Does anyone have knowledge or experience of stub axle failures on these cars? The 2.5/3.5 are considerably heftier than the 1.5 but they all have an ultimate life, and like human life we don’t know when that is.
I am an MG tragic too, and they have a history of fatigue failures starting many, many decades ago. It is a major safety failure, as you lose the wheel and drum assembly and of course the brakes. I have direct experience of this failure from back in the late fifties as a very young teenager. I had a Christmas holiday job as a helper (under age?) to an ice cream delivery supplier, and on our way back to the depot, I felt my passenger side drop a bit then noticed a wheel slowly overtaking us along the footpath. We were lucky in that the road was flat and straight and we were travelling at a gentle 40 kph or so. As a matter of detail, ‘escaped’ wheels usually go faster, as when the weight comes off, the rolling radius reverts to full size, so the speed increases because the r.p.m. remains the same.
But, traditionally, MG drivers often pressed their cars into severe competition, increasing the stresses dramatically. At least one supplier is making new ones for the early models, which would seem a good investment for the next 80 years of the car’s life. An alternative is a modification where they bore the centre of the knuckle out and shrink-fit a new machined stepped stub in place from the back. Similar, in principle to the later Jag i.f.s. stub axles. I can’t see that there is enough ‘meat’ in the Mk IV knuckle to do this.
I am considering getting some crack testing done (sometime), but are there new knuckles available?