I was looking at the drivers window on my brothers' 1996 Disco and will probably have to replace the regulator. When all was disconnected I noticed that the window becomes very stiff when pushed more than half way down. I can't see any reason for this nor can I see any method of adjusting the...

I use U Pol satin black aerosol on lots of items to refresh the colour and it lasts for ages, rubber hoses,all sorts of trim, door mirrors etc. I clean the surface well and spray light coats. It's cheap, worth a try.

Perhaps too simple, did the garage use the correct grade oil for the gearbox? I would also replace the filter again in case of a faulty unit.