Hopefully not stupid questions about Jimny Transfer cases.

Greetings all

a bit of background, I have built this contraption. WTF has this got to do with Jimnys? I here you ask, well read on. 


I have used a narrowed Jimny rear axle (I narrowed it myself)


The aim was to make something really really low geared with a 'strong' rear axle. 'Strong' being relative. It has an engine that barely produced double digits BHP. I used two Austin gearboxes (to go with the front half), but having built it, I am disapointed, as it is not slow enough!.

The main problem is that the Jimny axle as its designed for a transfer box, so the ratios are quite high (current one is 3.9:1) vs Austin 7. I should have used something like a Austin A30 (5.125:1 same as the Austin7). but those axles are very weak. All wheels are similar rolling diameter. And yes, I know I can fit the 4.3:1 diff off a later Jimny, I have one, it will basically make cock all difference at 1000RPM. I need some significant further reduction

So, as I have a Jimny front propshaft (lengthened) driving a narrowed Jimny rear axle, it struck me that a Jimny transfer box would halve my ratio. and I don't have to dick about too much with different UJ's etc. I already have spares having made a longer one out of 2. 

Can anyone answer me 2 questions which would help in my head scratching.
1. Is there a 'centre diff' on a Jimny? Or is the input shaft simply connected to the output? I would only want to use the input and output to the rear. nor the front output.
2. What is the offset from input to output centrelines please? can anyone measure for me?. I might end up with some fierce angles on the shaft. 

Many thanks

Welcome to the forum. I don't have one to measure just now but there is no centre diff and with a factory ones low range is 2.6 on the automatic gearbox version alternatively it's possible to buy internals that take it down to 6 or 6.5 among others if you want slow slow.

Ok, so the transfer case does as I expected.
Am I correct in the research, normal one is 2:1 in low. Auto one 2.6:1 in low?.

My pre war engine does not rev like modern ones. Seems to pull well enough at around 1100rpm, and the sums say I'm at less than 1mph. (1000rpm equates to 0.62mph).

Halving this, (or more) would get it somewhere I want it I'm sure. Its just about the offset now. I don't think I'd need to go 6:1, besides, I'm pretty sure Id not like to spend that sort of money on what is basically a toy.

Can anyone help with offset? I can scale from photos, but it would be good to have the proper dim to see if it will work. I have no rear suspension so I can go pretty severe in terms of angles, but I just want to see if it will work before going the buying one and see route, and then it doesnt.  

I have the sj transfer and by eye it's around 200mm sideways offset 
And around 100mm lower offset rear output 
Should imagine standard Jimny transfer is very close on dimensions