Governor

[chrixxer]

TrueSpeed in VNY is describing my old Garwin as a boat anchor; they'll overhaul it but the last one they did had the same problem I was having (fine on the ground and in level flight, slipped when you'd change pitch). I was going to IRAN it anyway, but with the metal in the filter following the intake lobes spalling, it needs an overhaul anyway.

 

So for about $1660 (incl tax) they can overhaul the Garwin, for $1855 I can put on a McCauley they've overhauled (or factory new, a bit over $2,000), or the PCU5000 which is more yet and the shop doesn't recommend (expensive overhauls when the time comes; there's a stud that wears out that can't be field serviced and has to go back to the factory?).

 

WWYD? I'm tempted to go with the overhauled McCauley (this whole thing is already more than expected...).

 

 

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[Vance Harral]

Faced with exactly the same advice from TrueSpeed a couple of years ago, we went with the McCauley.  I don't regret it, necessarily, but I also wouldn't call it a smooth experience.

First, the McCauley governor would not fit on our 1976 M20F with Lycoming IO-360-A1A, without grinding away a small portion of the housing of the governor itself.  Truespeed had no idea this would happen and they were surprised when I called them about the problem.  Since they didn't mention it to you, It appears they either don't remember that we had this problem on the same airplane/engine, or are choosing not to tell you about it.  I looked for photos I took at the time, but I am unable to locate them at the moment.  If you want to know more, I can get out to the hangar this weekend and take some pictures.  The portion of the governor housing that had to be ground away was small, non-structural, and we haven't had any problems with the governor in the two years since.  But it just seemed kinda ridiculous to have to take a grinder to a freshly overhauled and painted governor.  Truespeed was kind and straightforward in helping us resolve the problem, but they didn't offer us a discount or extended warranty on the overhauled McCauley due to our problem.

Second, if you go with the McCauley, make sure you get documentation from Truespeed regarding AD 2020-19-06.  The issue is not that Truespeed is going to give your a governor with a bad idler gear, it's just that it's another piece of AD paperwork you'll need to present to anyone verifying AD compliance in the future.

Giving up on the Garwin governor seemed like a no-brainer at the time, but if I had it to do all over again, I'd give more consideration to overhauling the Garwin instead of opting for the McCauley.  We actually still have the old Garwin core, and we're keeping it around "just in case".

 

[carusoam]

Hey! There’s been a Chrixxer sighting! 
 

Many have gone with the PCU device...

Mostly because it costs about the same as an OH on the existing device...

Modern construction, probably saves a pound too...

PP thoughts only not a mechanic...

Best regards,

-a-

https://mooneyspace.com/search/?q=Pcu5000&quick=1

 

 

[chrixxer]

Hey! There’s been a Chrixxer sighting! 
 
Many have gone with the PCU device...
Mostly because it costs about the same as an OH on the existing device...
Modern construction, probably saves a pound too...
PP thoughts only not a mechanic...
Best regards,
-a-
https://mooneyspace.com/search/?q=Pcu5000&quick=1
 
 

Is it a bolt-on replacement? I'd just as soon not grind parts. I remember reading about folks' positive experiences with the PCU5000 and now kinda wish I'd pulled the trigger back when this first came up; they've gone up in price a lot (IIRC they were about $1700 in 2019, and are about $2700 now(!)). (I'm not super concerned about the overhaul cost of the PCU; what's TBO on a governor?)


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[N201MKTurbo]

14 hours ago, Vance Harral said:

Faced with exactly the same advice from TrueSpeed a couple of years ago, we went with the McCauley.  I don't regret it, necessarily, but I also wouldn't call it a smooth experience.

