37" Creepy Crawlers - whats the best transfer box ratio??

[UK CRAIG]

What would be better, a 1.4 or a 1.6 transfer box with 37" tyres on a Disco or Rangey 3.9 auto???????

Any help will be great, cheers.................

[Range Rover Blues]

You need to do the maths based on the rolling circumference but with an auto it's quite important you get the ratio right or it won't change up to top untill you are going too fast for those tyres.

If you don't want top end speed I'd go for the 1.6 so you have more power to get those tyres moving.  Unfortunately it makes no differnece to your low range so you won't enjoy as much engine braking.

[Bowie]

33" tyres with a 1.4 T-box works out almost the same as stock gearing, and gives me a lot of fun :)

I would say you need the 1.6 T-box, or, preferably change ring and pinion to a better ratio, this would help your low range as well as high :)

As RRB says, it's very important to get the gearing right in an auto, it not only mucks up your top end, but you end up with change points in stupid places, requiring too much throttle to kickdown etc, mine drove pretty horribly before swapping to a 1.4 from a 1.2, now it is *lovely* :)