So is the gear/final drive oil change every 24,000 miles and does it possibly require removal of the exhaust system?
Correct on the first part, 24k miles. The service manual says drop the exhaust manifold to access the drain plug, but a poster on this forum had a workaround. I copied it and pasted it below.
Photo shows drain and fill plugs. Neither is easy to access.
FORUM WORKAROUND, WITH MY NOTES:
GEAR OIL
Due at 24,000 miles. Order new gasket in advance.
MOTUL Gear 300 75W90. Need 250 ml. Install new gaskets since this is such a rare maintenance job (same gaskets as engine oil drain plug).
GASKET FOR GEAR OIL DRAIN PLUG: BMW # 07119963252
GASKET FOR GEAR OIL FILL PLUG: BMW # 07119963252 (SAME … ALSO, BOTH ARE THE SAME AS ENGINE OIL GASKET FOR DRAIN PLUG)
TORQUE filler and drain plugs: 28 Nm (20.5 ft. lbs.)
FROM THE FORUM: “II can save you a lot of time and aggravation. The manual says take off the right side panels, drop the radiator and disconnect the exhaust manifold. DON'T DO IT. Instead, disconnect the muffler from the frame, then disconnect the center stand. I didn't realize it until the end but the exhaust is held up by the center stand. Take the stand apart and the exhaust flops down far enough to give you access to the drain plug. Just put something over the expansion chamber so you won't get oil all over. Drain and fill with 250ml of 75w90. Easy peasy!”
FROM THE FORUM: “In order to drain the gear oil I tried the muffler and the center stand like someone said. It worked but is risky, you don’t have enough space to unscrew so you must put force to keep the exhaust down. Pain in the ass! And you risk breaking the manifold screws (you don’t want to do that). It’s better to remove the entire exhaust like BMW says.”
