Thread: Identifying series gearbox - no gearbox numbers present. Help!!!

I'm trying to identify a series gearbox I just removed. However there are not the expected numbers where they should be and some of the numbers are short and weird so hopefully there are some gearbox experts out there who can help.

The transfer case has the number 5 S 5 A 2 on the rhs (the second 5 is stamped upside down) and the casting on the transfer casing says "Marshall 539788" with "A1 XX".

The bell housing has 7421 stamped into it.

The LHS of the top cover has 2A stamped in it (is it that obvious - 2A maybe?).
At the front of the top cover where the casing meets the top cover there is a ZZ and a B and on the casing itself is a XX stamped.

It is on a series 3 with holden conversion but they have used the series 2 clutch setup to match the conversion kit which has a cast iron bell housing. The gearbox has been sprayed silver but under that is red oxide type paint and army green on both the gearbox and the other fittings. Is it possible it is a 2A army box? I'm imagining that it should bolt up to a series 3 bell housing as every other aspect of it's mounting works in a series 3. Seems smooth with no play and all the gears work nicely, so hopefully it is a good version of the box.

Any pearls of wisdom?

Number should be stamped on the RH side of the sloping bit near the top along the join with the transfer case. Your description does sound like an army overhauled box, but does not necessarily mean that it is.

Provided the bell housing is for the appropriate (four or six) engine, the Series 1/2/2a/3 boxes are bolt in swaps except for the clutch release setup which is different in the Series 3 (and a few very late Series 2). For the 2/2a/3 the boxes can be swapped just with changes to the piping, and the Series 1, 2/2a boxes just bolt in, but because the clutch release is mechanical, not hydraulic, it would be necessary to fit a Series 1/2/2a bell housing and clutch release or to convert the pedal to hydraulic operation.

John