I've searched the internet and can't seem to find what size the particles are from manual transmission wear.


The iron particles from the gears and bearings will eventually be trapped by the magnet, so they may not be as important, but the particles from the synchros will constantly be in suspension.


Anybody know how big the particles are?


thanks

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I would guess that after break in they would be extremely small, until the unit began to fail. While breaking in you are wearing the little ridges left by machining, during most of its life the pieces have mated wear patterns so not much gets knocked off (assuming good lube ) but when failure begins the surfaces begin to shed little chunks, small but bigger than any other time. If you are concerned, run the unit for a while to get it broken in then change the lube (and clean it thoroughly) and refill. the brass from the synchros is much softer than the iron so I personally would not worry about it there. The problem is that while cleaning it out you are likely to introduce more debris than you remove.

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Dave

1977 d-200 crew cab ex-army pickup wants it's /6 back
1962 Valiant 2 door, 170, three on the tree
1972 d-100 parts truck
80 volare wagon now a parts car

The brass should not be an issue for operation. I can't recall ever seeing anything more than what I would call 'mote' sized (like dust particles or tiny flakes), if all was normal. (But I have not looked in every trannie under the sun either....)

Are you seeing something or just having a reference for regular checks?

There's always some oil (and particles) left behind when you change the oil.

So I wanted to drain the oil, run it thru a lab filter, reinstall the oil, drain again.


The idea being that the filtered oil would have little to none particles.

Then the remaining particles in the tranny would be diluted and disbursed, and I'd get more of them out with the 2nd draining.


Knowing the particle size, I'd know what size lab paper to get.

Getting the smallest lab paper (and most expensive) doesn't make much sense if the particles are much bigger.

And getting a paper with pores too big wouldn't work either.


So knowing the particle size would help me select what size filter paper.

Or if the particles are really small (smaller than the oil film) I really wouldn't have to bother with the filtering.............

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I think you may have brought a level of precision to a 3 speed box ....that might be better suited to something more sophisticated.

The Dexron should have that thing spotless after 1 change.

The particles that are small enough to float in the oil are munched by those massive gears .....

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Well that IS interesting. I guess I would get a pressure sprayer, put kero in it, and blast a coupla gallons into the top hole while the bottom plug is out! Then just take it to the local guys who has a used oil burner.....Then, if it is a non-synchro 1st gear unit, you ruin the whole treatment with a few times forgetting to not donwshift into 1st while moving......

There is very little brass from the synchro's in the fluid and it tends to stay trapped in the gunk caused by the iron fines attached to the magnet. If you are getting flecks of brass large enough to see in suspension when you hold the fluid up to the sunlight that is a bad sign in a manual transmission.
If you really want to separate small stuff out a centrifuge works wonders.

So far all the A-833OD's I've torn down have had particles in them closer to the grains of sand...I also have one that the previous owner over tightened the case bolts and busted some of the aluminum casing out as a large scab after the bolt bottomed out and kept going...they were at the bottom of the sump and about the size of your thumbnail....(the case is now a door stop).