December 28, 2020 at 1:20 am #2798Danny AronhaltParticipant
Some months ago I sent my nose gear truss assembly to Lasar for overhaul because it had bent tubes from oversteering. I sent with it new lord bushings to install so they could take care of that for me as well. they reported that that could turn it around immediately if they sent me an overhauled one that they already had in stock with the turn stop STC in place.
When it came back I saw they had installed it with the shim in place that the SB for improved ground tracking called for. When asked they said they usually put this shim in because it can only help but I’m not sure that my plane needed it. Either way, we carried on.
Well, last week we measured the axle position per the datum in that SB and the axle is 1.5” behind the datum. The SB says to insert the shim if the axle is more that 0.6” in FRONT of the datum but there is no negative spec. My axle looks quite a bit further back than I’ve seen in photos of other Mooneys.
Checked the prop clearance and it is almost 10” from the pavement. So it’s on the upper end, which means without the shim it would probably be over 10”
We’ve done one landing and it tracked fine. But now I’m concerned that maybe the wheel is touching the wheel well on retraction. I think I see a small black mark in the top of the wheel well, but I’ve not had a chance to to put it back on jacks to check for contact there specifically. Now that I’ve seen this I’m wondering if this is making the last inch of J-Bar travel to the floor harder…takes some pushing but may be normal
Soon I’m going to replace the main shock disks which will raise the back and lower the prop some. That’s probably why the prop is so high
So the questions: Is my wheel too far behind the datum? Could it being this far back this far cause any issues? Should this shim be removed? Maybe it’s only needed with worn out shock disks?
I’d attach a picture but the max file size is too small.December 28, 2020 at 1:23 am #2799Danny AronhaltParticipant
1966 E model, SN 1126.March 16, 2021 at 4:28 pm #2972Mooney Technical SupportKeymaster
Great Question – First of all, I think you need to have the rigging checked to validate the 1.5″ behind the datum. As for the reconditioned part from another source, there could be many variables (does it conform to the Mooney Drawing for that specific S/N?) – You can email us at firstname.lastname@example.org and I will try and get you some more information if needed.
Best Regards, Frank
- You must be logged in to reply to this topic.