M20F Pictures Requested

[Vance Harral]

I spoke with Dan at LASAR today about this.  He said it shouldn't be necessary to remove the "baby shoe" bracket or do anything with the shim behind it.  New bolts and bushings should tighten things up and resolve the issue.  But, there are catches.  First, Dan said in his experience, part of the issue is slop between the O.D of the bushing, and the hole in the link the bushing goes into.  So, they are actually sending us slightly oversize bushings and recommending reaming the link to accept the larger bushing.  Furthermore, Dan says on one side of the link (can't remember if it's inboard or outboard side), it may not be possible to get the bolt out without at least partially removing the landing gear truss from the wheel well.

So, this seems to confirm my fears the fix is more of a "major" project than a minor one.  But what needs to be done must be done...  We've ordered parts and will start digging into it next week.

Edited January 29, 2018 by Vance Harral

[jetdriven]

I have the oversize bushings in the landing gear retract links. If the gear is down and locked and there is no lateral play (in and out) of the landing gear leg, then the bushings are probably OK. When they wear you get slop in that retract link and the gear clunks and the wheel moves when you attempt to move it inboard/outboard. Mine would move 1/8"   I cant see how a sloppy retract link makes the bolt too long where it hits the lower gear leg.

[jetdriven]

I have the oversize bushings in the landing gear retract links. If the gear is down and locked and there is no lateral play (in and out) of the landing gear leg, then the bushings are probably OK. When they wear you get slop in that retract link and the gear clunks and the wheel moves when you attempt to move it inboard/outboard. Mine would move 1/8". I got tired of listening to it rattle on taxi so I rebushed all of them when I rebuilt the gear.    I can't see how a sloppy retract link makes the bolt too long where it hits the lower gear leg.  But anything is possible i suppose.

[Vance Harral]

48 minutes ago, jetdriven said:

I cant see how a sloppy retract link makes the bolt too long where it hits the lower gear leg.

It's not a case of the bolt being too long.  It frankly doesn't matter how long the bolt is, because it's the nut that hits the landing gear truss, not the bolt threads.

My hypothesis (unconfirmed at this time) is that slop at the joint in question is allowing it to flex aft-ward as the over-center locks come into compression.  Such an aft-ward "bend" at the joint would move the castle nut closer to the landing gear truss with the gear in the down-and-locked position.  New bolts and bushings with tight tolerances should reduce the amount of fore/aft flex at the joint when it comes into compression.

[Vance Harral]

Right, but the landing gear truss that's being contacted isn't aligned with the axis of the bolt you're talking about, at least not in our airplane.  It's offset a little, such that the thing that hits the landing gear truss is the edge of the castle nut rather than the end of the bolt.  If it were offset just a little further, it wouldn't hit either the nut or the bolt.  A little less and it would hit the bolt first.  Might vary from airplane to airplane.

[carusoam]

Vance are you able to get a video of this while it is up on the jacks?

You might see what is happening better by going in slow motion or frame by frame.

probably tough to get video with everything in motion.  Do it safely first...

Best regards,

-a-

[Vance Harral]

Video is a good idea.  It will be mid-next week before I have the opportunity, though - once the airplane is in the shop and on jacks.  I'll report back here with progress.

[Vance Harral]

Decided to start a new thread for pics and video, with a more descriptive title and better tags for searching: