Gearing question

Check out this site: https://ashcroft-transmissions.co.uk/ratio-calculator/

Thanks OneTen, but I don’t know what diff ratio I have. That’s what I’m trying to figure out lol

3.54 diff ratio.

Did any civilian LRs come with any other axle ratio?

LRNAD90 said:

Did any civilian LRs come with any other axle ratio?

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No 90/110/139 or defenders came with different axle ratios afaik. The ratio changes seem to have been limited to the center differential.

Ok perfect. So 1.410 T box with 3.54 gears in a 300tdi. Could I run 35s efficiently? Or would it struggle?

On an LT77? I'm amazed you haven't destroyed it yet.

The gearing on the LT77 is shorter than the R380 - to keep the same speed, you need to wind it up more - about 250 rpm more for the same top speed. More speed = more fuel. More fuel = more heat.

Well I don’t have 35s on it now. So are you saying a LT77 can’t run 35s without “destroying” it?

It'll certainly struggle with 35s and stock gearing, but that's not to say it cant be driven like that. Just make sure you have enough lift.

Ok that’s what I was wondering. Would you suggest 4.10 gears or maybe even lower?

4.10s will help, without screaming on the highway. Though, you'll be driving a 110 on 35s with a tdi, it's going to scream on the highway regardless

Yeah I think 4.10s will be the way to go. I’ll be driving this primarily off road. Maybe 25% on road driving and that’s it.

I run a 200tdi with a 1.4,4.12 gearing with 37s . It does ok on hwy 3k RPM right at 70 mph but i have a stubby r380 . Dont forget if your running 35s shes going to need HD cv's and halfshafts,driveshafts and diffs would be a good idea. unless its just a mall cruiser

35s are fine with that setup. People are not paying attention to the gearbox.

Why do you have a pre Defender gearbox in a 1993 truck?