Trim indicator not moving reliably F model

[bixmooney]

Question about my trim indicator arrow on 75 F model

the indicator does work but it does not move continuously with every turn of the trim wheel.   
it is well above the take off indicator after landing and then u want to trim back down to just above the white take off indicator line , but find I have to go past it and then back up. 
 

Is this a lubrication issue or a broken cable , kinda doubt it is broken.   Wondering where I can get to it to use penetrating oil on it. 
 

 

[Shadrach]

Unlikely broken. More likely the the cable either needs to be lubricated or is not properly secured causing the cable to “bow” rather than move the indicator. Imagine if you ran derailleur and brake cables on a bicycle without securing the cable housing to the frame? You need to ensure that cable movement at one end of the housing translates to equal movement at the other end of the housing. 

Also, ensure the cable is not slipping at its attach point at the jack screw or at the indicator. I would start at whatever side is easiest to access.

[M20F-1968]

The earlier models had a threaded end that installed into the moveable block in the trim wheel assembly.  That was/is an expensive cable.  By 1975 t I think mooney went to a solid cable captured by a set screw.  Take it apart, inspect, remove the cable, soak in in penetrating oil, clean it, then re-lubricate it with Triflow, install it, adjust it, and lubricate it again.  Everything needs to work easily.

John Breda

 

[Vance Harral]

38 minutes ago, M20F-1968 said:

By 1975 t I think mooney went to a solid cable captured by a set screw. 

There is no set screw that I recall, at least not in our 76 F model.  My recollection is that the little white plastic trim indicator is not attached to the cable except by compression fit.  if you remove the transparent cover plate that covers the indicator (just conventional screws to do so), you can slide the indicator up and down on the cable with your fingers.  Not easily, but with some force.  Having said that, it's possible there is indeed a set screw in the indicator that I don't recall or didn't see, and I was just brute-force sliding it.

Regardless of whether there's a set screw or just compression fit, if the indicator gets hung up in its sliding track somehow, moving the trim wheel in the nose down position will simply pull the cable out of the indicator.  The indicator may later vibrate loose out of whatever is causing it to hang up in the track.  If that happens, then rather than being secured to the cable, the indicator rides on top of it.  This "sorta" still works, except that now (1) the indicator indicates more nose up trim than you actually have; and (2) as it gets hung/unhung in the track, it can exhibit the kind of random hysteresis @bixmooney is reporting.

42 minutes ago, M20F-1968 said:

Take it apart, inspect, remove the cable, soak in in penetrating oil, clean it, then re-lubricate it with Triflow, install it, adjust it, and lubricate it again.  Everything needs to work easily.

Sound advice.  But when we had this problem, there was nothing wrong with the cable and its housing, and no need to remove and lubricate the cable itself.  The only "hangup" was the little white trim indicator itself, and the track it rides in.  Some fibers and grime had gotten into the track over the years, causing it to bind up.  After cleaning and lubricating the indicator and track, all was well.

[Shadrach]

59 minutes ago, Vance Harral said:

There is no set screw that I recall, at least not in our 76 F model.  My recollection is that the little white plastic trim indicator is not attached to the cable except by compression fit.  if you remove the transparent cover plate that covers the indicator (just conventional screws to do so), you can slide the indicator up and down on the cable with your fingers.  Not easily, but with some force.  Having said that, it's possible there is indeed a set screw in the indicator that I don't recall or didn't see, and I was just brute-force sliding it.

Regardless of whether there's a set screw or just compression fit, if the indicator gets hung up in its sliding track somehow, moving the trim wheel in the nose down position will simply pull the cable out of the indicator.  The indicator may later vibrate loose out of whatever is causing it to hang up in the track.  If that happens, then rather than being secured to the cable, the indicator rides on top of it.  This "sorta" still works, except that now (1) the indicator indicates more nose up trim than you actually have; and (2) as it gets hung/unhung in the track, it can exhibit the kind of random hysteresis @bixmooney is reporting.

Sound advice.  But when we had this problem, there was nothing wrong with the cable and its housing, and no need to remove and lubricate the cable itself.  The only "hangup" was the little white trim indicator itself, and the track it rides in.  Some fibers and grime had gotten into the track over the years, causing it to bind up.  After cleaning and lubricating the indicator and track, all was well.

I think John is talking about the jack screw end of the cable under the floor.

 

[M20F-1968]

On 9/4/2024 at 6:53 PM, Vance Harral said:

There is no set screw that I recall, at least not in our 76 F model.  My recollection is that the little white plastic trim indicator is not attached to the cable except by compression fit.  if you remove the transparent cover plate that covers the indicator (just conventional screws to do so), you can slide the indicator up and down on the cable with your fingers.  Not easily, but with some force.  Having said that, it's possible there is indeed a set screw in the indicator that I don't recall or didn't see, and I was just brute-force sliding it.

Regardless of whether there's a set screw or just compression fit, if the indicator gets hung up in its sliding track somehow, moving the trim wheel in the nose down position will simply pull the cable out of the indicator.  The indicator may later vibrate loose out of whatever is causing it to hang up in the track.  If that happens, then rather than being secured to the cable, the indicator rides on top of it.  This "sorta" still works, except that now (1) the indicator indicates more nose up trim than you actually have; and (2) as it gets hung/unhung in the track, it can exhibit the kind of random hysteresis @bixmooney is reporting.

Sound advice.  But when we had this problem, there was nothing wrong with the cable and its housing, and no need to remove and lubricate the cable itself.  The only "hangup" was the little white trim indicator itself, and the track it rides in.  Some fibers and grime had gotten into the track over the years, causing it to bind up.  After cleaning and lubricating the indicator and track, all was well.

The other thing that occurs is that the cable (solid wire) which is just melted into the plastic comes loose.

John Breda

[Yetti]

You can unscrew the plexiglass cover.   Clean out the gunk.   Check the tightness of the indicator (piece of plastic) on the Bowden wire.    Make a new one out of a plastic cutting board from wally world and put it back together.

[bixmooney]

4 hours ago, Yetti said:

You can unscrew the plexiglass cover.   Clean out the gunk.   Check the tightness of the indicator (piece of plastic) on the Bowden wire.    Make a new one out of a plastic cutting board from wally world and put it back together.

That is on my agenda ! 

[M20F-1968]

You can make new sliders with nutplates holding the wire to the sliders.....

John Breda