Can use DAM2905 NEW green 16 teeth worm spindle - that the speedo cable drive attaches to. Sometimes a little tight in the 2A3624 housing but just rotate to loosen up.

It has 16 yellow and was used on the 3.2 final drives with 22G2022 drive spindle which had 5 teeth.

The DAM8074 worm used on the ERA Mini had 16 teeth but yellow in colour and used a 5 tooth drive but is very similar and same diameter 20.4mm.

BEWARE-There was also a different green (17) tooth drive DAM2904 which was fitted to the MG Metro with 3.4 diff and can be used in place of 22A1881 for all early minis.

Plastic worm gears used on production minis.

15 teeth TXD10004 black worm

16 teeth DAM2905 green worm

17 teeth 22A1881 clear/white worm

18 teeth TXD10006 grey worm special size