Oil Pump Modification- what is it ?

Hello, some advice please.
We are purchasing a fresh Discovery soon and have heard there is a modification to the oil pump that is worth doing. Not sure what is involved but I gather it's something to do with locktiting a bolt so it can't drop off thus causing loss of oil pressure.
A garage I spoke to recently said they do it to all their vehicles but I haven't heard anything about it and was wondering if it was just sales talk ! I believe it would cost about £250 to carry out? Is it common to all models ? All info greatly appreciated.

Apparently they were a large batch of Td5 that were let loose with out locktight on the bolt that holds the sprocket on the oil pump.This is chain driven and over time can come loose and eventually drop off resulting in one wrecked engine!!!
£250 sounds well expensive for just taking the sump off, unscrewing a bolt,locktighting & putting back.

Jason

But it's cheaper than a new engine...

JimAttrill said:

But it's cheaper than a new engine...

Click to expand...

Go's with out saying!

Many thanks