Hi,

I have a standard 1.2 ratio transfer box in my manual 300tdi Disco 1, and I have a replacement 1.4 ratio transfer box from a defender - as i have bigger tyres I want a better ratio for drivability.

I rang a garage today that specialises in gearboxes for a quote on labour to replace the clutch and swap the transfer boxes over - they seemed a little concerned that I was swapping the transfer box without doing the axles - Am I right in thinking that I can just have the transfer boxes swapped over? I was positive it was fine but now I'm doubting myself!

Thanks.
Foz

Personal opinion says just do it, all you're doing is lowering High ratio, gearing! Low ratio is the same in all the transfer boxes, I believe. However, lowering the gears at the axle _will_ affect the gearing of the low box too, 'cos the overall gear ratios are altered ...

Driveability on road will be improved with the transfer box change, driveability offroad will be improved with the axle ratios changed. You DO have to do BOTH axles the same ...

Paul D said:

Personal opinion says just do it, all you're doing is lowering High ratio, gearing! Low ratio is the same in all the transfer boxes, I believe. However, lowering the gears at the axle _will_ affect the gearing of the low box too, 'cos the overall gear ratios are altered ...

Driveability on road will be improved with the transfer box change, driveability offroad will be improved with the axle ratios changed. You DO have to do BOTH axles the same ...

Click to expand...

Thanks for the clarification, I thought that was the case.

It's fine off-road in low range for now, it's just a bugger to tow and to go up hills haha.

Foz

I did it on my Disco two years ago - one of the best mods I've done. I'm on 315/70/17 or 34.5" in real money.

If you are trying to work out where you are and want to be.

Try using this. it will give you an idea of what you will get.
http://www.ashcroft-transmissions.co.uk/calc/ratio_calc.html

Cheers