Gen3 Auto 3.0 diesel on 285/75/16's. with a 4.1 diff what ratio would be best?

[TrunksGen3]

Hi all,

I'm in the UK running a Gen3 Auto 3.0 diesel on 285/75/16's. with a 4.1 diff.

Can someone please explain to me what the benefits/disadvantaged are of changing to a different ratio, eg 4.88 in an auto.

I have read so many articles on this forum, but most seem to be discussing the benefits for manual gearbox, petrol trucks, not auto.

I've just ordered a TrueTrack for the rear and am wondering if it's worthwhile re-gearing at the same time?

Thanks

 

[octanejunkie]

4.3 would probably be better but 4.1 is fine, it really depends on your use of the vehicle and expectation for performance and fuel economy; which is very subjective.

Regarding mileage and differential service, if you have high mileage/old gears it is often not worth spending the money on setting up old gears on a new diff - this is again a subjective issue but there is a common sense/financial argument to consider

What is your intended use of the vehicle, majority of the time?

 

[phattyduck]

Gearing needed will be highly dependent on ideal engine RPM - pretty much none of us on here have the diesel, so it will be hard to get good advice on that...

What's the redline on the motor? What RPM do you want to cruise at on the highway in top gear? Was the 4.10 stock gearing? I'm surprised it was that high (numerically) from the factory with a diesel engine.

-Charlie

 

[HiluxSurf SSR-G]

redline is 4400 rpm. 100 kph (62 mph) is at around 1800 rpm flat highway

most came with a fgr of 4.10:1 although a few came with 4.30:1