Mercedes recommends Type A Suffix A ATF for the 201 and 124 manuals. Unfortunately this is a long obsolete ATF specification. It had a small quantity of whale oil added to prevent wet clutch chatter and became illegal in the US circa 1970 when whale products were outlawed.

The old clutch type LSD "friction modifier" additive was also whale oil based, and industry went on to develop a synthetic additive to replace the whale oil, which is what is used today as a LSD and ATF friction modifier to prevent clutch chatter.

The current evolution of the old Type A Suffix A ATF spec is Dexron III.

Mercedes also lists SAE 20 non-detergent motor oil as an alternative, but I would not use this unless you are in the tropics.

Redline MTL is a specially formulated synthetic oil designed for manual transmission applications that specifiy ATF. It is rated 70W-75 GL-4. A 70w-75 gear oil is about the same absolute viscosity range as a 10W-20 motor oil.

MTL is what I use.

Larry's use of 10W-30 is probably okay, too. I always thought it best to use specially formulated gear oils in manual transmissions, but last year when I helped a friend change the transaxle oil in his mid-nineties Prelude, I was surprised to find that Honda's recommended oil was 10W-30 motor oil, so that's what we used.

The recommendation for my MR2 transaxle is 75W-90 GL-4 and I use Redline MT 90, which is basically the same as MTL, except for the wider viscosity range.

Duke