rear-mount governor bracket - how do I torque?

[skirting_virga]

The real answer here is mount the bracket before the engine, but I'm in too deep. My new governor is right up against the firewall and I believe I have to clip the safety wire on those screws to mount the bracket. Problem is, I have no idea how much torque to use when reinstalling them, or how to get a precise amount of torque through a flathead screw. Why the heck aren't they hex head?


Follow-up question. Assuming there's a handy solution to the previously-described problem - any tips for safety wiring in close quarters back there? There's a lot more apparent room in this photo than there is in reality. The firewall is fairly close.

 

[lr172]

Not sure anybody in the trade uses a torque wrench on a screw. Some practice on the bench while validating with a torque wrench, using a screwdiriver socket, until you teach your arm how to feel torque and learn the feel for each screw size.. No helpfull suggestions on the safety wire. I would have installed the bracket on the gov before installation. Consider safety wiring those as a right of passage. After 10 yqers, i still can’t safety wire on my 320’s sump strainer cap without 10 cuss words and a measurable amount of blood. Those days i wished i had my wifes hands.

 

[hgerhardt]

Seems much simpler to unbolt the governor from the engine and work this problem on a bench. If you're lacking that innate "feel" for torque on a screw, then you can get a torque screwdriver. Safety wire is also much easier while doing it on a bench, plus you'll be able to inspect it much better that way.

 

[tthrew]

If you are asking about the bracket for the governor cable, mine mounted to the studs that holds the gov. to the case - (nuts with torque seal in your pic) - it does not mount where the safety tied screws are. I’ve done this with the engine mounted, and as I recall, I had to loosen or remove all the bolts on the studs holding the gov on, so I could move the governor towards the firewall some, to get the bracket in place.

 

[skirting_virga]

Seems much simpler to unbolt the governor from the engine and work this problem on a bench. If you're lacking that innate "feel" for torque on a screw, then you can get a torque screwdriver. Safety wire is also much easier while doing it on a bench, plus you'll be able to inspect it much better that way.

I have a torque screwdriver so that's easy.

What's less easy is removal. I tried pulling the old one off and it wouldn't budge. Maybe there's a retaining ring on the spline? Should a new, newly installed governor be easy to remove? Maybe the old gasket was just sticky?

 

[hgerhardt]

I have a torque screwdriver so that's easy.

What's less easy is removal. I tried pulling the old one off and it wouldn't budge. Maybe there's a retaining ring on the spline? Should a new, newly installed governor be easy to remove? Maybe the old gasket was just sticky?

The gasket is apparently sticky. Apply radial pressure around the perimeter of the end of the governor to lever it off. Hopefully the gasket doesn't delaminate in the process. If it does and you need to replace it, be mindful of the screen which is part of the gasket; the bulge of the screen goes against the governor.

There is no retaining ring on the splined shaft.

 

[Desert Rat]

The torque for those screws is supposed to be 16 inch lbs +/- 1 inch lb.

It's more of a big deal to get the torque right in this application that on most stuff held together with flathead screws. Too tight and you can strip out the threads in the governor, too loose and the entire center of that thing is free to rotate. If you need to clock the arm to get proper relationship with the cable, loosening those screws and then rotating the inner assembly is how you do it.

Here's a link to a PCU5000 manual from one of the places that sells those governors. I can't verify if it's up to date or not, but you get the idea.

Aircraft Propeller Service Part Sales and Airframe Support

Line replacement units for commercial and military aircraft including 568F, 14SF, 14RF, and 247F aircraft. Airframe support for E-jets with stock items for Embraer E170 and E190 airframes.

www.aircraftpropeller.com

For measuring torque, a flat blade screwdriver bit that has a hex shaped back end will fit into a socket on your torque wrench. Usually a 1/4" socket. For safety wire, you're just gonna have so suck it up and make it happen.

edit- I don't remember for sure, but I want to say that's .020 safety wire? If so, it's a lot easier to work with in close quarters like that than .032.

 

[lr172]

The gasket is apparently sticky. Apply radial pressure around the perimeter of the end of the governor to lever it off. Hopefully the gasket doesn't delaminate in the process. If it does and you need to replace it, be mindful of the screen which is part of the gasket; the bulge of the screen goes against the governor.

There is no retaining ring on the splined shaft.

View attachment 101378

+1

It usually takes some heat cycles, but in general, those aviation gaskets stick pretty good. I just tore down a 360 and spent a crazy amount of time scrapping gaskets off. Be sure you have a spare gasket, as if you cannot easilly remove the gov, there is a good chance it will tear off some material around the bolt holes.