Owners of pre 1980’s cars will be used to sliding spline joints that allow propshaft and driveshafts to alter in length as the rear axle goes up and down. They are terrible things. The steel against steel movement ensures rapid wear, and they don’t work very well under torque (not ideal for a drivetrain part).
It seems the guys at Aston Martin put some thought into this problem. You can see the thinking: ” Why don’t we put 8 rows of roller bearings inside an extremely complicated housing machined and then ground to an exacting tolerance? I mean it’s not as if the rear axle is complicated enough already.”
It’s a wonderful solution. Metal rolls against metal so wear will be minimal, they’ll work under torque, and should last for ever. Must have cost a fortune to manufacture, but the Aston solution is by far the most effective I’ve seen prior to the introduction of plunging CV joints.
I’ve been replacing the rubber boots – they’ll slide over the bearing carrier with the aid of a cone made from an old oil can (much the same approach as you’d use for replacing CV joint boots).