Anyone changed 2wd diesel hilux diff ratio ?

[AE85.6]

Just wandering if anyone has already been through this saga already ?
and what ratio gave what results.

Basically just trying to get the revs down a lil for motorway driving.
100kph in top gear is 3000 rpm which is pretty high, even if I could drop 500 off would be a lot better.

Checked the build plate hoping to see diff ratio code but only had g52 with nothing after it ? so im not sure what is actually in there now, I guess I may not without pulling it out to count teeth ?

Cheers

[mjrstar]

sounds similar to the hilux diff i have in the starlet which is a 3.9 although depending on your tire size it could be a 4.1.

[AE85.6]

Forgot to mention that which was prob quite helpful ay, tire size is 205/65 r15.

Thought it could be even higher ratio as 3k in the diesel is quite up there !

[strx7]

I'd say its currently a 4.3, putting a 3.7 in there would drop it back to around 2550rpm @ 100

[QikStarlie]

jack it up and spin drive shaft see how many rotations you get per turn of wheel. easy

[matt dunn]

Checked the build plate hoping to see diff ratio code but only had g52
Cheers

Isn't that the gearbox code? Should still have a diff code?

[AE85.6]

Cheers all,

Will have a look at turning the wheel to drive shaft next time I go to the vehicle or get it out of storage.

Will keep my eye out for lower ratios just wasn't to sure how common they were in a hilux head or what I could steal one from that will work ?
I assume as you cant swap an irs "T" or "F" series head straight into a solid rear end its the same with "G" series ? but if the better ratio's are ex supras or something similar (IRS) can I still use the crown wheel gear from them ?

and yes matt I thought G52 was gearbox and then should be a G??? after that for diff ratio and lsd/open etc, my old surf did however ute says nothing more ?

[Rick]

Isn't that the gearbox code? Should still have a diff code?

Yes that could be the gearbox code but if it was G052 then it would be a 2 Pinion 3.7 ratio diff

[strx7]

i have seen nz new hilux's which just have G52 as the box code and nothing for a diff code.

taller diff heads are easiest to find in IRS G series. 3.5 and 3.7 hilux diff heads are out there but they are worth good $$$ if people know what they are worth

[AE85.6]

Found this calculator that had toyota g52 box listed:
http://www.grimmjeeper.com/gears.html

more for 4x4 stuff but you can skip some of the low ratio and other bits,
so for tire size on mine at the mo comes up with a ratio of 4.5 for 5th gear and 3000 revs.

Changing ratio field to 3.9 gives about 2600 revs and 3.7 was 2500 ish which both sound better, not sure how common these ratios are...

found a code to ratio chart also so maybe something with a code beginning G05-7, G30,1 pick a part mission may be on the cards.

strx7:
cheers for that and I did read on one of the auzzie 4x4 sites that some of the petrol v6 surfs etc had lower diff ratios, dunno how acurate that is though as would have thought they would be a lot higher as still a 4x4 unless they have crazy gearbox ratio to suit ?