It was [USER=4874]@frank[/USER] that called it, the strap I mean. They shouldn't come apart unless it's a sh#te Clutch or you've been dropping it like a phat beat at a Skrillex concert. But yes, strap caused the damage to the seals.
I've never seen dirty gearbox oil, its just cogs in a box so the worst you would see is metal swarf in the oil. Engine oil goes black because its subjected to heat and the combustion chambers / cylinders.
You may find that the loose strap has done damage behind the flywheel, allowing it to get into the bell housing.
Chris.
