ATF Level Discrepancy: What would you make of this?
 

According to owner's manual, ATF level should be at full/maximum mark when transmission is at operating temperature; OR 10mm (about 1/2") below minimum mark if at shop (i.e. room) temperature. So I check my level when cold and it's where it's supposed to be. But then I check when hot and it's 1/4" ABOVE full mark. And yes, I give it several minutes to settle down and cycle through R, D, and N.

I might have thought that 1/4" is nothing to be concerned about, but several much more knowlegeable than I have encouraged me to remove the excess.

What gives? Which of the two readings is likely to be more reliable?

Best case scenario: Level at MAX mark when trans is at 80C.

Some of the guys are saying MB issued a bulletin suggesting 20C method is not accurate.

Unless you drive 20-30miles the fluid level should NEVER be at the full mark.

Overfilling causes "foaming" & foam doesn't lubricate that well.

So drain or suck enough out to be at MAX when hot, then check level when cold and use that new, lower level as a guide.

Steve

Trans fluid expands as it warms up. So when checked on level ground cold it should be between the add and full marks. If it reads full when first started, its overfilled.