Rudder pedal play

[rturbett]

1980 M20J

Just got his report :

"recommended item : Excessive play in nose landing gear when rudder pedals are secured/ blocked"

Seems to me that there should be a measurement/ allowance.  (What's excessive?) What is the mechanism that allows play? slop in the connecting points of the linkages?

Thanks

Rob

[Ragsf15e]

1 hour ago, rturbett said:

1980 M20J

Just got his report :

"recommended item : Excessive play in nose landing gear when rudder pedals are secured/ blocked"

Seems to me that there should be a measurement/ allowance.  (What's excessive?) What is the mechanism that allows play? slop in the connecting points of the linkages?

Thanks

Rob

That’s a normal wear “point”.  Unfortunately, there are about 10 different parts, bolts, linkages in the nosewheel connection that can cause it.  Some are easy to find/fix, some not as much.  It needs to be on jacks with someone under the nosewheel wiggling it to find the worn area.

As far as I know, there’s no measurement.  Did you notice play in the steering when taxiing?

I had some “play” in mine noticeable in taxiing.  It was starting to get kind of annoying.  During the annual we found the worn bolt/bushing.  It wasn’t available from mooney right away.  My IA used a couple washers to tighten it up and it felt a lot better.  Meanwhile, I ordered the new parts which cost about $100 from lasar.  
 

If i was you, I’d ask them to identify the worn part and give you an estimate of time/cost to fix.  Then decide if you want to defer it because it doesn’t sound like an airworthiness issue in their eyes but it could be an easy fix.

Edit: I do think there’s a measurable limit for play between the rudder pedals and the rudder, but not the nosewheel.  Maybe someone else can show me wrong though.

Edited November 12, 2023 by Ragsf15e

[PT20J]

The nose wheel steering is not one of the strong points of the Mooney design. There is no spec on the play that I’m aware of. Blocking the pedals is part if the rigging procedure and not normally done during inspections.

If you are happy with it and your IA considers it airworthy then leave it alone. The worse that happens is that you have to do a lot of footwork to taxi straight. 

if you want to fix it, it’s fairly simple to put it on jacks and replace the parts with the most slop. In my case, I greatly improved it by taking it to an experienced MSC. They shimmed the steering horn and replaced a couple of rod ends. Didn’t cost much and it taxis much better now. 

Skip

[EricJ]

5 hours ago, rturbett said:

1980 M20J

Just got his report :

"recommended item : Excessive play in nose landing gear when rudder pedals are secured/ blocked"

Seems to me that there should be a measurement/ allowance.  (What's excessive?) What is the mechanism that allows play? slop in the connecting points of the linkages?

Thanks

Rob

I'd get whoever wrote that note to tell you what they'd replace or adjust or fix if you approved the work, i.e., where they think the play is coming from.    There's more than one thing that could be "addressed", and it may or may not help, depending on where any issue may actually be.

Do you have any trouble taxiing?   Does it make clunky noises sometimes?    If your airplane isn't having trouble, you can probably leave it alone.

There's a steering horn that can get sloppy with wear and can be improved with shims.   It's fairly easy to determine if the horn is sloppy, you can grab it and see if it wiggles around.  There are also steering rods with spherical rod ends that can wear and get sloppy.   There's also a potential issue with the front pucks mount as well.   There's also a certain amount of natural slop tolerance just due to how the thing is designed and how old the airplanes are.

Six+ years ago Maxwells did the PPI on my airplane and indicated that the steering horn was getting sloppy and was going to need a shim soon, but that it was okay for the time being.    I just reshimmed it this fall, so "soon" turned out to be quite a while. 

You can ask for clarification from the author of the note, and/or get another opinion. 

[rturbett]

Thanks for the sound advice!

Rob

[cliffy]

Google up "The 8 Second Ride" and read it. It describes what happens when the slop gets too big

If when on jacks and the nose wheel rotates more than just a few degrees left-right without and resistance its getting worn out. 

Most likely it is the conglomeration of joints at the top on the nose wheel well that is worn

They consist of Heim rod ends and bolts with bushings. They do wear out as they need lube and no one lubes them

They get washed real hard with wet runway operations

Secondly you will probably have loose rudder pedal bushings inside the cabin right at the bottom of the firewall where

the rudder pedal "axles" go from left to right across the cabin  After half a century they get loose and NEVER tightened up. 

You can only get to these by removing the cowl and then removing the smaller access panel at the bottom of the firewall.

It takes one mechanic to turn the bolts tighter from the firewall side while another (using a ground down 3/8 box wrench) 

holds the bolt from inside the cabin  Make sure they tie a string onto the 3/8 wrench in case (when) the drop it (they will). 

The large vertical nose wheel steering bolt (the thing the entire nose gear rotates on ) can be checked by jacking and pushing-pulling

on the nose gear to look for loose play. It and the bushing it rides in can be repaired 

[PT20J]

The “eight second ride” is about a nose wheel caster adjustment on pre-1977 airplanes that may not have been set up correctly at the factory. It is covered by SBM20-202.

[FoxMike]

When the steering horn gets worn out you can get enough play to cause the nose wheel to vibrate excessively (wildly).  This can lead to loss of control during landing.  No matter how skilled the pilot the airplane can easily end up in the weeds.  Best to get the problem solved before you end up in the weeds. Sometimes some shims will tighten the steering up but it usually takes a steering horn repair or replacement.

[PT20J]

Well, obviously if it shimmies, or directional control is compromised, it should be fixed. But that is something that will be obvious and doesn't come on suddenly. The OP wasn't complaining about steering issues but asking what to do about a notation that a maintainer made that the steering has "excessive" play. The truth is that they all have some play in them even when new because of the design and there is no spec on it and so how much is too much is determined by the owner and the maintainer.

[rturbett]

On the test flight, it felt "normal" but as I am just learning Moonies, not quite sure if it should be better than "normal". No control concerns, and definitely no shimmying in the limited time in plane.

Thrilled that the annual is getting done in lieu of a pre-purchase inspection. 

Rob