After several months now without any major problem, I was returning from a trip down to Devon along the A303 when there was a clunk the engine stalled and the car coasted to a halt. Once safely on the grass verge I depressed the clutch, restarted the engine, release the clutch gently and the engine begins to stall. So, off down the road I march to locate a phone box and call the AA to drag me home.
Initial suspicions were the gearbox had jammed since the car had coasted to a halt my impression was that this would indicate that the diff was still turning. So I duly ordered a fresh gearbox from Rimmer Bros. Once the box had arrived I set to work under the car to prepare it ready to swap the box over. I was never expecting to be able to turn the prop but as I'm dropping it out I notice that I can't turn the prop at the rear axle end, whilst the gearbox end turns freely. With the prop out I power up the engine, select a gear and lo and behold the gearbox is working fine. Rimmer Bros. have graciouslly taken the gearbox back, but it leaves me with the problem of a dodgy differential.
The first job was to turn the car around in the garage so that I could get at the back axle. Off come the road wheels, then the brake drums, brake shoes and handbrake cables are detached after that. I try to remove the rear portion of the exhausts but the joins are pretty solid the plan therefore changes to dropping the rear axle onto the loosen exhausts and relying on the fact that they are flexing on the rubber mounting forward of the front silencer. The pipe from the footbrake was removed and finally the bolts started to come out of the support arms to allow it to be dropped and slid out beneath the fuel tank.
For some reason I'd expected the differential to be dry, I think my theory being that it failed because the oil had leaked out. What really happened was that I spent a long time cleaning up a litre of oil that spilt across the floor. With the back cover off however it was clear to see that the drive pinion had sheared off as had the two idler gears on the cage. The half shafts are probably intact, but the force of shearing the idler gears has proably wedged them onto their gears since even using the Hayne's method of running some M10 bolts through the back against the bearing plate the bearing plate was distorting before the shafts would shift.