Is the 722.6 transmission oil really eternal???

[A. Rosich]

The owner's manual on my S 500 L states that the 722.6 transmssion oil should NEVER be changed.

The local M.B. dealer here in Costa Rica says that they have found out that due to the extreme weather (very humid and rapid tropical temperature changes) and traffic conditions (short distances/continuous stops) here, the special transmission oil used on the 722.6 auto transmission should be changed every 60,000 kms.

They point out to a couple of W140s who had fatal transmission failures at about 90,000 and 100,000 kms. here. After a post morten inspection they found the oil to be defective.

Do you beleive this story?

Comments would be appreciated.