Question on Engine Mounts

[oldn0tded]

I'm looking for some group input.

The background:

1975 M20F, IO-360-A1A, 2810 TT, 900 TSMOH. Engine is sagging, starter does not touch, but the alignment is not correct. Engine mounts are roughly 30 years old. The current part is #J-9613-12 (all four), as listed in the engine logs.

Here's the question: Is there anybody out there that has looked at the parts manual (concerning engine mounts) and picked up on the idea of there being TWO different mounts specified? As in, since the engine "hangs" from the mount, the upper mounts are under a diffent stress load than the bottom mounts. A different mount is specified for the different locations. 

Part II: Is this a big enough question to lose sleep over? Apparently, it wasn't for the previous owner, and I haven't seen anything on this prior (and YES, I did search).

So, what does the group say???

 

Oldnotdead

[KSMooniac]

I just replaced my mounts on my J with Lord mounts. Same part number at all 4 locations, but the top ones go in the opposite direction from the lowers.

I expect the F is similar, but check your parts catalog and service manual.

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[Marauder]

I'm looking for some group input.

The background:

1975 M20F, IO-360-A1A, 2810 TT, 900 TSMOH. Engine is sagging, starter does not touch, but the alignment is not correct. Engine mounts are roughly 30 years old. The current part is #J-9613-12 (all four), as listed in the engine logs.

Here's the question: Is there anybody out there that has looked at the parts manual (concerning engine mounts) and picked up on the idea of there being TWO different mounts specified? As in, since the engine "hangs" from the mount, the upper mounts are under a diffent stress load than the bottom mounts. A different mount is specified for the different locations. 

Part II: Is this a big enough question to lose sleep over? Apparently, it wasn't for the previous owner, and I haven't seen anything on this prior (and YES, I did search).

So, what does the group say???

 

Oldnotdead

I have a 1975 F and at the last overhaul, part number 600155-503 were used on all 4 and described as Lord mounts.

Here is a thread on it:

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[Marauder]

BTW - I happened to help a friend load his engine from his J on a truck for an overhaul. The top mounts were mounted differently than the lower ones but they had the same part number on them.

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[Guest]

Usually the mount with the ring around it or step in the rubber goes on the compression side, ie on the back of the upper and the front of the lower.

Clarence

[oldn0tded]

Usually the mount with the ring around it or step in the rubber goes on the compression side, ie on the back of the upper and the front of the lower.

Clarence

I have noticed this "ring"....didn't know the significance...

It seems the same mount, J-9613-12, mounted with the "harder" side in compression is the way to go.

[oldn0tded]

"I have a 1975 F and at the last overhaul, part number 600155-503 were used on all 4 and described as Lord mounts."

 

Here is a thread on it:

Marauder,

The link didn't make the electronic voyage....

The parts manual that I have doesn't list the 600155-503 part number, but I think, after some research, that is the # Mooney puts on the Lord mount # J-9613-12....I think. Also, the part numbers I have in my manual might be for each HALF, and the 9613-12 number is for the assembly, I think. I'm spending some time on trying to make sense of a copy of a copy of a copy of a manual that appears to have been put together in the middle 70's.

I'm sure you know what I mean.....

 

Old not dead

 

[cliffy]

Changing mounts is not a real big problem. Do it one at a time. They are the same part # and are flipped for the compression side to be correct. Use a cherry picker to support the engine as they are all loosened at the same time but removed and replaced one at a time.. If new mounts don't cure all the sag you can shim the lower ones with a thick large area washer with a slot cut to the center the width of the bolt and slide it in when loose then tighten the bolts to the correct torque. There is a correct torque for the mount bolts so they can provide the correct shock absorption, I want to sat 30 foot pounds but I'd have to look it up to be sure.  

[Guest]

The 7/16" bolts through the Lord mounts are normally torqued to 450-500 inch pounds.

Clarence

[jetdriven]

...plus the running torque on the lock nut.  I couldn't get a torque wrench on it anyhow. 

[Piloto]

On the bottom mounts I installed an additional washer between the Lord and the engine to keep the engine from sagging as the Lords age. It worked very well after 7 years. The engine is centered with the cowling.

José 

[Alan Fox]

Where does the engine sit when it is running at 75% power twisting on the mount??

 

[Wakeup]

Dumb question??  How do I know I'm sagging?

[Andy95W]

Not a dumb question.  As always, Don Maxwell to the rescue!

http://www.donmaxwell.com/publications/MAPA_TEXT/Alining Engine Using Shims/ALIGNING_YOUR_ENGINE.HTML

[jamesm]

Not sure if this applies to you.. But years ago I learned that on my '67C with Lyc O 360-A1D  engine the nuts the holds the engine to the engine mounts comes in 2 sizes meaning that thread size were the same  but the wrench size had two different  sizes for the same part number. If I recall correctly  one was 11/16" and  the other 5/8".  I had  the larger wrench size nut  which  caused  enough interference with the nut  and the engine mount well  that it  took  me added effort and time to separate engine from engine mount. Had to make sacrificial  wrench to remove the engine from the engine mount.

Hope this helps.

James '67C

[Hank]

Dumb question??  How do I know I'm sagging?

If you can run without holding the waist of your pants, you aren't sagging.  

See The Don's article above to find out how to tell when your engine is sagging.

[Wakeup]

I have 99 problems but Sag is not one.  :)

[Marauder]

I have 99 problems but Sag is not one.  

It's purdy!

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