First, the McCauley governor would not fit on our 1976 M20F with Lycoming IO-360-A1A, without grinding away a small portion of the housing of the governor itself.  Truespeed had no idea this would happen and they were surprised when I called them about the problem.  Since they didn't mention it to you, It appears they either don't remember that we had this problem on the same airplane/engine, or are choosing not to tell you about it.  I looked for photos I took at the time, but I am unable to locate them at the moment.  If you want to know more, I can get out to the hangar this weekend and take some pictures.  The portion of the governor housing that had to be ground away was small, non-structural, and we haven't had any problems with the governor in the two years since.  But it just seemed kinda ridiculous to have to take a grinder to a freshly overhauled and painted governor.  Truespeed was kind and straightforward in helping us resolve the problem, but they didn't offer us a discount or extended warranty on the overhauled McCauley due to our problem.

Second, if you go with the McCauley, make sure you get documentation from Truespeed regarding AD 2020-19-06.  The issue is not that Truespeed is going to give your a governor with a bad idler gear, it's just that it's another piece of AD paperwork you'll need to present to anyone verifying AD compliance in the future.

Giving up on the Garwin governor seemed like a no-brainer at the time, but if I had it to do all over again, I'd give more consideration to overhauling the Garwin instead of opting for the McCauley.  We actually still have the old Garwin core, and we're keeping it around "just in case".

 

Call these guys before you make any decisions:

https://westcoastgovernor.com/

 

[Vance Harral]

29 minutes ago, chrixxer said:

I'm not super concerned about the overhaul cost of the PCU; what's TBO on a governor?
 

We've had prop governors off the airplane twice in 17 years, both times due to oil leaks from seals in the governor case itself (not the seal between the governor and the engine accessory case).  It stands to reason that the seals go after a while, they are not particularly sophisticated.  In both cases we asked about IRAN only, but the shops we used (two different ones) stated that there was enough internal wear to warrant a full overhaul.  Back in the mid-2000s we just had the Garwin governor overhauled and reinstalled.  Got another 10-ish years out of it before it started leaking, and that's what led to the McCauley replacement.  You can judge for yourself whether 10 years and about 1000 hours is a typical run, and how to pro-rate the overhaul cost.

The thing that shied us away from the PCU5000 was not just that the overhaul was expensive, but that shops were already seeing these units come in for overhaul, enough to comment on the cost of parts.  My perception was that the PCU5000 was new enough that it seemed unusual that the shops were already seeing units needing overhauls.  That may not be a rational concern, though.  There are certainly operators that fly airplanes hundreds of hours per year, and that can rack up thousands of hours on equipment in relatively short times.

[Jim Peace]

Nothing like that new car smell........go with new if you can

almost everything up front is a SPOF...dont chance it...

 

[chrixxer]

On 3/20/2021 at 9:33 AM, N201MKTurbo said:

Call these guys before you make any decisions:

https://westcoastgovernor.com/

 

They're quoting $1275 + shipping for the McCauley (overhauled, I'm assuming, no core exchange). Think that's the route I'll go. 

[Flybeech21]

I have a PCU on my machine.  I changed between the Hartzell governor and the PCU a couple of times for troubleshooting purposes.  

In my opinion, the PCU is the better governor.  It requires a much lower volume of oil to do the job.  Also, it is a smaller governor so you won't need to utilize the access hole in the firewall to work on it.  

The people at PCU have helped me with customer support and troubleshooting from start to finish.  It was not a governor problem that I was chasing.  It ended up being a crankcase problem.  But, PCU never hesitated to help me with technical advise while I "chased the worm down the rabbit hole" for nearly a year.

You will be required to change the studs on the adapter plate when you change between PCU and factory governors...  So, you will have to remove the adaptor plate and replace studs when you change between the two.

It is not a small task to change governor types.  It is a pain in the arse and don't attempt it if you are not and A&P.  It requires making changes that are not detailed in installation instructions and require the installer to be competent.

Either way, go with the PCU.  

[Vance Harral]

On 3/24/2021 at 4:11 PM, chrixxer said:

They're quoting $1275 + shipping for the McCauley (overhauled, I'm assuming, no core exchange). Think that's the route I'll go. 

Guessing you've already decided on your course of action, but I finally got a fresh look at our McCauley governor and I remembered why grinding the case was necessary.

