Some 40+ years ago Geoff LLoyd and I each needed to get axle eyes shrunk and nipped out one lunch time to Almondsbury Forge, which was well known for such repairs. Here we met the boss who quickly let us know he was a coach smith NOT a blacksmith! He was in his seventies and knew all about tempering metal. He could do the job but needed a mandrel 10 thou undersize - his was mislaid. This was to anticipate the resultant hole being slightly barrel shaped. That afternoon Geoff machined up a mandrel, ground a flat on one side and stamped it "A7". We returned at the same time next day and watched as the axles were heated in the forge, dressed into shape and quenched in sperm whale oil. This was the key part. During the afternoon, Geoff had the axles up on a miller and took the eyes out to half an inch.
Thousands of miles later, and coping with hydraulic brakes, the eyes are still tight.
Ron

Location: South Gloucestershire

And just in case anyone intends handing the Solid Edge drawing to a repairer, the k.p eye is nominally 12.7, but the exact dimension is less.

I dont know what the recommended interference is. If too tight easy to damage the pin if driven in.

My father acquired our RP in 1940, when Southward was apparently still working in the Seven business. For reasons unexplained he told my father the RP was the best Seven....maybe it was a line he used to sweeten possible customers.

Wartime material shortages and demand, and postwar restrictions enabled Southward to prosper.
Postwar he ran a Merlin powered speedboat. I suppose after driving Sevens he was used to the noise!

Bob Culver

Location: Auckland

The kingpin should be a tight, hand push, fit in the axle, the cotter locks it in place. If you have to drive it in with a hammer it is too tight!

Location: Devon

Hi Tony

It is difficult now to know what the typical mileage of a Seven was in its day before the car was set aside. Most cars did low miles during the War. And it is difficult to know what the typical service history was. Based on a variety of 1950s cars, most seem to succumb in the 130,000-170,000 range, excluding smashes. My RP in constant use, 100,000 by 1957. At that mileage kp eyes had been done at least once and needed again. On light pre 1932 cars axles presumably lasted longer. But many of those cars with fabric bodies etc succumbed early (although the axles lived on!) On heavy Girling cars axle life shorter.
Some scrapped Sevens showed general wear indicative of formidable mileage but could just be due to servicing neglect.
The Austin agents were the main source of parts here and may not have touted oversize pins in the earlier years. Forging closed seems to have been the general remedy.I have also seen axles lined with bronze, a more dubious process. Very thin sleeves easy flowed and turned away another variant.
I suspect by the 1950s when the cars quickly disappeared most would have been treated at least once, at least here near Wellington where Southward reigned!
The front axle was presumably quenched originally from a high temp (below that acheived in welding and above that in conservative reshaping), leaving it somewhat brittle, then tempered (not necessarily quenched) at a faint red. Raising above the latter softens the steel somewhat.
As with spanners, thick non premium metal deflects less than springy thin so building up net beneficial.

Bob Culver

Location: Auckland