anyway to tell hilux diff ratio

[nibbsy]

i have a 89 hilux, just wondering if there is anyway to tell what ratio the diff is with something like a number or marking on the diff itself, cos i am running a v6 and it LOVES a drink.
If it is a 4.8 i can swap it down to a 4.3 which will help, are there anyother lower ratios available that anyone knows off??
thanks
nibbsy

[Lux_89]

4.1 i think m8, just pull ya diff out and count the teeth... or ya can do something with the plate on ya firewall and look up the code somewhere on here or the net and it will tell ya, what did it have in it b4 the v6? if it was 2.8 diesel it will be 4.3 if they are stock ring and pinion

[v6hilux]

If you don't have the Axle Codes from the Silver plate on the firewall, or you suspect the ratio has been changed in the past. Here is a method to tell.

I used white liquid paper correction fluid for the experiment with a small mark on the diff housing and another on the adjacent rotating pinion seal protector that turns with the driveshaft. With one wheel 0n the ground and the other in the air, I turned the wheel in the air and counted the turns until I got the marks to line up again, exactly.

The 4.3:1 was 43 driveshaft rotations to 20 free axle rotations - (43/20)x2=4.3

The 4.55:1 was 41 driveshaft rotations to 18 axle rotations - (41/18)x2=4.55

Conclusion - This method of measurement is extremely accurate and saves opening a diff. When dealing with an IFS diff "on the bench", it's easy to do alone with pen and paper to count revs as the white marks rotate and line-up. I suggest a helping hand if possible when it comes to more difficult situations.

On a mission, I did some quick calculations and came up with these figures for other common ratios. They might be wrong - 4:1 count = 40 & 20, 4.1:1 count = 41 & 20, 4.88:1 count = 44 & 18

After spending money on replacement diffs going on info from the Axle code, wouldn't it be embarrassing if it had a ratio change before you bought the car.

Here is some info on Axle codes;

EG- G294, 8 inch, 4.1, 4 pinion open diff

First Letter, Denotes
Gear Size

07 = 3.900
08 = 4.110
10 = 4.375
14 = 4.875
25 = 4.556
28 = 4.300
29 = 4.100
31 = 3.91
38 = 3.42
43 = 3.56
54 = 3.90
66 = 3.07

2 = 2 Pinion, Open Diff
3 = 2 Pinion, Limited Slip
4 = 4 Pinion, Open Diff
5 = 4 Pinion, Limited Slip

F = 7.5" gear

G = 8.0" gear


While many 2WD models did get the 7.5" gears, many
also got the 8" rear diff. It's not clear which models got
these, besides the 1 ton models, but I've seen 8" diffs
installed from the factory on several base model 1986
Toyota 2WDs.

A = 2 Pinion, Open Diff?

B = 4 Pinion, Open Diff?

C = 2 Pinion, LSD ?

01 = 3.42
02 = 3.58
03 = 4.10
04 = 4.56
05 = 3.15
06 = 3.91
07 = 4.30*

[spongerx]

Once you dont have an LSD or auto-locker v6Hilux's method works well. I put 8 chalk marks on the pinion flange to increase the accuracy (1 longer than the others), 1 on the 3rd member and 1 on the tire that's being rotated. You need to do 2 full revolutions of the tire and then count how many times the long mark on the pinion flange passes the mark on the 3rd member then use the other marks to determine the rest of the ratio.

[nibbsy]

thanks for the info guys, according to the tag it is a 4.3 lsd
not sure if it has been changed or not, have to chuck a bit of a skid and find out if its a LSD or not
do you think changing to a 4.1 would drop the revs by much?
I have 32's on it atm until they run out of tread, then i will go up to 33's which will also help so the 4.1 could help again.
thanks again guys

[v6hilux]

have to chuck a bit of a skid and find out if its a LSD or not

If it hasn't been rebuilt in the last 20,000 then it's probably worn out. Those Toyota LSDs are a POS!