The International Cessna 170 Association

Well, replaced the main tailwheel leafspring last week......only to find that the there is a crack in the bracket! Probably the result fo the leaf spring being overextended/stressed for so long.

I have the later model alligator bracket or one with fingers. The part that is cracked is what is described in the IPC as P/N 510000-31 "Channel - Tailwheel Spring Retainer"

The shop thought that it could be weld repaired.....is that legit, or is it opening up a potential mess of red tape?
Can a replacement channel even be obtained?

Here are a couple of photos:
http://i133.photobucket.com/albums/q73/ ... 200055.jpg
http://i133.photobucket.com/albums/q73/ ... 200056.jpg

NO WELDING!! All parts of the assembly are aluminum. Yes, replacement parts are available. Try Air Repair (L-19), they used to carry reasonably priced parts. I thought that I had the contact info. but no got anymore!

When installing the new parts, reference the parts manual for the correct "U" bolt orientation. Some install "U" side up, which is wrong, "U" down is correct. Incorrect installation causes issues with cracking of the "U" bracket.

Is the broken part aluminum or steel? If it is steel i should think it could be welded. if aluminum, then no.

That is a common area for breakage. When I removed my spring I found a break almost exactly as you have pictured. I never noticed a problem prior to disassembly so gosh knows how long it was broken. I bought a replacement from a salvage yard. I have also seen them repaired with a patch an rivets but thats probably not going to satisfy the feds. Bill K

IPC Ref Fig 25 item #36 p/n 0510000-31 worth somewhere between 175-250 or possibly cheaper with no paperwork. This part often breaks when tail maintenance has been neglected. Bruce posted some tail pics sometime ago with a few field repairs. I've seen the tail piece missing and it didn't seem to be a big deal as long as the u-bolt and cross channel (item # 9 fig 29) where still able to keep the spring stack together.

The only other thing to look at is how many springs do you have installed? The reason I ask is that in your pic it looks like there's a very short spring/steel strip that shouldn't be there.

If memory serves, isn't the spring stack five in a C-170 and four in a C-170A and C-170B ?

c170b53 wrote:The only other thing to look at is how many springs do you have installed? The reason I ask is that in your pic it looks like there's a very short spring/steel strip that shouldn't be there.

4 springs, which I understand is correct for the alligator bracket.

There isn't actually a short spring there...what I think you are seeing is the area that was covered by the channel bracket/u-bolt and didn't get a fresh coat of paint like the rest of the exposed spring stack when the plane was painted a couple months ago.

minton wrote:Yes, replacement parts are available. Try Air Repair, they used carry reasonably priced parts. I thought that I had the contact info. but no got anymore!

Is that Air Repair the L-19/Stearman guys? Is the channel bracket the same on the L-19?

Oh sorry I stand corrected here, from the pic I thought it did look like another piece of metal that was fairly corroded, but now I see its the top leaf that's been there awhile with some new paint.

Fearless Tower wrote:

minton wrote:Yes, replacement parts are available. Try Air Repair, they used carry reasonably priced parts. I thought that I had the contact info. but no got anymore!

Is that Air Repair the L-19/Stearman guys? Is the channel bracket the same on the L-19?

Yes it is exactly the same other than the part number. I've bought three of them. These are commonly cracked or as yours has done, broken all the way off. Many don't realize it. This cracking may be because many install the clamp/bracket that surrounds this tab and the springs, upside down.

I remember the part being aluminum. If it were steal I would have welded the cracked parts I had. I don't have aluminum welding capability. The problem I see with welding is temperament of the metal and it will probably just crack again and won't take to long to do so. If ever there was a part that one could afford to have crack and completely break off, it is this tab. There doesn't seem to be much difference with or without it as is evidenced by the number I've seen with it missing.

Of course my comments on welding repair in the last paragraph throw legality to the wind.

Huh. Rick that is very interesting how your part doesn't have that cutout nor does the top piece have the tab. Wonder what parts you got? Here is the L-19 parts I got which are exactly like the 170 parts. I wouldn't worry Rick to be honest. Your parts are probably better off not having the tab that cracks and breaks off.

Very interesting Rick. My bracket was bought as an assembly part number 06421403. The assembly includes all the parts pictured below from the IPC figure. Like I said, I think you got the better bracket.