Lt230 serial number

Hi all
Any idea how to work out the year / ratio from the serial number as it does not seem to follow the usual list. Was from a disco with interlock
Ta

Someone posted the ref numbers on here somewhere recently.

LT 230 Ratios

12D = 1.667
13D = 1.410
14D = 1.003
15D = 1.192
20D = 1.667
21D = 1.667
22D = 1.410
25D = 1.410
26D = 1.003
27D = 1.192
28D = 1.222
29D = 1.192
32D = 1.222
34A = 1.410
36D = 1.211
37D = 1.211
38D = 1.211
40D = 1.211
41D= 1.211
43D = 1.410
47D = 1.667
57D = 1.410
59D = 1.211
61D = 1.211
62D = 1.211
68D = 1.211
69D = 1.211
70D = 1.211
80D = 1.211
81D = 1.211

Yours appears to be missing the first number number.

From Ashcrofts website.
How can I tell the ratio of my transfer case when its out of the vehicle ?

Pls follow the steps below:

Put the transfer box in difflock
Put the transfer box in high range
Put a piece of cardboard in the input gear hole
Put a marker in the 12 oclock position on one of the output flanges
Count how many times you need to turn the output flange to make the input gear turn once.
Result :-

Just over 1.5 times = 1.6 ratioJust under 1.5times = 1.410 ratioJust under 1.25 times = 1.2 ratioApprox 1 = 1.003 ratio

At that age the numbers mean not much, I am afraid.

Follow the mechanical method above to confirm.

J