blackwolf wrote:

Kevzeboy wrote:

... Ashcroft website say there can be a friction welding issue with the type of diff? ...

Crossed wires here, I think. There is a welding issue with TDCi front axles, well documented here on the forum, but this has nothing to do with the rear diff. There are no welded parts in the rear diff, and I cannot find any mention of any issue regarding the rear diff on the website.

Kevzeboy wrote:

... I have never rebuilt a diff, but all I have read seems straight forward for a reasonable home mechanic? Is this the case? (They are the short rover diff on the 110’s. Same as the P38, I have been told?) ...

The rear diff in a 110 is (or at least should be) a four-gear P38 "short nose" diff. It is a very rudimentary diff and not complex, but the short length of the pinion shaft can result in (relatively) rapid pinion bearing wear.

Adjusting the backlash in these diffs (and the Rover type diffs as found inter alia in the front axle) is very simple and requires little skill, however you will either need to use guesswork (aka "common sense") or obtain a dial gauge with suitable mount, and some means of measuring the diff carrier bearing preload.

If you need to replace the pinion bearings the job becomes more complicated and the special tools required increase since you will ideally need to measure the pinion "height" (i.e., how far the pinion protrudes into the pinion housing), which is adjusted by selective shimming, and the pinion bearing preload, also adjusted by selective shimming. There is nothing particularly difficult about this but it does require some precision measuring instruments and a certain understanding of the principles involved.

On a vehicle which has seen as little use as yours it is unlikely that there is any problem with the pinion bearings and it is probable that all you would need to do is to adjust the backlash between the pinion and crownwheel.