Diff Ratios

GK · 09-11-2007, 11:42 AM

What are the diff ratios for AUs?

Is the wagon and sedan different? I'm assuming yes, and I would doubly assume yes again for ute diff ratios. However, as has been the case many times before, assumptions can be based upon anything but reality! LOL!

Can someone please list the ratios for each sedan wagon and ute and also a list of all available ratios?

I will need to replace the diff in the sedan soon, and wouldn't mind a better ratio.

BTW, I did do a search and didn't get any definitive answers.

Cheers,

GK

ClassicAU · 09-11-2007, 12:25 PM

From what I know George, your wagon should have a 3.23 open diff, and the sedan a 3.08 open.

Also, if you were to get a new diff, the factory LSD is a 3.45 ratio.

Evan

GK · 09-11-2007, 12:44 PM

Thanks Evan, I just want something a bit lower than what I've got. I'm not going the LSD, but might hunt around for a wagon item. If the ute is lower again, I might go for one of those.

I'd still like a list of available ratios and what was on each AU though. AFAIK no one has put one together yet. It'd be a handy resource I'd reckon.

GK

ClassicAU · 09-11-2007, 01:09 PM

I dont think anyone has put a list together because, as far as i know, there is only three ratios available in the entire AU series, ute, sedan and wagon. 3.08, 3.23 and 3.45 LSD. Anything lower would be after market i think.

Evan

sly · 09-11-2007, 03:27 PM

All wagons are 3.23... not sure about utes, would guess at 3.23 as well. Sedans varied, AFAIK Forte & Futura had 3.08, Fairmonts 3.23 due to extra fruit. XR6's had 3.45's and IIRC so did Fairmont Ghias. Those are your choices if you want to pick one up from a wrecker, but you can get any ratio available in either open or LSD if none of those suit. I saw an XR 3.45 diff centre advertised recently, I think it was $200 or $300, may have been in the current "Just Parts".

GK · 09-11-2007, 04:23 PM

Cheers Sly!

GK

EF Futura 07 · 09-11-2007, 06:46 PM

hi, you can also go 3.7, 3.9 or 4.1 if you want.

Black XR · 09-11-2007, 08:27 PM

how do the 3.7 or3.9 effect fuel economy

EF Futura 07 · 09-11-2007, 08:52 PM

Quote:

Originally Posted by Black XR

how do the 3.7 or3.9 effect fuel economy

hi, check out this site http://users.tpg.com.au/leeton1/calculator1.htm

since your is an XR it has a 3.45 standard, so you probly wouldnt get much gain out of a 3.7 (yes there will be some but if you go 3.9/4.1 you will have a much better takeoff) unless yours is manual the 3.9/4.1 is way to low

Black XR · 10-11-2007, 12:10 AM

Great calculator but it doesn't realy tell me much about the fuel economy side of things

StealthAu · 10-11-2007, 12:13 AM

depends on what sort of driving you do, on the high way you'll notice the differance, but around town you wont

private9 · 10-11-2007, 12:21 AM

Quote:

Originally Posted by ClassicAU

From what I know George, your wagon should have a 3.23 open diff, and the sedan a 3.08 open.

Also, if you were to get a new diff, the factory LSD is a 3.45 ratio.

Evan

That what I believe the ratios are too.

My wagon has a factory LSD, so would this be a 3.23 or 3.45?

Dark Horse · 10-11-2007, 02:43 AM

Factory Diff ratios:

3.08 SS:
I6 Auto Sedans
3.23 SS:
Wagons, Manual I6 Sedans, V8 Sedans and Utes or
3.45 SS:
Late Edition AUII XR6 HP, AUIII XR6 HP Sedan (unless otherwise optioned) and IRS Sedans
3.45 LSD:
All AUI XR6 HP Sedans and early build AUII XR6 HP (Pre May '01 builds) sedans, all XR utes, all XR IRS Sedans, All T Series, utes with one tonner suspension option. As far as I know, any factory fitted LSD is 3.45 ratio.

sly · 10-11-2007, 08:57 AM

Quote:

Originally Posted by Dark Horse

Factory Diff ratios:

3.08 SS:
I6 Auto Sedans

Interesting. I'm almost certain that Fairmont I6 sedans ran the 3.23 due to extra weight so as not to feel slow compared to the lighter Forte/Futura. And I'm damn sure the VCT Ghia came from the factory with 3.45's.

Is your info from a workshop manual, specs website or similar?

