Hilux diff ratios.

[wheel rim]

My latest toy is a 1986 duel cab hilux with a 5 litre holden V8 in it.As you can imagine it is rather heavy on fuel.I am considering changing the diff ratios to drop the engine revs when cruising.
At 100 kmh the engine revs at 2600 rpm.I am told that the engine returns its best economy at 2000 rpm and under.It currently has 4.55 diff ratio in it and I am loking at putting 4.1's in it.It has a dyna gearbox in it which has a very low first gear so when in low range it is very low speed so the taller diffs should not concern me there.
Has anyone played with these before and is the upgrade worth while.

Cheers,
Wheel Rim.

[2jzhilux]

mate i say do it i changed my diff from a 4.1 to 3.9 and you could tell the difference even with the 22r
be wary of the late and early model hiluxes have different housings i swaped a 4.8 centre to a 3.9 and had to change the housing due to it having an offset pinion for the higher ratio not sure if 4.55 is the same

[J0RD0]

3.9 makes good cruiser, must be quickish with those 4.5 gears?

[wheel rim]

OK cool, seemed like it would work.I will make sure of the fit as you have mentioned.

[wheel rim]

Jordan,
I thought 4.1 was quicker (higher speed) than 4.55. Therefore wouldn't it drop the engine revs??

[2jzhilux]

also the lower ratios will help with the extra torque of the v8

[Norbie]

With an engine like that you'd want to be going taller than 4.1:1 IMO. Something like 3.7:1 out of an auto MA70 turbo would work well I think.

[wheel rim]

MA 70 ok I shall do a ring around tomorrow.

[2jzhilux]

do a search on ebay for motive gears thats where i got mine from
brand new crown wheel and pinion for 490 something
and it arrived in a day and a half
he also has lower ratios aswell like 3.5 3.25

[badboybubby]

Ive got a 2.78 if anyone wants to swap

[bugeyedcreepy]

Ive got a 2.78 if anyone wants to swap

so, what would you swap for...? are G Series *A70 gearsets compatible to hilux G Series??

[urantia]

anyone know if the hiace 1990-98 shares the g series diffs like the hilux?

[2jzhilux]

yes........

[urantia]

ha ha thanx, still a newb with hiaces/hilux's and exactly how much they have in common.