PCU5000 Governor Arm Clocking

[Ironflight]

I know I have seen this before but am not having much luck with the search function today.

I need to change the clocking on a PC5000 governor control arm by 90 degrees - can I do this by JUST removing the arm, or do I take the whole end off the governor (the 6 safety-wired cap screws) and re-clock that? It's the old theory - don't take apart any more than you have to - especially when you don't know what's inside!

Paul

[ChiefPilot]

Originally Posted by Ironflight

I know I have seen this before but am not having much luck with the search function today.

I need to change the clocking on a PC5000 governor control arm by 90 degrees - can I do this by JUST removing the arm, or do I take the whole end off the governor (the 6 safety-wired cap screws) and re-clock that? It's the old theory - don't take apart any more than you have to - especially when you don't know what's inside!

Paul

You can just loosen the six screws and rotate to an appropriate position. Don't remove the rear cover - loosening the screws should allow it to rotate. Easy peasy.

[Ironflight]

Thanks for the quick resposne Brad - but let me be clear - "loosen" the screws, or remove them and rotate the housing without removign it? Looks to me like I have to take the six screws out.

[BillL]

Originally Posted by ChiefPilot

You can just loosen the six screws and rotate to an appropriate position. Don't remove the rear cover - loosening the screws should allow it to rotate. Easy peasy.

Yep, and if you get curious, nothing (physical) jumps out! I had to remove my screws, too much rotation for the slots.

[ChiefPilot]

Originally Posted by Ironflight

Thanks for the quick resposne Brad - but let me be clear - "loosen" the screws, or remove them and rotate the housing without removign it? Looks to me like I have to take the six screws out.

You can pull the screws if there's not enough rotation available otherwise, but I thought removing the back was verboten. Perhaps I'm mistaken in this as Bill points out.

I do know you don't want to pull the arm off. I learned that the hard way when I popped it off accidentally while messing around with the prop control table. Since I didn't have the position marked on the splined shaft, I was rewarded with several hours of moving it (remove top cowl, clip safety wire, remove screw, reposition arm, re-install screw, re-safety wire, install top cowl, flight test - about 30 mins per iteration).

[RV8iator]

I had to clock one so far I ended up removing the plate completely and discovered 6 more holes positioned 30 degrees from the original position. I used them and everything was easy to get adjusted. The slots on the face plate covered them even after rotating to either end position.

[BillL]

Probably all done by now but here is more.

The cap of the gov (hartzell at least) just has stops, return spring etc, and all this cap does is position an internal stop axially, internally for the actual governor flyweight mechanism travel, thus the oil flow and speed.

The bracket can be located where you want, but then the lever arm has to be correct for the proper stroke. One issue: there is a boss on the housing that interfers with the rod end due to it's location on the housing side of the lever. This necessitates relocation (rechecking) of the lever and the housing. Your installation may vary.

IIRC, there is an o-ring seal so there is no issue with removal of the housing cap. It is not needed, but no harm if it is.

Picture to illustrate the clocking interference of the housing boss with the rod end. Note the control cable bracket in the background.

[Ironflight]

All good information guys. I think that tells me what I need to know to give it a shot. I think we'd have the same problem in re-clocking just the arm that Bill points out - there are bosses in the way of the rod end bearing. The interesting thing is that I didn't understand what "slots" you were discussing until I saw Bill's picture - that is different than the one we have. Here's a picture I found on the web of the same unit we are working on:



See? No slots! Must be an older design. I think this governor is 8 or more years old (new old stock thing).

[Mike S]

In the photo above, the outer ring is just a hold down, the inner section will rotate by loosening the outer ring.

[Ironflight]

Originally Posted by Mike S

In the photo above, the outer ring is just a hold down, the inner section will rotate by loosening the outer ring.

Ahh - now i get it....will adjust it next time I get down to that airplane project.

Paul