Any 348 speedometer gurus here?

Fired up the 348 last week after it had sat for a few weeks. During warmup I noticed the speedometer was occasionally coming to life and bouncing up to 40-60 mph, then going back to zero for a while, then repeating. Put a couple of miles on the odo just sitting still in the garage. You gotta admire a Ferrari's ability to break without even being driven...

After searching the archives here I decided to pull the cluster to check grounds, connections, etc. While it was out I went ahead and pulled the speedo to check its board and photo-document it in case a component ever burned beyond recognition.

Everything looked fine so I blew it out with canned air, put it back together, and set the assembly aside while I cleaned up the cluster. When I picked the speedo to install it in the cluster I noticed a small piece of copper lying in the inside of the rear speedo housing.

The problem is, I have no idea where it came from. There's nothing obviously amiss with the speedo itself. There are copper tabs that ride against the trip odo wheels, but this is not one of those-- it's a different size and shape. Everything *seems* to work okay in the trip odometer linkage. It bears no witness marks to indicate that it is either an electrical contact or a mechanical piece. I see no place in the speedo where it looks like such a piece would fit, but I'm unwilling to take it further apart to see it came from deep in the guts. As much as I handled the speedo while examining it and taking pictures it seems like this piece would have fallen out anyway.

I'm stumped, so I'm pinging you guys before putting it back in the car, in hopes someone here recognizes it. I know it's a long shot, but the collective knowledge of this group is amazing, so here's hoping...

The pic below is it sitting on a spool of .032" safety wire, to give you some size reference. Does anyone here know what it is, or have a disassembled speedometer that they can look at to see if it has one of these mystery bits?

TIA,

///Mike
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Mike, how's it going with this? My speedo quit recently and I changed out the sensor to no avail. The speedo is probably coming out tomorrow.

 

Hi Wade, thanks for asking. I gave up on figuring out where the mystery part went & reassembled the instrument cluster without it. But I have not driven the car since, so still no clue if the mystery bit is some much-needed integral part of the speedo or just an interloper. And obviously no help for your issue, other than a suggestion to check the round multi-pin connector on the left side of the frame near the damper.

I will be lighting up the car in the next couple of days to check out some new thermocouples so I'll have more for you then. Keep hoping the issue is a bad connection but starting to fear it might be the $ender. Got a good one you want to sell if it turns out I need one?

Best of luck finding the problem. I'll report back ASAP once I've run the car again. Should be soon. Would do it tonight, but don't want to scare the neighbors.

 

It's probably the speedo sensor.