I would say this is about normal for a used diff, and you can't tell where the wear is, it won't all be crown wheel to pinion back lash even with the handbrake on. Is it particularly noisy? My two cents would be that playing with pinion backlash probably isn't a great idea unless you have some reason to think that preload is low, e.g. noise changing between drive and coast?  

Remember discovering this myself early in my ownership cycle . Back in those days my local BL dealer (jyst across the street) were able to help. But not on a Sunday afternoon .

My spare for the front is a nylon one, probably from about 10 years ago when I bought a pair but never only replaced the bad one, so hopefully still good.  The rear one definitely needed doing after I noticed some vibrations. I'll let you know how the kit installation goes.  

All useful bits of information, I agree the order of discovery is suboptimal. One more for you; most trunnion kits sold these days are barely fit for purpose if at all. I prefer the Witor/Superflex polybushes on the front at least. Not cheap but they fit properly and last very well. I believe they are also available for the rear, though I’ve not yet tried them. Bella needs a pair…. https://www.superflex.co.uk/proddetail.php?prod=SF375-1850KSS Might be available from elsewhere too.

Carney offended him. What a suck!

I have a lot of play on the diff input video here: This is with the handbrake on and so no output movement.  This diff has a castellated nut with split pin, so shims on the input.  Is there anything I can do or is it just on its way out?    

This was the response: My father was in the Western desert ( he was in operation Compass and in Tobruk during the second siege ) but he didn't get as far as Italy.  He was on battlefield ordnance-clearance but he didn't talk much about that - it included having to enter knocked-out tanks to dispose of unstable and unexploded ammo and you can guess what else might be in there.  His luck ran out in 1942 when some dodgy Italian shells he was dealing with exploded prematurely.  He spent a long time in hospital while they put him back together.   Stlll, he fared better than his elder brother who was lost on HMS Barham when it was torpedoed and blew up in 1941.   

Hi NickyT please keep rambling   Roger

Hi Nicky T, Thanks so much for sharing your story.  I truly appreciate learning and hearing historical stories told by those who have lived them. I also enjoyed being enlightened about actual changes made to the movie. I'll have to watch both again. I only wish the 35% of my "fellow " Americans who are ignorant and want to stay that way,  deny the past and seek to rewrite it.  The orange ape wants to remove long time historical texts from our educational syllabus.  He says SLAVERY was a good thing, it taught them so much about  ???????.  The Governors of Florida and Texas have removed textbooks from schools and libraries. The USA is becoming a very dark country. I thank our European Allies ! Steve

Today I discovered a few useful things, in a non-useful order. 1- the rear trunnion bush bolt is a pain to get out, and really need the driveshaft off the car if you don't have a really good clamp to press the bolt out. 2- front and rear trunnion bush kits are not the same. 3- the spare trunion bush I have in stock is a front one. Spitfire is now stranded on 3 wheels on the drive looking a bit like a dog about to mark it's territory!