help ID this mysterious John Deere part

[dfkrug]

As I am about to button up the top of my JD 4300, I still have a
mysterious part that I found in the bottom of my main gearbox/
final drive housing. It was just lying in the oil sump.

Does anyone in the vast collective TBN knowledge base have any idea
what this is?

 

[radioman]

knockout plug from manufactring process ?

 

[Scooby074]

No idea what it is, but if i was to guess id say its a spacer of some kind. Looks like theres a circular wear pattern on the face of the disk.

 

[Gary Fowler]

Maybe it is part of the casting that they cut off during manufacturing process and it got left in the housing. Pretty poor quality control to leave something that big in a sump with gears and pumps. You are lucky it didnt get fouled up in a gear drive.

 

[WarrenF]

Is it magnetic??? If it is, I would suggest it is in there to attract and capture metal filings. I know that in many automatic transmissions in cars, there was/are magnets similar shape to that, that are there for that specific purpose.

 

[Iplayfarmer]

Is it magnetic??? If it is, I would suggest it is in there to attract and capture metal filings. I know that in many automatic transmissions in cars, there was/are magnets similar shape to that, that are there for that specific purpose.

That was my first guess.

Are you the original owner of this tractor?

Have you had it into a repair shop before now?

It looks like a piece trimmed off the end of a rod or something. I can see how something like that could get wrapped up in a rag, and then the rag used to plug an opening in the tranny housing during some work or something.

 

[dfkrug]

Looks like theres a circular wear pattern on the face of the disk.

Yes, if you look closely, you can see a partial circular pattern there. There
is no such pattern on the other side, but it has the same grinding scratches,
plus a tiny dimple in the middle.

My guess was that is was dropped into the sump during one of possibly
several times the top (rockshaft housing) of the gearbox has been opened
up. Either by the mechanic at the rental yard, or at the dealer. Maybe at
the manufacturer, too, but I think that is less likely.

Given the circular pattern on one side, and the dimple on the other, I was
guessing that the dimple was where the disc pushed up against a steel
ball, and the circular pattern was where a spring pushed from the other
side, as in a check valve. I do not see anything like it in any of the hydraulic
system parts diagrams.

BTW, it is steel and is attacted to a magnet, but it is not a magnet.

 

[dfkrug]

Are you the original owner of this tractor?

No, it is the Deere I have been rebuilding and chronicling here:
http://www.tractorbynet.com/forums/parts-repairs/146974-john-deere-4300-complete-rebuild.html

 

[Scooby074]

Are there any bores or shafts of the same diameter as the disk? might give you a place to start.

I was thinking it was up against a smaller shaft of the same diameter as the wear pattern, instead of a spring. Like a shaft moving fore to aft and rubbing on the disk at the extreme of its motion.I dont think check valve .It seems rather large for that.

If it was a official part, youd think it's be on a schematic somewhere. Hows your local deere dealer, maybe worth a trip to talk to one of the mechanics.

 

[Soundguy]

I've seen a part like that in the valvetrain on a volkswagon diesel rabbit while doing some head work with a friend... sure that didn't help any..

soundguy