In many governor installations, the part of the accessory case that receives the governor has threaded studs installed.  The governor slides over the studs, then you install nuts to fasten the governor tight to the accessory case.  That is not the way it's installed in Mooneys, however.  Instead, the governor is installed with MS20074-05-14 bolts, which are a little over 1.5" long - see item #25 in the parts manual pic below.  The design of the McCauley governor is such that it is not possible to slide a 1.5" bolt through one of the four mounting holes, because of a protrusion on the case which I've marked with a red arrow below (I believe this is a pickup port for a prop synchronizer system).  So to install the McCauley governor, you must either swap the mounting bolts for threaded studs (unclear to me if this is "legal"), or grind the case protrusion just enough to slide the bolt in.

 

[J0nathan225]

 

On 3/27/2021 at 8:29 PM, Flybeech21 said:

I have a PCU on my machine.  I changed between the Hartzell governor and the PCU a couple of times for troubleshooting purposes.  

In my opinion, the PCU is the better governor.  It requires a much lower volume of oil to do the job.  Also, it is a smaller governor so you won't need to utilize the access hole in the firewall to work on it.  

The people at PCU have helped me with customer support and troubleshooting from start to finish.  It was not a governor problem that I was chasing.  It ended up being a crankcase problem.  But, PCU never hesitated to help me with technical advise while I "chased the worm down the rabbit hole" for nearly a year.

You will be required to change the studs on the adapter plate when you change between PCU and factory governors...  So, you will have to remove the adaptor plate and replace studs when you change between the two.

It is not a small task to change governor types.  It is a pain in the arse and don't attempt it if you are not and A&P.  It requires making changes that are not detailed in installation instructions and require the installer to be competent.

Either way, go with the PCU.  

where did you get this done/hours it cost?  I'm looking to go this route.  Currently in lower Alabama.  

Edited April 21, 2021 by J0nathan225
English language improvements

[Skates97]

15 minutes ago, J0nathan225 said:

do ya'll have a guestimate of shop hours to replace a Gerwin to PCU governor?  Shop initiall

where do you get this done/hours it cost?  I'm looking to go this route.  Currently in lower Alabama.  

I don't know what it is now or what the rates are in AL, but in June 2018 the shop here charged me 4.5 hours for a total of $450 to remove a Hartzell and install the PCU5000 on my D.

[J0nathan225]

56 minutes ago, Skates97 said:

I don't know what it is now or what the rates are in AL, but in June 2018 the shop here charged me 4.5 hours for a total of $450 to remove a Hartzell and install the PCU5000 on my D.

NICE!  That seems low though.   It looks fairly tight and with needing to change the bolts, I would imagine they need to fully decowl and tilt the engine forward?  I'm 100% ok with it being easier than I imagined though. 

[N201MKTurbo]

Just now, J0nathan225 said:

NICE!  That seems low though.   It looks fairly tight and with needing to change the bolts, I would imagine they need to fully decowl and tilt the engine forward?  I'm 100% ok with it being easier than I imagined though. 

You can do it in less than 1/2 hour without tilting the engine. The hardest part is the control cable.

[J0nathan225]

Going off of what @Flybeech21 said: 

 "You will be required to change the studs on the adapter plate when you change between PCU and factory governors...  So, you will have to remove the adaptor plate and replace studs when you change between the two.

It is not a small task to change governor types.  It is a pain in the arse and don't attempt it if you are not and A&P.  It requires making changes that are not detailed in installation instructions and require the installer to be competent."

I wasn't sure on a M20E, a place near me quoted 4 hours.  I thought that was low, but maybe not if nothing crazy needs to be done to get it out. 

[Skates97]

2 hours ago, J0nathan225 said:

NICE!  That seems low though.   It looks fairly tight and with needing to change the bolts, I would imagine they need to fully decowl and tilt the engine forward?  I'm 100% ok with it being easier than I imagined though. 

You only need the sides and top of the cowl off, the bottom does not need to come off. I took them off before taxiing over to the shop because I didn't want them doing it and it only takes me about five minutes to take it off or put it back on. And they did have to change the studs but as Rich said the engine does not have to be tilted.