Engine controls lubrication

[varlajo]

My engine controls are becoming very difficult to operate in cold weather, especially the mixture control. What is the appropriate winter lubricant and lubrication points? Haven't been able to find this info in my maintenance manual. I have a 71E with those silly levers.

 

 

[Ragsf15e]

Many of those are non lubricated.  If they’re getting real stiff, you’re likely in for replacement.  That being said, a very light silicone spray at each end where the shaft goes into the sleeve might buy you a little time.  Lubricant will attract dirt though and eventually it will get worse.

Mcfarlane for cables.  ~$600 for the mixture cable on my F.

[EricJ]

If it's a Bowden-type cable (wire wound over an actuator wire), you can rub graphite lube or tri-flow along the windings and flex the cable to work it into the center wire.   You can also put some graphite or tri-flow on the exposed end and work it back and forth to work the lube up the cable.    Tri-flow is probably less messy than graphite.

If it's not a bowden cable, but a typical control cable in a vinyl/nylon/teflon tube and sheath, they should generally not be lubricated.    If it is getting stiff it's probably telling you it's getting close to needing to be replaced.

https://www.aopa.org/news-and-media/all-news/2021/february/09/aircraft-maintenance-engine-control-cable-failures

It's a good idea to replace these sooner than later when they start acting up, as they can catch or jam on the parts that are disintegrating inside.   

[varlajo]

1 hour ago, Ragsf15e said:

Many of those are non lubricated.  If they’re getting real stiff, you’re likely in for replacement.  That being said, a very light silicone spray at each end where the shaft goes into the sleeve might buy you a little time.  Lubricant will attract dirt though and eventually it will get worse.

Mcfarlane for cables.  ~$600 for the mixture cable on my F.

Thanks. McFarlane appears to only carry controls for vernier-type designs. 

I suspect insufficient lubrication or something thermally seizing because the control works perfectly once the plane warms up a bit. 

[EricJ]

Just now, varlajo said:

Thanks. McFarlane appears to only carry controls for vernier-type designs. 

They make the cables for the quadrants, too.    I've replaced all three of my quadrant cables and they all came from McFarlane.   If they don't have a part number you should be able to use their OPP system.    I did two of mine using the OPP template and one with the Mooney part number (after they started doing that), and the OPP cables fit better.   

[Ragsf15e]

13 minutes ago, varlajo said:

Thanks. McFarlane appears to only carry controls for vernier-type designs. 

I suspect insufficient lubrication or something thermally seizing because the control works perfectly once the plane warms up a bit. 

I don’t know why they do this, but they do seem much stiffer in the cold as they fail.  I’ve had the same experience with mine when cold, but eventually they stopped “warming up” and I had to replace two of them.  I think they’re unlikely to improve much or for long without replacement.

[varlajo]

33 minutes ago, EricJ said:

They make the cables for the quadrants, too.    I've replaced all three of my quadrant cables and they all came from McFarlane.   If they don't have a part number you should be able to use their OPP system.    I did two of mine using the OPP template and one with the Mooney part number (after they started doing that), and the OPP cables fit better.   

Thanks, Eric! Reached out to McFarlane and LASAR. Looks like BAS Parts has a used cable, might as well snatch that one in case all else fails. 

[Ragsf15e]

16 minutes ago, varlajo said:

Thanks, Eric! Reached out to McFarlane and LASAR. Looks like BAS Parts has a used cable, might as well snatch that one in case all else fails. 

Even if mcfarlane doesn’t have them, they will make you one from the old one if that’s what you need.  It can count as owner produced parts.  They are pretty good at doing that easily.

[varlajo]

5 minutes ago, Ragsf15e said:

Even if mcfarlane doesn’t have them, they will make you one from the old one if that’s what you need.  It can count as owner produced parts.  They are pretty good at doing that easily.

Great, thanks for the insight! Waiting for them to respond.