1989 M20J Left Main Gear "Play"

[Pixleyad]

Recently did a gear swing on 1989 M20J and noticed the Left main has about .5" of play in it. Both sides shock discs are secure and measure the same length. Any ideas on troubleshooting/adjusting the Left main to reduce play?

[N201MKTurbo]

We need more information.

Were is the play? Up/down, left /right? fore/aft?

[jetdriven]

If it’s left right, Often the retract  link is wearing out. Lasar has a kit that has an oversize bushing to fix this

[Pixleyad]

2 hours ago, N201MKTurbo said:

We need more information.

Were is the play? Up/down, left /right? fore/aft?

 

It is up/down. 

[N201MKTurbo]

Where is the play coming from? Is the play in the pivot bushings? Or is the shock disk center post moving up and down in the disks? If it is the pivot bushings, Call Laser and ask for all the bushings and nuts and bolts for your gear leg and change them out. I find that the bushings rarely wear that much, but the bolts do, so the first thing to do to save a few bucks is change out all the bolts.

[Andy95W]

4 hours ago, Pixleyad said:

 

It is up/down. 

@Pixleyad-

A friend of mine has a 62 M20C and both main gear have the exact same issue (I was not the one that signed off his annual).  I'm trying to help him figure out what's wrong with it.

Since only one side of yours is like that:  I suggest a comparison between left and right gear.  There is a definite possibility that either a spacer was left out or the attaching collar at the top was installed improperly. 

Regardless- please post the solution so I can help my friend fix his!

[Guest]

9 hours ago, Pixleyad said:

Recently did a gear swing on 1989 M20J and noticed the Left main has about .5" of play in it. Both sides shock discs are secure and measure the same length. Any ideas on troubleshooting/adjusting the Left main to reduce play?

With all of the possibilities, a short video clip would be helpful in figuring out the issue.

Clarence

[carusoam]

@Pixleyad

I thought a pic would be good...

But the doc requested a vid...

Can you comply?  Are you YouTube able?

post a link here if you can.

Best regards,

-a-

 

[Pixleyad]

Here's the video!

 

https://www.youtube.com/watch?v=fFGqatA7GQg&feature=youtu.be

[N201MKTurbo]

4 minutes ago, Pixleyad said:

Here's the video!

 

https://www.youtube.com/watch?v=fFGqatA7GQg&feature=youtu.be

You need new shock disks.

[Pixleyad]

17 minutes ago, N201MKTurbo said:

You need new shock disks.

Both left and right main discs measure the same length. The right side has almost no play. 

[N201MKTurbo]

16 minutes ago, Pixleyad said:

Both left and right main discs measure the same length. The right side has almost no play. 

Almost no play is too much. They should have no play.

You might want to check the bolt hole in the shaft and collar and see if they are wallowed out, but it is most likely just the shock disks.

What is the date code on your disks? 

[Oldguy]

And you may as well check the date on the nose wheel shock disks as well.

In for a ¢ in for a £.

[Andy95W]

@Pixleyad- please post a follow up when you get the new discs installed and bolts inspected.

Thanks in advance.

[carusoam]

@M20Doc video posted above as requested...

-a-

[Guest]

14 hours ago, Pixleyad said:

Both left and right main discs measure the same length. The right side has almost no play. 

From the maintenance manual here are the allowable limits under load, however when raised on jacks the shock discs should recover to a no play condition.  Yours don’t seem to recover and should be replaced.

Clarence

[Shadrach]

17 hours ago, Pixleyad said:

Both left and right main discs measure the same length. The right side has almost no play. 

Pixleyad,

It is likely time to replace the shock discs.  However, I would add that if the plane has been sitting for a long period of time in cold weather, the shocks can take time to expand.  I too am due for discs soon.  I too live and hangar my plane in Maryland.  There's a good chance that if you leave the plane jacked for a bit that they will recover.  I found out last winter when my plane sat from October to late February that discs will take a set if the plane sits for an extended period in cold temps.  After warming up my hangar with the plane on jacks the discs expanded to normal. The play disappeared and the discs could not be rotated this the suspension fully extended.

[cliffy]

If you have to replace the discs you don't need a tool for the mains. Just jack it  up and change them (look up my older post here)

For the nose gear you need the tool. 

[Pixleyad]

Thank you, all. We ended up rebuilding the left gear. I.e. taking the discs apart and putting it back together. The suspension was then tight and there was no play. I agree it’s getting to be time for the discs (dated 2009). We lowered the jacks and let the gear bear the weight for the night. Next day these was still no play. Looks like I will get another year!