What's this brass thing on a syncro trans?

[newerwesty1987]

What is that?

[danfromsyr]

not stock.

might be a capped off fitting to be used in (future) plans of a oil cooling/circulatory system.

[newerwesty1987]

Ok. Maybe could have been for a temp sensor?

Is there a hole of some kind there anyway?

[MarkWard]

It looks like an AN pipe adapter with a cap on it. The case was machined for it. It’s not at the full level or the drain level. Syncro transmissions have more than a few innovative add ons.
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[syncrodoka]

You gonna have to tell us. Talk to the builder, previous owner and/or unbolt the cap and look.

[Sodo]

That's a suction fitting for a "future" gear oil cooling and filtration system.
Added by a rebuilder by customer request.
Current thought is that adding a bigger engine to a 90hp transaxle with many high-miles parts,,,, suggests that increasing transaxle lubrication is prudent.

It allows oil suction without using the transaxle's drain hole.
Many vans have an exhaust crossover pipe that passes close-by the OEM drain hole, causing 'cramped conditions' for the oil suction fitting, a real benefit.

My current thought is that sucking the oil from the bottom (the drain outlet) ensures that you get ALL of the heavy metal contamination out of the transaxle and push them thru the filter, at FIRST opportunity. But the exhaust pipe proximity is a bit of a hassle.

The concern, is that if the oiling system were to pump all the oil out onto the ground (a failure of course), the pump can't suck the last bit of oil and the R&P will dip down into some oil for awhile.

This has some validity, but it's fairly easy to install a pressure sensor/alarm that would alert you if the pump ever is running and there is no oil pressure. Exactly like on your engine oil light.
Which works well on the engine.
IMHO this would be best because you can suck any heavy metal particles out of the trans ASAP (before they circulate the trans causing wear) and you have an alert system.

I'm not using an alert system (yet?), I'm relying upon proper oil line routing and luck too.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[newerwesty1987]

Thanks for the explanation.

As far as sucking oil from the lowest point goes, I see where you are coming from but I think there's so much turmoil in the case at any decent speed that it wouldn't matter where you are really sucking oil from.

I'll just keep it capped. I don't personally feel like adding more complexities to the syncro is a good thing in general. I fully understand the logic but there are diminishing returns to take into account, like the results of blowing a line in the example above, and so on. Rancho advised not adding tons of power (Sub 2.2 is as far as I'm going) driving like a sane person and keeping it filled with 85-110 LAT oil so that's what I'm going to do and hope for the best.

[Sodo]