gear motor/tranny spring missing

[Richard Haupt]

I am getting close to my first annual since purchasing my 180 and have been snooping around my plane in preparation of the annual. Having bought and watched the gear overhaul video, I've noted that the motor/tranny spring is missing. And, I don't see an attach point on the floor as in the video. In the video it appeared that a cotter key went through a hole and the spring attached to the key. I see the hole on the motor/tranny arm where the spring attaches to there. This plane was maintained for many years buy a reputable shop in Florida, and I am surprised to find the spring and attach point missing. Or am I missing something??? I would think this is a critical "safety of flight" issue should a manual gear extension be needed.

My question: Do I simply drill a hole in the rim of the access hole and install a cotter key, then install the spring to the key? If so, how far forward of the motor arm hole where spring hooks to? Or is that not critical? I have the spring and it is pretty robust, so I can't go far from the other spring lower attach point...thanks.

[Kristin Winter]

On the older Comanches, it is typical for the spring to be located to the right side of the transmission/motor assembly, attaching to a cotter pin coming up through the floor to the right of the small, thin access door.

[Don Nelson]

Richard, You're nowhere near alone in finding that spring, cotter key, and even the hole in the floor panel missing. We really stress inspecting for those in our CPPP classes.
My current and the most previous Comanches were missing it all. Don't know about my first 250 Comanche, back in the late 60's before becoming aware of the issue.

BTW, in installing the assembly in my last single, after drilling the hole I found attaching the spring to the transmission arm and the cotter key, then poking the key thru the floor, determining a suitable length of the key before bending its ends flat onto the floor, worked for me.

Best regards,
Don

[Pat Elliott]

What service bulletin number is this?

[Don Nelson]

Good question Pat, tho I'm not aware of an SB on it.
Don

[Richard Haupt]

That's not terribly encouraging that the spring, drilled hole, and cotter key are missing on other Comanches too. I will look on the right side as recommended this weekend, but if not found I'll install what I need to on the left side.

When missing, I wonder what the odds of a failed emergency gear extension to be due to the motor/worm gear not popping up from spring tension? Maybe I don't want to know...Thanks.

[Zach Grant L1011jock]

There is a big hole in the release lever that you should put your finger through and pull up vigorously once the lever has been pushed full forward through its full travel. This does two things. If it doesn't pull up, it hasn't released and you won't get the gear down manually so you need to try again, and if it does pull up, you are clearing the mechanism out of the way ensuring a restriction free free fall of the gear.

Zach