Thread: Land Rover Tool 600300 for Gearbox mainshaft nut.

I've only ever seen one of these and it had 4 prongs on it not the 8 that are on the nut.

Most people end up using a chisel or drift to undo and then do up this nut with the same but this stresses the mainshaft and the torque is unknown. It is possible to shear the mainshaft or crack it so that it shears later. Making the correct tool is the only answer as you need to tighten to 90-100ftlb (from memory - please check)

Some people have used a deep socket and carefully ground the 8 points into it, but I think I have come up with another easier option.

The OD of the nut is 41mm, and the drive dogs go to an ID of 34mm. This means you need something over 34mm inside to start with that is long enough to go over the mainshaft spigot, and has a nice 1/2" drive hole at the rear.

I have found a cheap starting point by picking up a 45mm concrete hole saw which has TC tips brazed into the end of it. As we can use an old one it should be quite cheap. Find the type with a threaded hole at the end rather than a mandrel.
This is a deep cup with a heavy wall thickness and a hollow end. I've also bought some 1/4" key steel which is air hardening and fits the nut slots perfectly. and an old 1/2" drive socket.

The idea is to use a torch to melt out the TCT inserts, then grind or hand saw & file out slots in the correct positions to take 20mm long pieces of key steel, then braze them in or you can use a gas torch. Then weld on the socket to the rear to give a 1/2" drive. As you are heating the keysteel it will end up harder than the base metal.

At a push you could just cut the slots and bend in the steel but it will not be as strong as the hardened keysteel.

Hi I made one of these 30 years ago to fit the castle nut ,, Just get a correct size socket and go to work with a good hacksaw or thin blade grinder,, Takes 1/2 hour or so just keep trying it ,, ,Unfortunately when I migrated to Aus I gave it away to a garage in Mid Wales,, Well known country Landrover repairer,, Cheers Hayden.
Better than $168.off the net