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Dropped Pmag retaining bracket into accessory case

erich weaver

Well Known Member
Bad day. As i was reinstalling one of my pmags I dropped the aluminum retaining bracket and it disappeared through the mag hole I nto the accessory case. My heart sunk as I realized what I had just done. Reached my fingers as far in as I can to retrieve it but I can't feel it and I don't see it with a lighted mirror. Thinking it has likely dropped down into the oil sump and I will have to remove that to get it out. Does that sound like the right course of action?

Arrrgh!

Thanks for any words of wisdom you may have

Erich
 
Are you sure it's aluminum? Most of those blocks are steel I thought. Hopefully a magnet on a string will get it.
 
The retaining brackets are definitely aluminum so no go on magnet. I have a grabber tool but there is very little maneuvering room and obviously it's fishing around blind. Tried for awhile without luck.

Erich
 
That sucks. I did that with a Harley engine I was rebuilding. Had to take the whole freaking thing apart to get it. From that day forward, I stuff paper towls in *any* openings before I go near it. Good luck on your search and that sucks :(
 
If I remember correctly, there are 2 or 3 inlets for the oil screen cavity spaced pretty far apart. Take a look at a picture or diagram of the oil pan. If there is enough inlet volume remaining once blocked by the piece floating in there, you should have no major issues. There is a screen to keep that piece from being sucked in and your only risk is that part blocking the inlet and reducing oil flow. I believe the oil inlet channel running up the sump is 3/8"-1/2" diameter. That is the minimum area that you need for flow into the oil screen cavity, after accounting for current part blockage plus additional margin for other parts creating blockage.

The best answer is to pull the sum and get it out. I wouldn't expect it to take but a few hours to pull the sump and replace it. Don't forget to buy a new gasket before starting.

I would create a bendable rod with a 1" X 1" plate attached and start dragging the bottom of the sump with it. You should be able to find it and drag it to a corner where you can pick it up with a "grabber." The part can't bounce in the oil, therefore it should be within 3" of the aft wall of the sump.

Larry
 
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Learned this lesson the hard way too.

I approached the removal of my P-mags with the knowledge that a slip up might result in loss of something into the case. Then I made my first mistake. I removed the bottom clamp first. While removing the top clamp the mag suddenly dropped and the clamp was lost into the great oily void.

I was able to retrieve it with only modest effort. Drain the oil then inspect the case with a flexible inspection scope borrowed from a friend. I spotted the clamp partially obscured in the bottom of the pan nearly straight down. Using a spring fingered grabber I positioned the clamp so that I could stick the grabber with prongs held together through the hole for the mounting stud. I released the grabber opening the prongs and the clamp was mine!

Try this before considering any disassembly. I now religiously leave the bottom clamp tight until the top clamp, washer and nut are safely on the work table. Of course when reassembling, attach the bottom clamp first.

Good luck
 
Ive done something similar. Best bet is to drain the oil and see if you can shake the piece down to a lower sump plug. If you can do that, grab it with a loop of safety wire (not a hook, a loop, so it cant come off). Next step is to work a piece of stiff wire from under the engine, through the drain plug and out the mag hole. Attach the free end of the safety wire to the stiff wire securely, then withdraw the whole mess from the mag hole.
 
Not sure of the shape of the bracket but if it has flat side I would try sucking it out with 1/4" rubber or plastic hose. Hook the hose up to a shop vacuum and fish it down, you may just luck out and have it land on flat side of piece and maybe carefully lift it out.

Maybe a dumb idea but I'd try it depending on shape of piece.
 
Missing parts

If nothing else works I would remove the dipstick tube before pulling the sump. It's a good sized hole to look thru and with a flashlight and small mirror or a Boroscope you should be able to see all of the bottom of the oil sump.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
good tip

Lots of good advice here, I can only offer my appreciation for you telling this story, since I'll be pulling my p-mags in the coming months for an upgrade, and this kind of thing never occurred to me. Great tip to remove the top first, then the bottom.
 
