Aileron control rod

[JimB]

I am in the process of upgrading my shafts and yokes and have run in to a problem. After installing them and leveling the yokes the rod going from the jackshaft to the aileron center bell crank isn’t long enough. Reviewing the different IPCs, there are multiple different part numbers for this rod and I am beginning to think that somewhere in the last 50 years someone may have installed the wrong rod. Does anyone know the differences between these PN rods? Does anyone know the dimension on this rod (PN 915033-000 Tube Assy or 915033-003 Tube)? Maybe there is a magic decoder ring for these rods??

Thanks

Edited October 9, 2020 by JimB

[cbarry]

This is just a thought, but is it possible that an adjustment has been in a joint somewhere upstream in the  rod linkage that unnecessarily reduced the overall length?

[JimB]

21 minutes ago, cbarry said:

This is just a thought, but is it possible that an adjustment has been in a joint somewhere upstream in the  rod linkage that unnecessarily reduced the overall length?

Thanks cbarry. That's exactly what I thought at first. I can tell you that when I removed the old shafts, the LH side control tube was shortened as far it would go and the RH side was extended as far as necessary to level the yokes. This would cause the center jack tube to rotate clockwise and allow the tube to work as installed. With the new shafts installed I had to shorten the control tubes to get them centered and level. Now the jack shaft mount is level with the yokes level (I think the way it should be) but the rod isn't long enough to adjust the center aileron bell crank to 1/16" left of center as required per the rigging procedure. So something is up. Maybe I am missing something but as much as everyone thinks Mooneys are complicated creatures, this is pretty straightforward. Just be nice to know how long that tube is supposed to be and then I could either check that off or source the right one. 

With yokes adjusted and leveled. Mount where control tubes attach to jack shaft from yoke shafts

Edited October 9, 2020 by JimB

[PT20J]

You could contact Mooney at technicalsupport@mooney.com and they should be able to look up the drawings and give you an answer.

From your description it sounds like something wasn’t quite right with the rigging before the change. I might go through the entire aileron rigging procedure.

Skip

[JimB]

4 minutes ago, PT20J said:

You could contact Mooney at technicalsupport@mooney.com and they should be able to look up the drawings and give you an answer.

From your description it sounds like something wasn’t quite right with the rigging before the change. I might go through the entire aileron rigging procedure.

Skip

Thanks Skip. I have contacted Mooney and Lasar. And I agree with you on going thru the entire procedure. When I got the replacement shafts in and saw that it was off that was the direction I went. The aileron bell cranks out in the wings are right (measuring the 4.3" from the spar web and ailerons are about even with the flaps. The center bell crank is correct and approximately 1/16" off of center and the yokes/shafts appear to be correct. Maybe I am missing something, but that control tube is the only thing that makes sense.

I was hoping someone had an old tube laying around or had their aircraft all opened up and could measure it for me. At least I could eliminate that. But if that's not what it is, I am really going to be scratching my head....

[JimB]

Just in case anyone wants to know, I got some information from Mooney. Tube PN 915033 measures 18.99" from the center of the fixed rod end to the end of the tube up until 1976. In 1976 the rod dimension was increased to 19.18". However, the PN did not change. I guess Mooney eventually recognized the problem I am having today. 

That .2 inches would make all difference for what I am doing. Anyone know where I can find a late model tube? All the ones I found searching are from early models. 

[Jetrn]

Baspartsales.com has one.  Call them directly they probably give you a better price then going to the ebay store.

[carusoam]

6 hours ago, JimB said:

Just in case anyone wants to know, I got some information from Mooney. Tube PN 915033 measures 18.99" from the center of the fixed rod end to the end of the tube up until 1976. In 1976 the rod dimension was increased to 19.18". However, the PN did not change. I guess Mooney eventually recognized the problem I am having today. 

That .2 inches would make all difference for what I am doing. Anyone know where I can find a late model tube? All the ones I found searching are from early models. 

Changing part dimensions without changing the part number... is foolish and incredibly serious at the same time...

In the case of GM, the same simple engineering mistake, was a crime cover-up...

In modern machine manufacturing... updating drawings and part numbers is really easy... 

Very few part designs last forever... from dimensions, to materials, to processes used, or coatings applied...

Complete traceability and interchangeability goes a long way...

For pre-flown parts... see if @Alan Fox has one... Or the other...

Best regards,

-a-