Thread: Changing Ratios

I run 33" on my standard gearing at the vehicle is fine. it's nice cruising on highways (due to the lower rpm) and tows the boat fine still. Admittedly I have some extra work - free flowing exhaust, tune and VNT.

I do intend on changing the gearing however as it lacks on hills or has to work reasonably hard even when unloaded.

Hello,
I am doing the same just ordering 3.9 ratio from GBR in Utah as they are about 9% lower so should be about the same as it is now a little less stress, was thinking about 4.10 or 4.11 but not sure how more this would rev ?? anyone would this a lower ratio be better ? I do a far amount of highway driving.
Ian

I'd say change the gearing if you can afford it. I run 245/75's (approx 31") on my V8 D1 and i would love to fix the gearing, i know lots will say they run the same size tyre as you, but we all expect different things from our vehicles and use them in different ways.
Why can you use a Defender transfer case?
I have one i will rebuild to put in my D1 soon.
How many KM's have you done?
Any noises etc from either transfer or diffs? That might help decide where to spend the money.

Originally Posted by justfishing

Hello,
I am doing the same just ordering 3.9 ratio from GBR in Utah as they are about 9% lower so should be about the same as it is now a little less stress, was thinking about 4.10 or 4.11 but not sure how more this would rev ?? anyone would this a lower ratio be better ? I do a far amount of highway driving.
Ian

Ian. Is this gears for transfer or for the diffs? Can you tell me the cost delivered and where from? PM if you don't wish to disclose cost.

Originally Posted by vogue

I'd say change the gearing if you can afford it. I run 245/75's (approx 31") on my V8 D1 and i would love to fix the gearing, i know lots will say they run the same size tyre as you, but we all expect different things from our vehicles and use them in different ways.
Why can you use a Defender transfer case?
I have one i will rebuild to put in my D1 soon.
How many KM's have you done?
Any noises etc from either transfer or diffs? That might help decide where to spend the money.

You have a D1 I am talking about a D2 where the Defender case can't go in a Disco. See here.
Disco II Transfer case VS Defender Trans case

I have no noises anywhere. It has only travelled 165,000, however it is starting to develop some leaks from the transfer, so it needs to come out.

Also, it would be far easier to do the transfer than two diffs.

Ashcroft transmissions in GB is my recommendation.
3.75 to run 32" tyres and 4.12 to run 33" tyres.
3.75 will put you almost at normal just a bit taller with the 32" tyres, the 4.12 is almost spot on with 33" tyres.

The R&P are much stronger too, so worth the effort.

There is a ratio calculator on Ashcrofts site so you can see what you need.

If you are going to tow, or get the most out of your upgrades for performance, then change your ratios to as near to standard as possible.....much friendlier for your gearbox.

Cheers
Kev

Originally Posted by Mr Whippy

Ian. Is this gears for transfer or for the diffs? Can you tell me the cost delivered and where from? PM if you don't wish to disclose cost.

Hello,
It is GBR GBR Product Catalog
These are diff gears comes with shims and seal they are $US299 + $US50 for shipping each so total landed is about $AU750 for 2 sets front and rear they got a few ratio's. They have Ashcroft 4.11 for $250 plus $50 shipping
Ian

Originally Posted by justfishing

Hello,
It is GBR GBR Product Catalog
These are diff gears comes with shims and seal they are $US299 + $US50 for shipping each so total landed is about $AU750 for 2 sets front and rear they got a few ratio's. They have Ashcroft 4.11 for $250 plus $50 shipping
Ian

I HATE YOU

I just found where I can spend more money
There is lots of very nice stuff in there....mmmmm

The 3.9 ratio for the diffs would be perfect for the 32" tyres.....I like the transfer case low range ratios too....expensive though.....aaaaaarrrgghhhh what to save for first