During some maintenance on the tailwheel I found that there was a lot of wear on the bolt attaching the springs to the fuselage. It appears to have "SPEC" stamped on the head of the bolt. The bushing is frozen to the bolt and shows a lot of ridging and wear. The bolt below the bushing is also worn pretty badly. I guess the question is what should I order when I get a new bolt and nut? Also, any leads on the bushing?
Can someone tell me the bolt and bushing specs? The plane needs to get the tailwheel fixed real fast as it appears to be awaiting a proctoscopic exam with its whole rear end exposed and up in the air. I guess I could put a blanket over it while not working on it to reduce the embarrasement.
Everett wrote:During some maintenance on the tailwheel I found that there was a lot of wear on the bolt attaching the springs to the fuselage. It appears to have "SPEC" stamped on the head of the bolt. The bushing is frozen to the bolt and shows a lot of ridging and wear. The bolt below the bushing is also worn pretty badly. I guess the question is what should I order when I get a new bolt and nut? Also, any leads on the bushing?
Can someone tell me the bolt and bushing specs? The plane needs to get the tailwheel fixed real fast as it appears to be awaiting a proctoscopic exam with its whole rear end exposed and up in the air. I guess I could put a blanket over it while not working on it to reduce the embarrasement.
What model 170 are we talking about? (don't know if it makes a
difference, just happen to be looking at a B model illustrated
parts page).
If it's the vertical bolt (that goes down through all 4 springs), it's
an AN6-22A (earlier 170s with 5 leaf springs use a -23A). The
original nut called out is an AN365-624 (nyloc) self-locking nut,
and I may get flamed for this, but you may want to opt for a
steel lock-nut. The bushing is a Cessna part (P/N 0442129-1).
Bela, there's nothing "wrong" with subtituting a AN363 for the AN365 nut but there's no advantage to it, and the all-metal nut will damage the threads on the bolt while the "nyloc" (elastic) nut won't and it will not have any more tendency loosen.
I disagree that the nyloc nut will hold it's torque as well as a steel
locknut in this particular application. The tailwheel (and supporting
structure) can take a hell of a beating (especially if you're landing
in the bush or on rough surfaces). I prefer a steel locknut
and if I have to, I'll replace the bolt now and then should I have to
take the tailwheel springs off for any reason.
