Gear puck inspection

[TheTurtle]

Question on the gear puck inspection.  According to the manual at static weight the puck can have a gap to the collar of 7/16" but on jacks it should be 0".

This hurts my brain.  Why would those specs be the case.  I would think with the plane on jacks you should have more not less gap to the collar.  

as an aside.  What was the shock on the gear for?  Why did they remove it?  I have the attachment point but its never had a shock and I vaguely remember reading on here there was an AD or SB to remove it.

Edited April 15, 2019 by TheTurtle

[N201MKTurbo]

With the weight on the gear, it pushes the collar up, When you put it on jacks, the weight of the gear pulls it down and the shock disks have to expand to fill the space. If they don't expand enough it fails the test.

BTW, if you wait long enough it will always pass the test. They just get slow when they get old. (don't we all)

[Marauder]

Just now, TheTurtle said:

Question on the gear puck inspection.  According to the manual at static weight the puck can have a gap to the collar of 7/16" but on jacks it should be 0".

This hurts my brain.  Why would those specs be the case.  I would think with the plane on jacks you should have more not less gap to the collar.  

as an aside.  What was the shock on the gear for?  Why did they remove it?  I have the attachment point but its never had a shock and I vaguely remember reading on here there was an AD or SB to remove it.

I think you are talking about the expansion of the discs. When the weight is off, they should expand. The shock was on early Mooneys as a way to dampen the nose gear oscillations. It was found not to help much and a service bulletin was issued with a 1.25 pound weight savings.

[TheTurtle]

i have no gap at the collar so I guess my 50 year old pucks are still good to go

[Hank]

27 minutes ago, TheTurtle said:

i have no gap at the collar so I guess my 50 year old pucks are still good to go

As long as the inspection was done shortly after jacking the plane up, and not after taking your lunch break or checking MooneySpace first . . . 

I replaced my vintage 1969 pucks in late 2012, and could not be happier (or more surprised!) by the improvement in taxiing and landing. It wasn't inexpensive, but it sure is nice! 

[Prior owner]

Now you’ve made me very curious, as those pucks are really old... when you jack the plane up and then set it back down, are the pucks compressing and expanding? I’m wondering if there is any movement of the strut at all.... it just really seems crazy that they at still within limits! Did the plane live on jacks for a long while?

Edited April 16, 2019 by PilotCoyote

[Marauder]

Where you really notice old pucks is on electric gear planes, with squat switches and nice cold days. You can’t get the gear up because the donuts which are already dried out to some degree, won’t expand to activate the switch.




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[Hank]

1 hour ago, Marauder said:

Where you really notice old pucks is on electric gear planes, with squat switches and nice cold days. You can’t get the gear up because the donuts which are already dried out to some degree, won’t expand to activate the switch.

That's what got me. Could put a space heater on them for a while, then that quit working. WV gets cold in winter . . . . Had no trouble the other seven months of the year.

[Sabremech]

 Be careful thinking the old pucks are still good. Much of the landing force will be transferred to the forward and aft trunion fittings. You may be causing yourself a very expensive repair by wearing out the aft landing gear fitting and the landing gear leg itself. 

My airplane has a ton of landings to go along with the 7600 hours of flight time and I have changed the landing gear leg with a used serviceable unit and am putting in a new aft bearing block. These are not cheap. 

David