M46 & M47 Transmission Oil

From the factory, automatic transmission fluid is the specified fluid for both the M46 and M47 transmissions found in the 200/700/900 models. Over the years as synchronizer rings wear and tolerances increase, we have found that changing the transmission fluid to synthetic 10W30 motor oil makes a noticeable increase in smoothness and gear engagement. We have even noticed ‘weak’ overdrive engagement has become firmer with the new fluid. Using your clutch when shifting into overdrive can also help to reduce wear on the overdrive. Although this change in fluid does make for improvement in transmission operation it does not repair damage. As always be sure to use the proper amount of fluid to achieve the correct fill level.