348 mystery part on transmission magnetic plug

Hi, Just started my engine-out major today here in the UK, and after draining the transmission oil I found this on the magnetic plug. Also some black/grey sludge!.
Does anyone have any idea what it could be?
It measures 2.1mm thick when laid flat (Vertical height) I have had a look at the parts manual but can't see anything that resembles it.
Any help would be most appreciated.
Dave.
Image Unavailable, Please Login Image Unavailable, Please Login

 

Thanks for your fast replies guys.
The parts are metallic and were sticking to the mag plug.
I have dropped the lower cover plate and no apparant visible damage there. No side play on either shaft.
My son Josh was interrogating the net and ended up at the Superformance website. Circlip part number 113087. (supersedes 22804) The section looks very similar as does the diameter.

Item 22. here. It is called a gasket but I suspect that is the wrong description ?.
https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/348-group/348-1989-1992/lay-shaft-gears.html

The power unit is coming out next weekend and I will remove side covers on the transmission.
The funny thing is the speedo has always read approximately 33% lower. Maybe there is a problem at the sensor area??.
I will dive in and report back.
Cheers.

 

The cross section of the bits I found are square just like 113087. Do you have the dimensions of it to hand?.

 

Ok, I thought I had better update you all with my findings now the engine is out and transmission parted from engine over the weekend.
I removed the left hand side housing from the transmission housing to investigate as the parts on the magnetic plug resembled a sealing ring similar to that on the Supeformance site. Well, I was surprised to see that one was in place on the end of the shaft. It lives in a groove where indicated by the red arrow on the picture. Picture was taken after I removed the sealing ring.
I removed the sealing ring and measured it and it is identical in section and diameter. There is only one of these in the transmission, so the big question is how did they get there?.
Looking at the amount of wear on the faces of the one I removed from the shaft and comparing it to the bits I found on the mag plug, I would say that the bits I found lurking on the mag plug have not seen any mileage / use. Who knows, maybe done at the factory or subsequent maintenance gone wrong????.
I also noticed that the left hand side housing and intermediate plate have been removed in the past as there is white silicon sealant on the mating faces. This is not on the right hand housing joint. Maybe a previous oil change revealed pieces of the ring on the mag plug and the left side panel was removed then??.
The transmission filter had a small amount of aluminium (which I suspect are the first 3 threads of the missing dipstick threads in the casing) a few flat magnetic bits 2x2mm big and some white / grey silicone sealant and non magnetic grey / black sludge deposits on the internal floor of the transmission housing.
As far as I can see after removing the front intermediate panel between the transmission and engine, there does not appear to be any damage to any of the visible gear teeth. Next weekend I am going to flush out the transmission with petrol a few times and inspect with mirrors, magnets and remote micro tv camera. Hopefully I will find nothing.
Image Unavailable, Please Login

 

Well, I dove into the gearbox a little further on Thursday evening and was gutted to find play on the clutch shaft. Axial play was 4-5 mm and in one position it had rotational play. Felt like a gear tooth missing. That clutch shaft was coming out Friday afternoon so Friday morning I made a puller to do the job. Once clamped on, heat was applied around the bearing housing and the unit came out. Wow was I lucky to catch this time bomb early or what. The ring nut had backed off, the gear had moved forward and ate the gearbox casing slightly which is the result of all the grey black mud / sludge and aluminium in the bottom of the gearbox. Gear removed to find the splines were fully intact with no apparent wear. There gear has a tiny burr on the forward edge of the teeth where it ate the casing. The mating gear on the drop shaft is also in great shape with no apparent damage. I am going to replace the clutch shaft bearing as the forward part of the inner race had move forward causing the axial play on the shaft so loading the bearing unnaturally. Today I have removed the right side cover and thoroughly cleaned the gearbox out with avgas. A further inspection of bearings and gears will be done next week but all looks good at the moment. Tomorrow I am turning my attention to the engine, pre cleaning first and removing belts, cam covers and checking valve clearances. I will try and post some pictures tomorrow. Just one thing, when rotating one diff flange is the other side supposed to move in the same direction or opposite direction?. It acts like a non LSD diff. Is this normal ?. Oh and mileage on this 1992 348 is 15K. vin 91710. Bye for now.

 

yes, item 11