Trim Jackscrew Binding

[takair]

1 hour ago, skykrawler said:

Here is a picture of the jack screw assembly removed from a 1982 J model.  After reading on this forum we removed mine for service.  The grease on the screw was cleaned and serviced and that made a difference.  The unit was opened by removing the plate on the left to service the interior grease.  But....no grease in here only light machine oil - MIL-L-7870. The shaft existed the housing moving to the left.  I could have been done the other direction by removing the link on the screw but that is massive safety wire.  The bearings are tapered roller bearings as depicted in the parts diagram (VII effectivities) and there are no shims.  The preload on the bearings seems to be function of a spacer between the bearings, which are pressed on, and the thickness of the paper gasket.  The assembly is cone, bearing, spacer, bearing code.  The blue plug on top is where oil is introduced after assembly, there is another on the side presumably for determining fill level.  The only top plug is accessible when the assembly is installed.   Only a few cc's of oil is needed.  You will likely find a piece of tape wrapped around the tube that holds the 'nut.'  I removed the tape to slide the shaft through the seal and discovered holes on the top and bottom.  The jackscrew retreats into this tube so potentially one could fully retract or extend the screw and inject some grease into the hole to get a more complete lube with the unit mounted in the tail.  Replace the tape since it presumably was put there to keep dirt and moisture out.

Interesting.  I think this is the first time I’ve seen a lube plug in one of these threads.  I wonder when that’s as introduced?  Sure makes things easier...

[skykrawler]

7 minutes ago, takair said:

Interesting.  I think this is the first time I’ve seen a lube plug in one of these threads.  I wonder when that’s as introduced?  Sure makes things easier...

The reason I posted is If you have a plug don't remove the assembly to clean the grease from the bearings....there is none.

[M20F-1968]

7 hours ago, skykrawler said:

The reason I posted is If you have a plug don't remove the assembly to clean the grease from the bearings....there is none.

When I rebuilt my 1968 F, the jackscrew was replaced with a new one taken from one of the unfinished Ovations on the factory line from when the factory closed in 2009.  I bought it through Russel Stallings shop in about 2010.

Any idea if my vintage jackscrew has the pictured lubrication plugs and uses oil and not grease.  

Did I interpret this correctly?

John Breda

[takair]

It’s odd,  I was looking to see if I could find the part with the lube plug, but can’t seem to find it.  Even in the Acclaim manual, it seems to call out Aeroshell 7.....at 100 hour intervals....which would be unreasonable without some provision for lubing.  I wonder if the lube plug was a mod. Someone added?  Has anybody seen it on their newer Mooney’s?  

[jetdriven]

I believe there's a pair of KP16 bearings in the older ones. Single ball deep groove roller bearing, they come pre-greased and they have little seals on them. We were greasing jackscrews with Aeroshell 7  but I think now they're starting to say you can use aeroshell 64

[skykrawler]

John B - are your asking about your old (vintage) assembly or the new one?

The 2003 M20J IPC depicts the alternate tapered bearings.  It does not depict the plugs.  It does list them as parts of the assembly (Plug filler port & site hole).   The part # for the VII effectivity assembly is 740230-502.  VII starts at s/n 24-1110.  I have no IPC for an Ovation.

The Aeroshell #7 is for the jackscrew.   The maintenance manual has nothing for servicing the bearings of the assembly.  The IPC has a note to shim so there is no more than .002 in endplay on the shaft.

Part # may be in the logbook.  Or, take the panel off and look at it - you might need a mirror.

[PT20J]

Maybe this will help...