Which Diff?

[Colingo]

I've acquired an automatic 230 and I've spoken to a few people and had two different answers as regards the diff ratio : 3.75 and 4.08. Having consulted a '64 parts book for the 230 I've found that the 4.08 was available "on special request" whilst the 3.75 was standard. I don't know which is on my car. I've thought about recording revs and speed to work it out, but this assumes quite high accuracy in the instruments. I haven't got underneath the car yet - anyone any ideas how to identify?

[DaveB]

The ratio is stamped into a machined flat on the diff housing (lower left rearward-facing).
It seems 3.75 was standard in Europe and 4.08 in the US or for 5-speed cars.

[Colingo]

Thanks DaveB

Just the info I needed. Sounds more like I'll have the 3.75 although I'm hoping for 4.08 for my conversion.

[WRe]

Hi,
some more info, ratio right in the dark.
...WRe

[Colingo]

Hi WRe

I can't make any of those numbers tally. In my book I have:
113 350 02 00 Rear axle with thrust arms, ratio 3.75
113 350 04 00 Rear axle with thrust arms, ratio 4.08
also
113 350 01 39 Drive pinion with ring gear, ratio 3.75
111 350 07 39 Drive pinion with ring gear, ratio 4.08
The number from your picture looks like ?21062. Am I missing something?

Colingo

[WRe]

Hi,
the number on the left is not a part numer (113 ...) but the number of the rear axle as mentioned on the data card.
The ratio is on the right side, admittedly, the number is difficult to recognize, but you can guess the 3.92.
Here some more photos.
...WRe

[Colingo]

Thanks Wre

That makes sense now.