technical
Replacing a 300Tdi Salisbury axle with a Td5/Puma 110 rear axle
The Salisbury axle on a Defender 110 was used through the Series era until 2002. It has a reputation of being very strong, but also not very DIY friendly, as the pinion is part of the axle casing and the diff carrier removed by needing to spread the axle casing apart. So to replace the differential you would effectively need an entire new axle....