This long-overdue repair to the steering box in the Red Rocket was made a lot easier by the removal of the engine. I'd noticed that the steering box was leaking when I first inspected the car, and it's been leaking ever since. I suspect it's been leaking for a long time — there was a minor rebuild kit in the box of spares that came with the car, but removing the box with the engine in the car is a tricky job, one that the last two owners never tackled.
The Corvette uses recirculating ball steering, a design that was introduced by Cadillac way back in 1940. It's a bulletproof design, but eventually wear on the shaft and bushings will necessitate a rebuild.
Removing the box should have been simple. Disconnect the steering column at the flex-joint, undo the nut that connects the pitman arm to the relay rod and remove the 3 bolts that hold the steering box to the frame. That all went smoothly, but there was no way the pitman arm was coming off the relay rod ball stud — it was welded on. I tried a pickle fork and a lot of 'persuading', but it wouldn't budge. I was able to dismantle the relay rod and remove the steering box with the ball stud still attached to the pitman arm. The relay rod itself was slightly worn, and the rubber seal was a mangled greasy mess, so it was overdue for a rebuild too.
The steering box was sent out for reconditioning. It got new bearings and seals, and the shaft was worn so it was machined and sleeved. Everything got a coat of black engine enamel before being reinstalled (the yellow paint markings in the pictures below are not factory original, they were added by a previous owner). The relay rod received a rebuild kit which included new cups, springs and seal.
The final result is a huge improvement, the steering feels tight, and there's no more leak. Note that Corvette steering boxes use chassis grease rather than gear oil. Apparently this is because the steering box sits so close to the exhaust, gear oil would thin out when hot and run out through the seals. If you've got a leaking Corvette steering box, check that it's using the correct lubricant.