TVR differential question(s)

[94Griff500]

I've got a 36k miles mid '94 Chimera/Griffith GKN differential that feels to have too much "play" as measured by being able to rotate the driveshaft input flange from about 12 o'clock to 2pm with seemingly little / no movement at the axles. That seems to be an excessive amount of play / clearance assumably at the ring to pinion shaft contact point.

I also understand that the '95 serpentine engine & later cars switched to a BSR (?) differential, and that parts and service on the prior GNK differentials are expensive or unavailable?

Can any one shed light on their experience with servicing a GKN?
What about the input "play" described above: is that normal or excessive?
I've read somewhere that either of these differentials are very difficult to remove? Is the GNK worth a removal / takedown?
What is an acceptable amount of input flange rotational play? Where & how is that play adjusted?

As always: Thanks for any advice!

[sixor8]

I can't advise on maintenance but thought I could add that the rear diff used from late '96 (ish?) was the BTR. There are brackets available for one to be used instead of the GKN if you wish.

https://www.centraltvrparts.com/product/centre-dif...

Other suppliers are possible. Racetech seem to have mounting parts for both:

https://racetechdirect.co.uk/transmission/differen...

[PabloGee]

These are the name in diff rebuilds, they did my GKN, and it’s fine.
http://www.readmanracing.co.uk/

Two things to note:
Ask them about fitting the later back cover with the full and drain plugs on the side - it makes oil changes a million times easier.
Get the right polybushes when refitting - the fronts are different from the later BTR diff :

https://motaclan.com/product/bush-gkn-diff-early-g...

And the rear:

https://powerflexstore.co.uk/tvr/griffith-chimaera...