting ready to pull off the wheels & repack the bearings as part of the annual, so this would be the ideal time to address this. I do plan on carefully measuring the shims, hopefully they're just tapered in the one direction so that by removing them I won't be screwing up the toe-in. I don't wanna do that because the airplane handles really well as it is.

Besides doing it just cuz the book says so, it seems like you want more rubber on the road as you approach gross weight. Plus, if you're lightly loaded much of the time, positive camber tends to concentrate tire wear on the outside half. You can flip the tire on the wheel every year or two and get twice as much mileage out of them.

Thoughts?

If it tracks nice on pavement especially with the tail up don't mess with it.

I'm thinking you won't get twice as much mileage out of them. Think, half the tire=twice the weigh=faster wear. If anything, I think it would wear out faster due to higher usage on the outside edges then the center, causing it to wear through there before the center is worn much at all. Even wear will get the most wear in my limited learning.

Nuther test I learned about is to get the plane on a "flat" concrete hangar floor, be sure both tires have same pressure.
Roll it back an forth a few times - or greased plates - measure wing tip distance to the floor. Was told there is a 2" Max. <total> difference allowed.

If out of specs. could be a bent gear leg. If gear legs both look the same (?) there is some shimming that can be done somewhere in the gear box. Outer portion as I remember.

Been a loong time since I read the 100 series manual.

Now I could have been told a rashin of @#$- BUT mine measured as 2-1/8. Decided on new legs.

Hope it helps

Trim

Aligning Cessna gear is not rocket science, but it can take a lot of time and fiddling, which is why most mechanics hate doing it.

Doing this without a mechanic signoff is probably not "preventive maintenance" but in any case, I'd get with someone who's done it several times before to look over your shoulder.

Messing this up can result in a very ugly ground handling plane, and possibly an accident.

Finally, if the plane seems to handle well on the ground, as in doesn't pull either way, tracks well, etc, I'd leave well enough alone.

MTV

mtv wrote:Finally, if the plane seems to handle well on the ground, as in doesn't pull either way, tracks well, etc, I'd leave well enough alone.

MTV

Amen. The C172 TD I have now had a cracked gear box on the left side which let the gear leg move aft and made for some nasty ground handling with cross-wind landings on pavement. Once fixed and properly aligned, it's a docile as a lamb. Absolute pain in the ass to fix it, but worth it.

Gump

It is a pita to do.

I took a gander at the vertically-tapered shim at the LH axle today, looks like it's tapered fore-and-aft as well. So removing it would get me the positive camber I want, but at the cost of screwing up the good toe-in it seems to have now. I'll take a closer look when I take the wheels off to do the bearings, but right now it looks like I'll be leaving the shims alone. FWIW I measured the tread depth on the tires, looks like the tire is wearing quite evenly as it is now.

Actually, I believe there should be at least two shims on each axle. That's where it gets complicated, as you note. And, as Tom and both mp lied, it can be a PITA.

I've seen some Cessnas with terrible gear alignment......a friend called one evening, asking if I'd go fly with him in his 170. He'd had it for a year, and it was to the point that he wouldn't take his family flying with him, because the ground handling was so ugly.

We went out the next day, and I was impressed on his first landing at how hard he was working at it. So, next one was mine. After that, I was even more impressed at how well he'd handled that first landing, and it was quite clear why he was considering selling the plane.

We taxiied over to his maint. shop, and had a chat with the owner, who wanted no part of gear alignment......but, with a little assertiveness, he caved in.

Made all the difference in the world.

When I moved to MN with my 170, a local sprayer with tons of experience in t/w planes commented one day that I must be a hell of a pilot, flying that 170. I thought he was being a smart Alec, but turned out he was serious. I asked how many 170s hed flown....."Just one". Mystery solved. Later, he flew as instructor in my 170 for the gent who bought it from me.....he called and told me that was a really nice handling plane.....high praise from him.

I've flown Cessnas that ranged from just flat ugly to ones that kind of seemed to have a bit of a mind of their own at times. My 170 was one of the latter, till I had some great mechanics align the gear.....reluctantly. It made a difference, not a huge difference, but I'll take all the help I can get.......

So, if your plane sometimes seems to do things on the ground that you can't take credit for..... ..... Find a good Cessna mechanic and prevail upon them (or bully them) to check gear alignment.

But, if it doesn't do anything strange, leave well enough alone.

MTV

mtv wrote:.... if it doesn't do anything strange, leave well enough alone.

Yup, good advice-- if it aint broke, don't fix it.
But who amongst us hasn't ignored it?
After all, that's where longer props, bigger tires, and more powerful engines all came from.