Stiff throttle cable

[rdv]

Hi,

The throttle cable in my 67-F is impossibly stiff in only the first quarter of stroke. Is it possible to lube and where?

 

Ryan

[danb35]

I had my throttle cable lubed at annual last year, but I'm not sure how they did it.  A technique I've heard involves a hose, some Tri-flow, and air pressure to force it down the cable.

[KSMooniac]

Liberal use of tri-flow all over the cable, perhaps with a helper exercising the cable while lubing.  You should also check for freedom of movement and make sure you don't have a mechanical issue with it too.

[rdv]

Tri-flow it is, thanks Scott.

[Peter T]

I am having an issue with a stiff throttle and prop control cables on ‘93 J. What was the successful procedure with the tri-Flo?

[Ragsf15e]

If possible, lube it like you’re asking.  However, I replaced mine with parts from the MSC in Oklahoma (very good service over the phone, best price).  Mine were 1968 original, so yours may have some life left.  My IA said they were kind of a pain to get properly routed and set for gear warning horn.  The individual throttle cable is around $600.

[RLCarter]

Replace them, had a t-cable go from a little stiff to locked up in 45 minutes. Stiff on start up, lubed with triflow, got better then locked up. 

[Prior owner]

One method is to remove the cable end from the fuel control, place a rubber hose over it and fill with lubricant, then force it through the line carefully with a little bit of shop air... my cable is covered with a plastic sheath, so no amount of triflow on the outside is going to help. Perhaps yours isn’t covered?

 

[Culver LFA]

@rdv if any work was recently done check the cable routing closely for excessively sharp bends, that’ll bind it up and no amount of lube will fix it.

[Pete M]

Sent mine to mcfarlane, had them duplicated...owner produced part...2something each...nice cables

[carusoam]

How many hours on the controls?

Some controls are getting swapped out at engine OH...

Nothing worse than stuck throttle or prop controls that are not at full power...

If you don’t find an obvious solution... Macfarlane is a great way to go...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Bob_Belville]

10 hours ago, Ragsf15e said:

I replaced mine with parts from the MSC in Oklahoma (very good service over the phone, best price).  Mine were 1968 original, so yours may have some life left.  My IA said they were kind of a pain to get properly routed and set for gear warning horn.  The individual throttle cable is around $600.

I did all three of mine myself - no big deal just route them where the old ones ran. The limit switch on the throttle is straight forward.

@$600 for one cable you paid "retail". McFarlane charged me $292 for the throttle and $322 each for the (vernier) mixture and prop (in 2015). 

[ArtVandelay]

I did all three of mine myself - no big deal just route them where the old ones ran. The limit switch on the throttle is straight forward.
@$600 for one cable you paid "retail". McFarlane charged me $292 for the throttle and $322 each for the (vernier) mixture and prop (in 2015). 

Are the cables identical between models?

I did mine as well, the throttle was the toughest, sharpest bend. Had to avoid the various avionics wires. I thought throttle was most expensive because of the limit switch cutout, mixture and prop are standard. IIRC the minimum radius of bend was something like 6”.


Tom

[Bob_Belville]

8 hours ago, ArtVandelay said:

Are the cables identical between models?

I did mine as well, the throttle was the toughest, sharpest bend. Had to avoid the various avionics wires. I thought throttle was most expensive because of the limit switch cutout, mixture and prop are standard. IIRC the minimum radius of bend was something like 6”.


Tom

Tom, I don't know if there's a difference between the E and the J cables. The IO 360 engines have different suffixes but I think that mostly about the counter-weighted crank in the J and the accessory pad, dual mags, so they should be pretty similar. 

I don't recall that the throttle was more trouble than the others though spaghetti on either side of the fire wall has to be dealt with. It would be a good idea to take pics of the routing before pulling the old cables. You'll want to know whether you need to go over or under wire bundles etc. Cables need to stay clear of the yoke linage movement. I should point out that I routed the cables and saved the control connections at the governor etc. for Lynn (A&P). He connected the business end and we verified full travel of each control.

In my case the vernier (typical on the mixture and prop) cost more than the limit switch slot. McFarlane offers a verier throttle as well as the standard tension lock.

https://www.mcfarlaneaviation.com/section/services/custom-engine-controls/

[mike_elliott]

Attach a 50# fishing line to the end of the old cable before pulling. Use it as a pull guide when putting in the new one. this will save you a bunch of time routing.

[Yetti]

when was it replaced last? are you able to fly the plane with a broken throttle cable is always a good question to ask.

[Ragsf15e]

Unless I’m wrong, mcfarlane will make an identical if you send yours, but won’t sell you a pma’d mooney one.  Have to get it through msc or Mooney... am I wrong?

[Bob_Belville]

1 hour ago, Ragsf15e said:

Unless I’m wrong, mcfarlane will make an identical if you send yours, but won’t sell you a pma’d mooney one.  Have to get it through msc or Mooney... am I wrong?

Close. I believe that they make the OEM cables for Mooney but when they sell cables direct it has to be under the "owner produced parts" provision of the regs. The buyer specs the cable either by filling out their simple drawing and signing it or by sending the old cable to McFarlane and instructing them to duplicate it. McFarlane provides the language your A&P will need for your logs. 

[warren.huisman]

Don't wait too long to replace the cable if lubricating it doesn't help.  Broke a throttle cable on a cherokee - fortunately on the ground.  Would have been a little too interesting if it happened in the air.

[Prior owner]

From what I can tell by looking at their catalog, I think they sell a PMA mixture cable only. All the other cables for a Mooney would be custom order, with no PMA.

 The PMA products are almost all Cessna, Piper, with one Grumman cable.

[Ragsf15e]

2 hours ago, PilotCoyote said:

From what I can tell by looking at their catalog, I think they sell a PMA mixture cable only. All the other cables for a Mooney would be custom order, with no PMA.

 The PMA products are almost all Cessna, Piper, with one Grumman cable.

Yep, it’s weird, but if you buy one from an msc or Mooney, it’s a mcfarlane though.  Just got legal by going through the manufacturer.

[Immelman]

Open your wallet, get a new one. Do the mixture too while you're at it. No its not cheap.

That cable doesn't owe you much more.

From a guy who had his 50+ mixture cable break.... when starting the airplane to warm it for annual.

Edited March 18, 2019 by Immelman

[Bob_Belville]

On 3/16/2019 at 10:43 PM, Ragsf15e said:

Yep, it’s weird, but if you buy one from an msc or Mooney, it’s a mcfarlane though.  Just got legal by going through the manufacturer.

Direct from McFarlane is perfectly legal. 

[mike_elliott]

6 minutes ago, Bob_Belville said:

Direct from McFarlane is perfectly legal. 

That begs the question of the liability trail. As an owner produced part, are you now accepting this role from both McFarland and Mooney?

who stayed at a Holiday inn express and can authoritatively answer?

[rbridges]

On 3/15/2019 at 10:48 AM, Peter T said:

I am having an issue with a stiff throttle and prop control cables on ‘93 J. What was the successful procedure with the tri-Flo?

I was using tri flow for mine, but I eventually threw in the towel and got a new cable from Maxwell.  My IA installed it.  From what I've read, the inner sheath starts getting worn.  Even after I lubed it, it was never as smooth as the new cable is now.