Tranny Fluid: ATF or Gear Oil?

[318idol]

This may be a dumb question, but there are mixed messages in Bentley manuals and my owners manual regarding manual transmission fluid:

The Bentley e30 manual (which doesn't cover the M42 318 cars) says manual trannys use a SAE 80 Gear Oil.  The Bentley e36 manual says that the e36 318 demands Dexron II ATF.  My 318 owners manual says use SAE 80 gear oil.

So, which it is?  Are they the same stuff?  Did BMW change its mind?  All I know is that gear oil is completely different than ATF, one thick and tacky, the other to thin and runny.  Besides, putting ATF into a manual transmission is counter intuitive.  

Gary

[bar73k]

if your gearbox uses ATF then it will have an orange sticker on it near the filller hole saying ATF.

another way of telling is if the filler plug and drain plug need an allankey to be removed then the gearbox uses manual gearbox oil.

If the filler plug and the drain plug stick out and require a socket like eg. 19mm then the gearbox runs on ATF.

[fabe]

I was once asked this question by an E36 owner and I was at a lost. He did mention there's a sticker on the manual gearbox displaying ATF oil.

[b318isp]

BMW recommend ATF (from TIS CD). If you find it hard to get 1st when it is cold, then this is a good route to go.

[D. Clay]

My only complaint on ATF is that it seems to make the transmission noisier. Especially idling in neutral with the clutch out - seems like you can hear the main shaft front bearing rattling.