What is turning in the Transmission at idle, clutch out?

[DOCTORBILL]

While the engine idles (like warming up in winter), is anything turning in the
transmission (clutch out)?

If so, does that turning - whatever - cause the fluid to slop around inside the
transmission housing?

Does the fluid get around to all the parts at first startup before driving?

DoctorBill

[Hugemoth]

Interesting thought DrBill. Judging by the location of the fill hole there may not be oil circulating around.

Q

[Woodie83]

Most of the transmission is turning, none of the final drive. All of the transmission is getting lubrication as it's so close coupled the parts which aren't turning are directly next to parts that are. The countershaft, differential, and final drive gears don't move until the car moves, but they share the same lube so some sloshing and the warming up process has begun.

[redpepe]

not sure how the 'fill hole' gives an indication?

if the clutch is actually 'out', what power input warrants the ' Most of the transmission is turning'? the clutch is usually 'in' / engaged while idling i'd imagine .... and turning the 'disengaged' gear sets.

as i understand it, trans oil is relatively thick and sticky so that all parts remain coated for a long time. the actual film that 'does the job' is molecules thick and is specially formulated to resist the high contact pressures between mating parts. for instance, machine cutting oil often has a high sulphur content to aid the slippage of the areas and chips around the contact patch between tool and part .... no oil actually reaches the cutting edge .... whereas trans oil should remain between the sliding gear surfaces. the remaining volume of oil is there to maintain suitable temperatures and to adequately circulate within a given system.

drbill's question seems to be prompted by wonder whether cold weather inhibits oil's ability to reach the contacting surfaces .... from its iced over pool in the bottom of the case .... and whether there is slinging of the reluctant chunks while it's warming up. idling, the contact pressures would come from internal and 'preloads' as opposed to driving loads and my guess is that warm oil will do a more consistent job but the idle requirements are probably met even by cold oil.