Sometimes even the supposed experts have incomplete info. I've had a running battle with NRMA over the spec of my Smartshield update series 1. They cannot be told that later s1 cars had the immobiliser and front power windows stock from the factory, they have to be counted as "accessories" which reduces the value of mods I can make to the car before they won't insure it. Apparently Ford never officially informed them of the change in equipment levels...

private9 · 10-11-2007, 11:31 AM

Quote:

Originally Posted by Dark Horse

Factory Diff ratios:

3.08 SS:
I6 Auto Sedans
3.23 SS:
Wagons, Manual I6 Sedans, V8 Sedans and Utes or
3.45 SS:
Late Edition AUII XR6 HP, AUIII XR6 HP Sedan (unless otherwise optioned) and IRS Sedans
3.45 LSD:
All AUI XR6 HP Sedans and early build AUII XR6 HP (Pre May '01 builds) sedans, all XR utes, all XR IRS Sedans, All T Series, utes with one tonner suspension option. As far as I know, any factory fitted LSD is 3.45 ratio.

So, in theory, I have a 3.45 LSD in the wagon then? Certainly doesn't feel it, but I guess it's lucky I haven't picked up a 3.45 centre yet!

If the diff has a tag with the ratio on it, I might get under there today to confirm!

EF Futura 07 · 10-11-2007, 04:26 PM

PRIVATE9: if you have a 3.45 1st gear should rev out @ 78-80ks and not 88ks like a 3.08

EF Futura 07 · 10-11-2007, 04:29 PM

Quote:

Originally Posted by Black XR

Great calculator but it doesn't realy tell me much about the fuel economy side of things

depending on auto/manual, driving style, air con on/off and what size tyres your running, then each raito swap (ie going from 3.45 to 3.7) will take out around 20km's out of a tank

The Monty · 10-11-2007, 05:09 PM

The Au1 Fairmont runs the 3.08 diff gears as well, its the ghia that has the 3.23's.

**Stav** · 10-11-2007, 05:30 PM

Quote:

Originally Posted by Black XR

how do the 3.7 or3.9 effect fuel economy

No real difference to 3.73 ratio mate.If anything my fuel economy was better than stock.

4:11 ratio does affect fuel economy.

Dark Horse · 11-11-2007, 02:42 AM

Firstly Stav, I heard and then saw your blue wagon eastbound on the M4 coming up in the left lane on Thursday. It is the loudest six cylinder AU Falcon I have ever heard.

Ok, back on topic.

Quote:

Originally Posted by sly

Interesting. I'm almost certain that Fairmont I6 sedans ran the 3.23 due to extra weight so as not to feel slow compared to the lighter Forte/Futura.

Yeap, I overlooked that one. They did run a 3.23 final drive ratio.

Quote:

Originally Posted by sly

And I'm damn sure the VCT Ghia came from the factory with 3.45's.

VCT Ghia's have IRS, yeah? And if so:

Quote:

Originally Posted by Dark Horse

Factory Diff ratios:

3.45 SS:
Late Edition AUII XR6 HP, AUIII XR6 HP Sedan (unless otherwise optioned) and IRS Sedans

Quote:

Originally Posted by sly

Sometimes even the supposed experts have incomplete info. I've had a running battle with NRMA over the spec of my Smartshield update series 1. They cannot be told that later s1 cars had the immobiliser and front power windows stock from the factory, they have to be counted as "accessories" which reduces the value of mods I can make to the car before they won't insure it. Apparently Ford never officially informed them of the change in equipment levels...

Yes very true, it is a joke when Ford AU make changes on a whim like that and don't tell anyone, adding unnecessary frustration to the owners.

Rebel · 11-11-2007, 08:58 AM

Just a question a little off topic, in a AUII XR8 220, is the LSD a clutch pack type or a cone type?

**Mechan1k** · 11-11-2007, 09:05 AM

Quote:

Originally Posted by Dark Horse

Factory Diff ratios:

3.08 SS:
I6 Auto Sedans
3.23 SS:
Wagons, Manual I6 Sedans, V8 Sedans and Utes or
3.45 SS:
Late Edition AUII XR6 HP, AUIII XR6 HP Sedan (unless otherwise optioned) and IRS Sedans
3.45 LSD:
All AUI XR6 HP Sedans and early build AUII XR6 HP (Pre May '01 builds) sedans, all XR utes, all XR IRS Sedans, All T Series, utes with one tonner suspension option. As far as I know, any factory fitted LSD is 3.45 ratio.

Then to add to this ... there was factory optioning as well ... as you could option shorter ratios on some models ... and option LSD as well.