Lower diff ratios - auto transmission

vincentvega · Post by **vincentvega** » Wed Nov 30, 2005 10:11 am

With all the current work being done on lowering diff ratios and low range gearsets in manual boxes, I have started thinking about modifying my auto. I currently i have an EJ22 lib with a 4.11 AWD auto. The rear diff is an open 4.11.

I have access to a dead 4.444 turbo box for parts, and 4.444 viscous diffs are easy to come by. What i dont know is how much work is involved in fitting the 4.444 crown into my 4.11 box?

Currently i run 26" road tyres (6% speedo error) and 27.5" offroad tyres (10% error). If i understand this right, changing to 4.444 diffs will give me a 7.5% gearing reduction, and will mean that i can pretty much drive to the speedo regardless of which tyres im running.

What do you guys think? Worth doing? Am i likely to notice the difference in gearing? The car currently feels a bit over geared around town, and it cant hurt offroad either.

Xtreme_RX · Post by **Xtreme_RX** » Wed Nov 30, 2005 11:02 am

Dane,

It is very doable BUT you will need to pull the front of the auto to bits.

PM me & will tell you more...

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Wed Nov 30, 2005 11:06 am

Yes you will notice the difference and it is pretty much straight forward to do you will however need a different tailshaft at the 4.44 diffs have a square bolt pattern on the diff and yours will be a rectangle pattern. An you will have to pull the gearbox out.

steve_rising_sun · Post by **steve_rising_sun** » Wed Nov 30, 2005 7:50 pm

Easy job, but speedo will read the same, ie too slow with bigger tyres
Steve

vincentvega · Post by **vincentvega** » Thu Dec 01, 2005 8:32 am

Can you elaborate steve?

Is the speedo on the output shafts meaning the lower diff ratio doesnt affect it?

Xtreme_RX · Post by **Xtreme_RX** » Thu Dec 01, 2005 10:06 am

There is the speedo driven & drive gears.

The drive gear is on the drivers side of the diff - on the output shaft inside the box. If you undo the cover around the drivers side out put shaft & look in you will see the gear. This then faces to the drive gear which gives you your speedo read out. The ratios are the same for 4.111 to 4.444.
As the 4.444 boxes ran a 15" rim but had the same rolling diameter as the 14"

Outback bloke · Post by **Outback bloke** » Thu Dec 01, 2005 3:45 pm

It is possible to get early model 4.44 rear diffs that will match your tail shaft. If you can find one form a Jap importer that came with a turbo auto front cut it will be spot on and limited slip.

steve_rising_sun · Post by **steve_rising_sun** » Tue Dec 06, 2005 5:16 pm

The ratios do vary, early RS had 14" and 444. Early GX also had 14" with 4.11. I have only got 12"
Steve

Guest · Post by **Guest** » Sat Dec 24, 2005 12:13 am

What would one pay for a 4.44 auto with the works - viscous centre LSD and I'm assuming one would also convert to a front LSD while they were at it. Is it possible to lock the centre diff in these boxes?

steve_rising_sun · Post by **steve_rising_sun** » Sat Dec 24, 2005 8:41 am

I have later 444 autos from the twin turbo, they fit straight in. Autos do not have centre diffs. You can lock the rear cluch pack for off road.
$900.
Steve