How to work out what diff ratio you have?

[Robbman]

Well JZA70's were never sold domestically in Australia or USA.

So someone is wrong.

What kind of retarded statement is that? Just becuase a car isn't sold somewhere doesn't mean you can't get specs for it. We're thousands of miles (or kilometers) apart, yet we're communicating just fine thanks to the internet...


Anyway, my non-US info was taken from GA70 and JZA70 owners from various forums who have posted their ratios...

My US info was taken from my backyard...

[The Witzl]

.... umm on a T series ring gear it actually states the number of teeth both it and the matching pinion gear has, thus giving the ratio.....


DONGGGGgggg!!11oneeleventy

[Robbos_Toyotas]

.... umm on a T series ring gear it actually states the number of teeth both it and the matching pinion gear has, thus giving the ratio.....


DONGGGGgggg!!11oneeleventy

T series are teh ghey with aids tho so have you actually worked out what it is yet glen?

[oldcorollas]

meh, it's also on B and U series

methinks it is standard practice to stop morons at factory from packing wrogn gears together

[BlackSupra]

What kind of retarded statement is that? Just becuase a car isn't sold somewhere doesn't mean you can't get specs for it. We're thousands of miles (or kilometers) apart, yet we're communicating just fine thanks to the internet...

Im just saying that there is not a specific model JZA70 for the US and a seperate one for Australia as they were only ever released JDM.

You both agree on the auto ratio, yet the manual ratio differs. I highly doubt that toyota would have run with 2 seperate ratios for the manual (independant of country as they were only released in Japan).

JZA70 man ran a 3.7
JZA70 auto ran a 3.9

JZA70 manuals had a 4.10 Torsen
JZA70 autos had a 3.91 Torsen

And i'm 'pretty sure' it's a 4.1 ratio in the JZA70 manual.

I just don't want to spread miss-information unless we are 100% positive in the tech section.

[Robbos_Toyotas]

Im just saying that there is not a specific model JZA70 for the US and a seperate one for Australia as they were only ever released JDM.

You both agree on the auto ratio, yet the manual ratio differs. I highly doubt that toyota would have run with 2 seperate ratios for the manual (independant of country as they were only released in Japan).





And i'm 'pretty sure' it's a 4.1 ratio in the JZA70 manual.

I just don't want to spread miss-information unless we are 100% positive in the tech section.

it does not make a pinch of shit's sense that toyota would use a shorter diff in the manual on a 1jz, but have longer ones for every other motor/ manual box combo the supra came with. Hence i think its either a 3.9 or a 3.7

[1200det]

The ratios for the JZA70 were

5 Speed = 4.10
Auto = 3.909



.

[1200det]

MA70

1986 - August - 1988

5 Speed = 3.727
Auto = 3.909

August - 1988 - May - 1993

5 Speed and Auto = 3.727

JZA70

5 Speed = 4.10
Auto = 3.909



.

[Robbman]

I just don't want to spread miss-information unless we are 100% positive in the tech section.

Got ya there.

[EldarO]

MA70

1986 - August - 1988

5 Speed = 3.727
Auto = 3.909

August - 1988 - May - 1993

5 Speed and Auto = 3.727

JZA70

5 Speed = 4.10
Auto = 3.909



.

Jap Spec 1990 MA70 Auto here with 3.7 LSD

Eldar.O.

[Robbman]

it does not make a pinch of shit's sense that toyota would use a shorter diff in the manual on a 1jz, but have longer ones for every other motor/ manual box combo the supra came with. Hence i think its either a 3.9 or a 3.7

Sure it does...
Same reasons US NA MA70s came with 4.30s and others got 3.90s...

[whatthe?]

I think what he's trying to say is that it seems a little strange to have a taller ratio in a car with a 4 speed (effectively) auto than a car with a 5 speed manual unless they wanted to make a 0-60 in 14 second car with a top speed of 200mph . I'm not arguing though, because I honestly dont know

[BlackSupra]

Ok well its confirmed.

It IS a 4.1 ratio.

Now the other thing i noticed is that the axles don't spin at all independantly.... So i can only assume this is now a 2 way centre?

Any help on that?

[Robbman]

Is it a IRS rear-end?

[oldcorollas]

clutch pack can be preloaded. so regardless of number of ways, it may not turn easily by hand.
pull the filler plug, see if you can see thru the holes in the centre what the angles are..

ie

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