BTR filler plug size

[TVR Beaver]

I wonder if anyone knows the size (A/F) of the filler plug on the BTR diff??
I want to top mine up as I get the odd drip before going to LeMans but I can't remember the size spanner I used last time I changed the oil?
I know I had to bring a nice thin one home from work as non of mine would fit it...
Seen a post on here that says its 27mm... but thought it was bigger than that??,, or is it just me thinking things are bigger than they actualy are ( something my wife says im guilty of for some strange reason )
your help would be appreciated.. save me only having to jack the car up once... getting lazzzzy in my old age .. cheers !

[EGB]

i think 30mm will do. But 29mm is best.

[TVR Beaver]

Is it 29?.... I had something like 32 in mind?

[Loubaruch]

Are you sure your filler plug has a large nut, my 1996 500 has a square drive socket about 13mm ?

A pig of a job to access, a nut would be much easier to undo! Perhaps they changed them.

[Hedgehopper]

My '97 Griff needs a 1 1/8" slim open ended spanner. Guess this would be much the same as 29mm.

[TVR Beaver]

Cheers guy's... must be a 29mm I used before then.. unless I found a 1 1/8 here at work.. will now go have a look...

Thanks again!!

[TVR Beaver]

Loubaruch said:

Are you sure your filler plug has a large nut, my 1996 500 has a square drive socket about 13mm ?

A pig of a job to access, a nut would be much easier to undo! Perhaps they changed them.

96 are on the GKN diff.... and yes, it is a pig of a job to get to

[Loubaruch]

TVR Beaver said:

96 are on the GKN diff.... and yes, it is a pig of a job to get to

I realised after posting that it could be a different diff, but it was before my morning coffee so still snoozing!