Sixto,

Yours is the better advice. Quoting the Owner's Manual for my '86 300E:

"If the transmission fluid cools down to 20-30 deg. C (68-86 deg F), which is the normal shop temperature range, then the maximum fluid level will be approximately 10 mm (0.4") below the minimum mark on the dipstick"

and

"The fluid level must not exceed the dipstick maximum mark with the fluid at operating temperature"

Thanks for the correction. I should follow my own advice about checking the manual more often.

I've edited my post to reflect the changes suggested by you and blackmercedes.

Gary