Front-drive transaxles have had a common oil supply with the final drive (differential) for many years. There have been exceptions, primarily older Chrysler front-drive automatics, with seperate drain and fill plugs for the final drive. Though seperate, both transmission and final drive use Dexron II transmission fluid.

However, if you have a 4wd system, the transfer case and rear-axle differential housing have their own oil check and fill plugs. These gearboxes typically use SAE 80-90 gear oil type GL-5, though in some cases they need a special factory oil.

In hard use, change the oil annually (siphon the oil from a differential housing without a drain plug). In normal city/suburban driving, you should change the oil every two years. In each case, check the level at the fill plug during every engine oil change.