ADO16 diff ratio

[Andrew1967]

Just taking a rubber coupling diff out of an unmolested ADO16 gearbox to use in HOY (as the 333 box has a H/S diff in it which is not correct for a 65).

Noticed it has a 17/64 CWP which is 3.765:1. I thought that was a Mini ratio and ADO16 was 17/62 or 3.647:1

Can anyone confirm ?

[Beatie]

17/62 in the box I have Andy (71-MG)
Hope you are all well
Cheers
Jeremy

[bwaminispeed]

Just checked mine, 15/62 which is 4.31........

I think this was MKI 1100 ratio.....

[Costafortune]

The 1100 is 4.13:1 and the 1300 was 3.65:1, shared with the early 69-71 1275GT.

1100's were very undergeared so it's possible a previous owner fitted an 850 Mini diff. Has the engine been in a Mini at some point?

[bwaminispeed]

OOPs, yeah, inverted the last two digits.......

I think the Austin America version of the 1300 was 3.44 (better suited to North American highways)........but, I may be mistaken....

[Andrew1967]

Thanks for the replies thus far ...

I've no idea what the gearbox was fitted to, I rescued it from my usual parts source, thinking it was a MK1 Mini remote box, without really looking too hard .. when I got it home I noted the ADO16 remote mounting points

On the upside it was cheap and has a very good B type 1st gear and also the diff is going to be used in HOY, with a CWP change. Casing is also very good so if anybody needs one ....

[Spider]

Here we got 3.44, 3.65, 3.76 (in the later models), 4.133 and 4.26.

The early Autos had (a very rare) 3.48 but most had 3.27 in common with the Mini.

[whistler]

Early standard ADO16 1100 engines had 4.1:1 diff which was great for us poor ralliers. We just transplanted the whole engine/gearbox into our minis and had added acceleration as the mini had 10" wheels not 12" as on the ADO16.

[Supersonic]

Throughout its production the 1098cc ADO16 gearbox retained a 4.13:1 ratio final drive. The very early 1275cc engines suffixed by engine number 12G had a 3.44:1 final dive ratio which was latter changed to 3.65:1 ratio for all models. Like Chris said the 1275cc automatics had a final drive ratio of 3.27:1 and and early 1098cc automatics had a 3.48 final drive. It should be noted that these auto crown wheels and pinions will not fit into a manual gearbox due to an increase in the diameter of the crownwheel. I recall the very early 848cc Wolseley Hornet I owned had a 3.76:1 final drive from the factory.

Alan

[goff]

Andrew during the 60s and 70s lots of Morris and Austin 1100 engines/gearboxes were fitted to minis , straight swop , you got a remote also and more power for little outlay ! a fiver for a scrap 1100 was all you would pay and it was usual to swap the 4.1 final drive for the minis 3.7 final drive from the engine and gearbox you had just lifted out , hope this helps

[Andrew1967]

All interesting comments here, thanks everyone

Goff, I reckon you have hit the nail on the head on this one.

[Costafortune]

Has the engine been in a Mini at some point?

[spoon.450]

Every day's a School day...…...if only...
Great info BTW chaps