Fixed the engine mounts...now I've got a cowl problem

Timbeck2

Timbeck2

Final Approach
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Timbeck2
For those who remember my "first annual" thread, you'll recall that I had to replace the two lower engine mounts as they were flat in comparison to a new mount. I'll tell you right now that the new mounts were the correct mounts as specified in the parts catalog and were the same brand and part number that came out of it. For those who haven't read that thread, 1970 Piper Cherokee 140 with the one piece nose cowl.

The flywheel has eaten through the top of the cowling. There is a hole about 1/2" in length and about 1/16" in width directly above the flywheel. As it sits on the ground and when I turn the prop, it doesn't rub at all which tells me it is doing it from vibration. Judging from the age of the hole, it has been doing this for quite some time but has only recently became a hole instead of what appeared to be a crack in the fiberglass which was noticed when I bought it.

I'm fairly certain that this can be easily fixed with new resin and fiberglass but that only fixes the symptom; not the cause. As far as I can tell there is no adjustment to be made on lifting the cowl up. I'm at a loss.
 
Did you replace only the two bottom mounts, or did you replace all four. I'd think about that for a while...
 
Only the two bottom. We had to take out all four of the mounts in order the change the bottom two. They are the correct part number/s and were installed according to the maintenance manual. What do you mean?
 
I think he means that you have two older mounts on top that could be moving enough to allow the flywheel to touch the cowl. Since I have no idea what the mounts cost, I wonder why you didn't replace all four since you had them off and had two that certainly needed replacing. Again, I have no idea the cost nor how you check to see if they need replacing.
 
My A&P made the call to replace the lower two since the rubber was cracked and were installed wrong. The top two were fine which was his call again. They were/are Lord mounts at $160 apiece.
 
Timbeck2 said:
My A&P made the call to replace the lower two since the rubber was cracked and were installed wrong. The top two were fine which was his call again. They were/are Lord mounts at $160 apiece.
Click to expand...
Sure, I would probably have done the same, but I wonder if the upper mounts may be weak and allowing the engine to move enough to contact the cowl. Really, I don't know, I'm just thinking out loud.
 
Timbeck2 said:
My A&P made the call to replace the lower two since the rubber was cracked and were installed wrong. The top two were fine which was his call again. They were/are Lord mounts at $160 apiece.
Click to expand...

My APIA is the same way on some stuff, this is one area I'd make a executive decision and tell him to replace all 4, long run it will be known good mounts all the way around, also will be less $$ then going back in later and replacing the other two.
 
Sure they're installed correctly? If it's a Dynafocal mount, the half of the shockmount asembly that has the circumferential ring molded into the rubber should be in compression. The ringed half should be in the top aft and bottom front positions. There may also be some heavy shim washers required that have been left out or put in the wrong places. The parts manual should be consulted.
 
As I said, the parts manual WAS consulted as well as the maintenance manual which shows exactly how the washers are stacked for each mount. The mounts are correct and correctly installed. This is the first annual I've had since I've owned the plane.
 
Is there a 140 type club similar to the Cessna 150/152 club you can consult? Might be your best bet if so...otherwise, sounds like you're buying two new mounts to round out the set. :frown3: OTOH, as someone with an ancient plane, new = good IMO.
 
Usually the Dynafocals have a bushing in the middle. It does not come with new Lord mounts . Are you sure its installed?
 
If the rubber mounts are correct and installed properly, that leaves either the lower cowl was made from scratch and sized to the sagging mounts (unlikely but possible), or the motor mount is tweaked probably from a hard landing. Either way, time to break out the measuring tape and compare to another.

Is the prop centered in the nose bowl?
 
This much trouble for a cherokee 140? We annualled my old one in a day.
 
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Take an angle grinder and reduce the diameter of the flywheel. To get it good & round, grind with the engine running.
 
Already did that with a file. It got pretty windy when I thought it wasn't going fast enough at idle.
 
Sorry about your troubles, airplanes are a PITA sometimes. Maybe a lot of time.
 
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