Bent tailwheel steering arm

[WSHIII]

Here we go.

[bagarre]

Here's a shot of mine already taken apart.

BentSteeringArm.png

After looking at the chain guard and what it's supposed to do, I think my lack thereof was the cause.

Going around the pirouette, the chain slacked completely. I applied full opposite rudder to stop the turn, the slack chain probably caught under the shackle lip and wrenched the arm upward. That seems to be the most plausible explanation.

It's almost like the engineers knew it was going to happen and made the chain guard for a reason

I have some flat stock in the garage...one more owner made part

All painted and almost ready to go on. I even rounded off the spring edge so it doesn't chafe on the spring below it.

photo.JPG

[Bruce Fenstermacher]

Any suggestion where I can pick a replacement "heavy-duty" steering arm?

You already have the heavy duty arm for the 3200A or 3224A which is part 3214T. You might find a Scott part or Alaskan Bush Wheel (ABW). Lots of sources. Spruce, Univair and other suppliers as well as direct from AWB.

BTW if one has the straight arm and wants to upgrade the dust caps are different so you might want to order them as well. You might/probably be able to modify your caps as well.

[WSHIII]

Bruce

Any suggestion where I can pick a replacement "heavy-duty" steering arm?

You already have the heavy duty arm for the 3200A or 3224A which is part 3214T. You might find a Scott part or Alaskan Bush Wheel (ABW). Lots of sources. Spruce, Univair and other suppliers as well as direct from AWB.

BTW if one has the straight arm and wants to upgrade the dust caps are different so you might want to order them as well. You might/probably be able to modify your caps as well.

Yep, was going through the AKB website this morning for part number when I realized I already had the HD arm. Will give Nicole a call when they get in. Missed the part about David only having just a "standard" arm before.

Thank you.

[bagarre]

If you're going to pull it apart and replace the arm, consider ordering the Compression Spring, Dowel Pin, Main Bushing and three Grease Seals at least.
I'd tear down, clean and inspect everything before ordering tho. You might need other parts.

The ABW bush seals are rubber vs felt and work much better at keeping the grease in the wheel.

[WSHIII]

Yeah, I just went ahead and ordered the whole overhaul kit to go along with the new HD arm. Will be here Tuesday!

Thanks.

[DaveF]

Skip,

Is that steering arm steel or aluminum? It should be steel. I don't remember the details but some number of them were made of aluminum, which bent easily. My airplane came with a box of used parts, among them a bent aluminum T/W steering arm.

Dave

[WSHIII]

Dave,

I just assumed it was steel, and it looks like it but, I'll double check tomorrow and report back.

Et al. FWIW: I replaced the compression springs with the proper tension springs today. Then did a little pattern work and couldn't detect any real meaningful difference on the ground with the bent arm.

Skip

[buzzlatka]

Does the chain guard just attach directly to the bottom of the shackle? I don't seem to have one either?

[Bruce Fenstermacher]

It runs from under the bolt head underneath the bolt then underneath the nut. It makes the shackle one complete box so the chain cannot get caught in the bold area. Many 170s are missing this part. In fact I've seem some without the shackle all together.

chain guard.jpg

#16 is the chain guard. Easily made locally by owner.

[WSHIII]

Does the chain guard just attach directly to the bottom of the shackle? I don't seem to have one either?

I was able to purchased a new chain guard #16 from Univair. They didn't seem to have a new bracket #15 in stock.

[WSHIII]

Dave,

I just assumed it was steel, and it looks like it but, I'll double check tomorrow and report back.

Et al. FWIW: I replaced the compression springs with the proper tension springs today. Then did a little pattern work and couldn't detect any real meaningful difference on the ground with the bent arm.

Skip

Actually, I could have been a little more clear. I "couldn't detect any real meaningful difference MAINTAINING CONTROL on the ground with the bent arm." There is however a world of difference in the "feel". The new tension springs "feel" much softer, springier, more forgiving, than the compression springs. And in general, feels better. I think in my case, it was just a simple matter of the compression springs allowing me to overpower the steering arm.

[Bruce Fenstermacher]

#15 is also easily made same as #16. It does have a button or dowel which interfaces with a hole in the spring keeping it in place. This can duplicate with a rivet. Mine, which my partner made, uses a machine screw threaded through and cut to length to form the dowel.

tail wheel spring shackle.jpg

B model IPC part 0542108 item 15 fig 29

Material is steel .1" thick, .75" deep. It is bend 90° with an outside width of 1.828". The legs are 1.375" long. A .311" hole is drilled 1" from the top of the shackle. A AN-4 bolt is used so this hole is big. Probably for wiggle room. The dowel is steel and is .247" and sticks out .158"

tail wheel spring shackle guard.jpg

I'll add part 16 in a minute.
B model IPC part 0442125 item 16 fig 29

This is made of aluminum .019" thick. It is .75" deep, 1.8" wide outside the bends. The legs are .835" with a hole .257" to fit an AN-4 bolt drilled .5" from the top of the u shape. This part will not fit inside or outside the opposite part item #15 without bending. It will fit nicely with one leg inside and the other outside of item #15

To be accurate the parts pictured and measured above is for a l-19 part 0642108 and 0642125 and is likely the part you receive should you buy one.

[WSHIII]

Skip,

Is that steering arm steel or aluminum? It should be steel. I don't remember the details but some number of them were made of aluminum, which bent easily. My airplane came with a box of used parts, among them a bent aluminum T/W steering arm.

Dave

Steel.

[bagarre]

Ready to go on the airplane less one cotter pin. Before anyone says something, the cotter pin in the axle IS too short and is just there until I get to the field and pick up the right length from the shop.

FYI, When ordering the replacement parts, go ahead and order all new nuts, bolts, washers...everything unless you already have new stuff.

tw3.JPG

A shot of the home made chain guard and the STEEL lock nut holding the tailwheel on.
There is a history on this forum of tail wheel bolts working lose when using nylon lock nuts.

tw2.jpg

I have new chains and springs as well.