I don't know how many of these early diffs you have actually worked with, but back in the 1980's when I got into Land Rovers (Here in the western USA) , I was impressed with the machining, materials and finish quality of the 1950's Land Rovers components. As I got into serious off roading / rock crawling, and the "Coiler takeover" happened in the Land Rover community, I dabbled in some of the later stuff, but I came back around to my 1950's Land Rovers. Living in a part of the world that doesn't have the horrible corrosion that you deal with, I have the joy of owning / working on original, non rusted series I's, a number of which are really used ! I have been thrust bolting diffs for 30 years, and I ALWAYS use the early (1958-older) diff castings as they are not SGI like the later ones. They are steel castings and they weld beautifully. Due to lack of available lockers in the early years, I actually machined and re-drilled a locker for a Dana 44 to fit the Rover crown wheel. After 24 spline lockers became available in the 1990's I tried the 24 spline shafts for a number of years, but tired of breaking even the 4340 ones. I built hybrid axles of various types, but finally got back to playing with the old Rover diffs, leveraging my old know how with them. Nowadays I run original series I diff castings with my own Stellite faced thrust pad setup, Ashcroft 3.50 (the only ratio I think will stand up to my abuse) and Ashcroft air lockers that I modified by annealing the side gears, machining for 1.400" 32 spline, then heat treating to my specs. I bored the bearing journals to just pass the big 32 spline shafts that I machined and had heat treated to my specs as well. The rears are still semi-float (Yes, I'm a series I purist on that detail !!) and are totally stock appearing from outside. I set them up with twin big tapered roller bearings each side that fit the original series I bearing housings perfectly, the the bearings are bigger than a Defender full floating hub bearing. The front is where the really cool stuff is, as the MUCH larger series swivel balls come into play..... You see, the series balls are super thick, yet made of EN16T, the same as coilers. I machine a very large amount from inside them, press in 4130 chromoly bearing adapter rings, and run a narrower swivel pin bearing pushed further out. This allows me to use a huge CV joint (beefier than 101 FC, I used to break those !!) The front inner shafts are my own custom 1.400" 32 spline units. I sleeved both front and rear axle casings to prevent bending on the big rock stair cases that I bounce up and down, shaved the drain plugs off the bottom, and filled the bottom section with 3/8" thick steel plate. The ability to run these huge CV joints, combined with the better metallurgy in the diff castings themselves, combined with MUCH bigger swivel pins / bearings is why I feel the series axle assemblies are a most highly under-rated platform. Thanks for the nice videos !
I don't know how many of these early diffs you have actually worked with, but back in the 1980's when I got into Land Rovers (Here in the western USA) , I was impressed with the machining, materials and finish quality of the 1950's Land Rovers components. As I got into serious off roading / rock crawling, and the "Coiler takeover" happened in the Land Rover community, I dabbled in some of the later stuff, but I came back around to my 1950's Land Rovers. Living in a part of the world that doesn't have the horrible corrosion that you deal with, I have the joy of owning / working on original, non rusted series I's, a number of which are really used ! I have been thrust bolting diffs for 30 years, and I ALWAYS use the early (1958-older) diff castings as they are not SGI like the later ones. They are steel castings and they weld beautifully. Due to lack of available lockers in the early years, I actually machined and re-drilled a locker for a Dana 44 to fit the Rover crown wheel.
After 24 spline lockers became available in the 1990's I tried the 24 spline shafts for a number of years, but tired of breaking even the 4340 ones. I built hybrid axles of various types, but finally got back to playing with the old Rover diffs, leveraging my old know how with them. Nowadays I run original series I diff castings with my own Stellite faced thrust pad setup, Ashcroft 3.50 (the only ratio I think will stand up to my abuse) and Ashcroft air lockers that I modified by annealing the side gears, machining for 1.400" 32 spline, then heat treating to my specs. I bored the bearing journals to just pass the big 32 spline shafts that I machined and had heat treated to my specs as well. The rears are still semi-float (Yes, I'm a series I purist on that detail !!) and are totally stock appearing from outside. I set them up with twin big tapered roller bearings each side that fit the original series I bearing housings perfectly, the the bearings are bigger than a Defender full floating hub bearing.
The front is where the really cool stuff is, as the MUCH larger series swivel balls come into play..... You see, the series balls are super thick, yet made of EN16T, the same as coilers. I machine a very large amount from inside them, press in 4130 chromoly bearing adapter rings, and run a narrower swivel pin bearing pushed further out. This allows me to use a huge CV joint (beefier than 101 FC, I used to break those !!) The front inner shafts are my own custom 1.400" 32 spline units. I sleeved both front and rear axle casings to prevent bending on the big rock stair cases that I bounce up and down, shaved the drain plugs off the bottom, and filled the bottom section with 3/8" thick steel plate.
The ability to run these huge CV joints, combined with the better metallurgy in the diff castings themselves, combined with MUCH bigger swivel pins / bearings is why I feel the series axle assemblies are a most highly under-rated platform. Thanks for the nice videos !