Series 3 gearbox with 3031 stamped on case?

[pallison]

I have dragged an series 3 gearbox out from the dark depths of the barn, to use on a tdi conversion, I have dismantled it, to find water had been in it, so bearings need replacing, gears I hope will clean up, but, there are no suffix serial numbers on the casings, all casings ( cog box, transfer and 4 wd selector) have  3031 stamped? however the transfer case is stamped 3031xx. have attached photo of the cogbox/trans marks. as you can see there is no evidence of marks being ground off and then re-stamped.

many thanks in advance

[secondjeremy]

In the interests of being helpful Land Rover decided that it would be best not to number S3 main gearboxes and to stamp the number on the top of the transfer box - where you show your number.

As far as i know S3 numbers run like the vehicle numbers and begin 901 and run on to 902 when the 901's were exhausted.  The important bit was the suffix letter as there are 4 types of S3 box.  The original is suffix A - which suffered from a weak reverse.  This was improved for suffix B, Suffix C introduced chemically machined teeth and suffix D had coffin-shaped engagement teeth.  there's a bit more to it than this - all of which is shown in the parts manual.

 

So apart from minor casting differences in the casing you can only tell them apaprt when you've dismantled the thing.  I took one apart which from the transfer case seemed to be an 'A' but inside it was definitely a 'C'.  What I did notice was the letter 'C' firmly stamped on the input shaft - under the seal housing.  I don't know if this was co-incidence or a definitive marker of the type.

Rover recon boxes usually have a plate screwed to the bellhousing stating what it is and the part no.  (recon parts have their own number).  Boxes supplied under warranty (ie when the customer expects a new box rather than a repaired one)  may only have the suffix number stamped (I found one in a 2a with just a letter stamped. )  the idea was that the installer would stamp the original number on the box when he fitted it.  The 3031 looks like a smaller font than Rover used so may not be a Rover stamping.