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Safety your Tach Drive Cap!

Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
OK, I know that people have posted before asking how you safety wire the little Tach Drive cap on the back of the engine (at least, those of us using an electronic form of tach, so that we're not using a cable). Mine was one of those from Avery, and had a little hole in the "cap", but no way to safety the ring portion that actually threads on to the engine. I kind of figured "what's the point" of a piece of safety wire on the center post if it won't stop the ring/threaded portion from turing....right?

Notice I said that my cap "was" one of those from Avery?:rolleyes: Guess I'll be calling them in the morning! I took the top cowl off this afternoon to do a little pre-trip FWF check, and after almost 600 hours of flying, there was no cap. I knew it was tight last time the cowl was off a couple weeks ago, because I always check it. Ah well, it is somewhere on the ground somewhere, lonely and abandoned - hope it didn't hit anyone!

And the next one will be safetied, so that if/when it DOES unscrew, at least it will stay with the airplane!

Paul
 
You are not the first

Welcome to the multiple tach drive cover club!
After losing my first one, I did find a way to safety it that I believe will prevent the cap from coming off. Or, at least, as you said, stay with teh airplane!

Scott A. Jordan
N733JJ
675 hours
 
But...I thought

the TMX motor came with a back rubber cap that simply pushed over the threads?

Mibe did and..

a) hasn't come off and
b) I'm not sure if I care too much if it does.

Am I missing something?

Frank
 
Low tech Answer

Hi Paul,

I JB welded a drilled nut to the tach cover and then safetied it to the oil sender safety wire location. Has held up well so far.

2005065843184636097_rs.jpg
 
spruce

has a good one that will hold a positive saftey. put it on last week. had to make a tab for it to safety to however.
 
I bombed my cap somewhere at about 100 hours. Guess I am going to fall right out of the sky for not replacing it.

Seriously, they aren't needed.
 
AlexPeterson said:
Seriously, they aren't needed.
Click to expand...

You're really right - the drive is sealed. What's really funny is that my first thought was that I hate to have an exposed spinning thing there - and then I remember that I have that big orange SD-8 mushroom spinning away right next to it!:eek:

Paul
 
Are you guys tightening the cap by hand or using a pair of waterpumps? Out of all the tach cables I have ever seen connected and all the speedometer cables I have ever seen connected and all the tach covers I have seen connected, I have never seen one come loose and fall off. Did you put an O-Ring in the Avery model? Maybe that shrunk and the cap got loose? If tighten up with a pair of pliers I can't see how it could come loose..... maybe I am missing something
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
mahlon_r said:
Are you guys tightening the cap by hand or using a pair of waterpumps? Out of all the tach cables I have ever seen connected and all the speedometer cables I have ever seen connected and all the tach covers I have seen connected, I have never seen one come loose and fall off. Did you put an O-Ring in the Avery model? Maybe that shrunk and the cap got loose? If tighten up with a pair of pliers I can't see how it could come loose..... maybe I am missing something
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
Click to expand...

I did as you said and the tach drive cover is still on.

Today is 10-years since first flight. There are 2,052 hobbs hours since first flight.
 
mahlon_r said:
Are you guys tightening the cap by hand or using a pair of waterpumps? Out of all the tach cables I have ever seen connected and all the speedometer cables I have ever seen connected and all the tach covers I have seen connected, I have never seen one come loose and fall off. Did you put an O-Ring in the Avery model? Maybe that shrunk and the cap got loose? If tighten up with a pair of pliers I can't see how it could come loose..... maybe I am missing something
Good Luck,
Mahlon
Click to expand...


Good point Mahlon - I guess I figured that after 600 hours, it was on to stay....the new one will get a little more "persuasion"....(and a safety wire tether, which can't hurt!)

Paul
 
A dab of EZ Turn on the threads, a good turn with the pump pliers...and I expect it'll stay where I put it.
 
Well, I only have 85 hr on my engine, but

The little orange slip on thread protector covers is still on the fitting. I didn't know what to do with that connection, so just left the shipping cover on it.:eek:

Some one asked me the other day what gives with that shipping cover on the engine. I pulled it off to see what was under it and it looked like a set screw and I saw no oil leaks and the cover was not melted, so I slipped it back on and called it good.

If it does fall off I don't think anyone or thing will get hurt.:)

Kent
 
Ironflight said:
OK, I know that people have posted before asking how you safety wire the little Tach Drive cap on the back of the engine (at least, those of us using an electronic form of tach, so that we're not using a cable). Mine was one of those from Avery, and had a little hole in the "cap", but no way to safety the ring portion that actually threads on to the engine. I kind of figured "what's the point" of a piece of safety wire on the center post if it won't stop the ring/threaded portion from turing....right?

Notice I said that my cap "was" one of those from Avery?:rolleyes: Guess I'll be calling them in the morning! I took the top cowl off this afternoon to do a little pre-trip FWF check, and after almost 600 hours of flying, there was no cap. I knew it was tight last time the cowl was off a couple weeks ago, because I always check it. Ah well, it is somewhere on the ground somewhere, lonely and abandoned - hope it didn't hit anyone!

And the next one will be safetied, so that if/when it DOES unscrew, at least it will stay with the airplane!

Paul
Click to expand...

Paul,
I'm sure you can relate. I built racing cars and motorcycles for years and the saying was, "You don't have to safety wire everything, just the stuff you don't want to lose!" A simple and easy to remember thing. If you don't want it to fall off you better put some sort of positive lock on it.
Bill Jepson
 
A chunk of the SoCal crew spent the day with Paul & Louise for Paul's b-day today up at Big Bear. Now that the cat's out of the bag I can post this...our little joke b-day gift for him... :D

ironflight_gift.jpg


Thanks for the hospitality, guys!
 
dan said:
The one we got is machined aluminum.
Click to expand...

Actually, the one you got is not only machined aluminum, it is a work of art! (Of course, coming from Andair, that is to be expected...)

Oh, and the yellow tag is a work of art in itself - Thanks again guys!:D

Paul
 
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