front & rear axle diff gear ratio change FJ60 (1 Viewer)

[marc84FJ60]

hello all

With my cummins diesel repower I want to do everything to keep engine RPM low on highway.

I dont want to go too crazy on tall tires.

Does anyone have info on changing my gear ratios? Does anyone know what I have now in the axles? Its an 84 FJ60 wagon.

Lets say now I am 4.2:1 reduction in the differentials.

I want to go to a lower number say (for exmple) 3.5:1

Any suggestions are appreciated.

Thanks

Marc

 

[2mbb]

Don't know what you have but the stock differential gear in the FJ60 is 3.7:1. I'm not sure I've ever heard of a lower numerical gear ratio than this for the Land Cruiser.

Other than changing the gears your options to reduce rpm on the highway are bigger tires or an overdrive transmission. The H55F 5 speed transmission is a common upgrade for FJ60's.

 

[RredFJ40]

I don't know how far you are into your conversion but a Ranger Overdrive would help also, fits between your tranny and the engine and is built as a 350 to LC tranny adapter. you might be able to make it work. It's carried by SOR.