Note from Randakk: This information applies to GL1000, GL1100, GL1200 and GL1500 models. It is likely applicable to any motorcycle equipped with a drive shaft and hypoid final drive gears that run in a bath of heavy gear oil.
It’s a common complaint and fact: early ‘Wings are prone to nuisance seal leaks in the final drive units (especially GL1000s).
At first, this is usually just an annoyance and may keep your wheel, tire and garage floor messy. However, as the leak worsens, it can becomes a serious safety concern. I’ve actually seen enough final drive gear oil escape that it got onto the tire tread and rear brake pads. That’s an obvious safety issue that can’t be ignored!