Replacing Citabria & Decathlon Trim Cables

[Bartman]

Hi all,

Has anyone replaced the trim cables recently? I'm wondering if I can use the old cables as fish wires to just pull the new wires through without having to remove interior panels. My A&P/IA friend is helping with the process but just trying to figure out what will be easiest for us before we start.

Thanks!

 

[Champdriver]

It's not the cable itself that's hard, it's the cable end fittings that have to pass between the pulley and the pulley guards.
Beyond that, I'm not sure how to do that fix. It's the upper pulleys that seem the hardest to reach.

 

[Bruce]

I’ll say no, pretty sure the End by control Handel will not go through the guide holes. I just installed new cables before covering and I think they go in one way. Frount to back Now if you pull a string or wire out with the cable to control handle seems like only pulley guides are in the tail where it Turns out of fabric and then under the tail where they split. I think you can get away with that. Remember the turn buckle will need to be straight when it hits the guide holes. I’d also suggest a second set of hands to feed it back in. Good luck

 

[Bartman]

Well, I'm going to give it a try so we'll see. The rear pulleys have to come apart anyway to be cleaned and lubed so we'll do one at a time and see how it goes.

 

[Vtailman]

I bet you could cut off the thimble end on the old cable and attach the new cable to it with tape and heat shrink…

 

[Bartman]

I was thinking of flattening the thimble and then using safety wire to link the thimble to the barrel of the turnbuckle. Something to condense the size of everything and hook them together.

 

[Bob Turner]

Why not just pull the cable and crimp the end on after it is in place? Crimpers should be easy to rent or borrow. The shrink tape trick will surely work then.

 

[Bartman]

I ordered pre-assembled cables from ACA.

 

[Bartman]

Oh yes you can use the old cable as a fish wire to pull the new one through! Pics when I do the second one tomorrow sometime.

 

[Vtailman]

Nice! How’d you end up attaching the old to the new?

 

[Bartman]

I’ll get pics tomorrow but safety wire and electrical tape

 

[Derek Lawless]

I’ll get pics tomorrow but safety wire and electrical tape

There’s not much you can’t do with a little safety wire and tape.

 

[Bartman]

The sidewall panel has to be up and out of the way


The cable starts with a thimble in the loop, get it out without mangling the cable too badly


Flatten the cable loop


The pieces barely fit through the eyelets in the formers so keep it all as tight as you can without damaging the threads of the new turnbuckle shaft.


The left rear window has a frame tube running vertically down the middle of it. Follow that tube down behind the sidewall upholstery and you'll find a plastic rub strip taped to the frame tube. The strip keeps the trim wires from rubbing against the frame tube. I very gently put a pencil under the tape to hold it open and then gave the bundle a little shove to get it through. From there it is clear sailing to the back of the fuselage using the old cable to pull the new one through. Don't mix up the cables and don't let them criss-cross each other! Put the turnbuckle on and attach the first one to the trim tab before pulling the other one through.



When you're all done, remember there is a cotter pin in the bolt that holds the trim lever in place so it can't back out during flight while remaining adjustable.

 

[Champdriver]

I keep forgetting that most of you guys have those modern planes. With my 7AC I have the upper pulleys at the top longeron, which is a bear to get to for lube and maintenance. I'm glad you found a way to fix this.