Well none of this is working for me. The inside of the sump is a complex shape with all the intake tubes and it's difficult to maneuver the borescope around in there and have any clue which direction it's actually looking. No luck with random groping with the pronged grabber tool.

Gave up on retrieval and started pulling stuff off the bottom of the sump to prepare for its removal - FAB, AFP throttle body, throttle body bracket, control cables. Ugh. Gonna be more than a few hours to get the job done. Will jump back on it tomorrow; I've done enough damage for today.

Thanks everyone. Hard lesson learned - don't be messing around installing or removing the top Pmag retention bracket without the Pmag in place. Bad things can and do happen!

Erich
 
Well none of this is working for me. The inside of the sump is a complex shape with all the intake tubes and it's difficult to maneuver the borescope around in there and have any clue which direction it's actually looking. No luck with random groping with the pronged grabber tool.

Gave up on retrieval and started pulling stuff off the bottom of the sump to prepare for its removal - FAB, AFP throttle body, throttle body bracket, control cables. Ugh. Gonna be more than a few hours to get the job done. Will jump back on it tomorrow; I've done enough damage for today.

Thanks everyone. Hard lesson learned - don't be messing around installing or removing the top Pmag retention bracket without the Pmag in place. Bad things can and do happen!

Erich


Sorry for your troubles. Most of us have done something really boneheaded at one time or another.
 
If I remember correctly, there are 2 or 3 inlets for the oil screen cavity spaced pretty far apart. Take a look at a picture or diagram of the oil pan. If there is enough inlet volume remaining once blocked by the piece floating in there, you should have no major issues. There is a screen to keep that piece from being sucked in and your only risk is that part blocking the inlet and reducing oil flow. I believe the oil inlet channel running up the sump is 3/8"-1/2" diameter. That is the minimum area that you need for flow into the oil screen cavity, after accounting for current part blockage plus additional margin for other parts creating blockage.

The best answer is to pull the sum and get it out. I wouldn't expect it to take but a few hours to pull the sump and replace it. Don't forget to buy a new gasket before starting.

I would create a bendable rod with a 1" X 1" plate attached and start dragging the bottom of the sump with it. You should be able to find it and drag it to a corner where you can pick it up with a "grabber." The part can't bounce in the oil, therefore it should be within 3" of the aft wall of the sump.

Larry

In reference to your first paragraph Larry, the real danger if the piece doesn't settle into the sump is that it bounces around in the accessory case and jams a gear - the engine would come to a sudden stop pretty darn quick! The BEST case is that it falls into the sump and can be retrieved by pulling it. Regardless, don't run the engine until it has been positively removed.

Paul
 
In reference to your first paragraph Larry, the real danger if the piece doesn't settle into the sump is that it bounces around in the accessory case and jams a gear - the engine would come to a sudden stop pretty darn quick! The BEST case is that it falls into the sump and can be retrieved by pulling it. Regardless, don't run the engine until it has been positively removed.

Paul

Sorry, should have been more cautious here. I assumed that he examined the gear area well. The mag hole is pretty big and I assumed he carefully examined that area as you have a pretty good view through the hole. The piece could only realistically have fallen on the Crank / Cam idler gear interface on the left and the same plus the governor gear on the right. If it were resting on those gears, it should be pretty visible with a mirror and flashlight. The OP indicated that he used those tools in his examination.

Larry
 
How about an update: Did you get the sump off? Have you/can you mount the mag with the sump still removed? I feel your pain, but I know that doesn't help much.

regards
~Marc
 
In reference to your first paragraph Larry, the real danger if the piece doesn't settle into the sump is that it bounces around in the accessory case and jams a gear - the engine would come to a sudden stop pretty darn quick! The BEST case is that it falls into the sump and can be retrieved by pulling it. Regardless, don't run the engine until it has been positively removed.

Paul

I have to agree with Paul. In an auto engine I would not worry about it but and airplane, no way I would leave it in the sump. My bet is that it is in the accessory section.
 
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