Stuart Knight

iTrader: (2)

Going to fit a 6MT to my MY94WRX and wondered what the rear diff ratio is as standard?

911

According to the book I'm looking at, the WRX to /sep 94 had a 4.111 : 1 diff, and the post Sept 94 had, it seems ,the same. The WRx diff went to 4.444 in Sept 96 on.

If you are fitting a 6 speeder, I think you should get the diff with it and the prop shaft AND the shift linkage!
911

stockcar

a lot we have worked on only have 3.9's..............think only the RA had a 4.11...................

alyn - asperformance.com

THE DEVIANT

My MY93 WRX has a 4.11:1. Take the back plate off and count the teeth on the 2 cogs. Mine was 37+9 which is 4.11:1.

dij

Sorry to hijack

is there a site or page that gives info on all types of diffs throughout the range?

I wanted to find out if what diff is in an sti 5 and if its the same as anything else.

Stuart Knight

iTrader: (2)

So I guess it all boils down to:

Which diff do I need with a JDM 6 speed box (non DCCD) bearing in mind I will be fitting it to my MY94 WRX?

Cheers

Stuart

Rob99

Any easy way to check your current diff ratio

Jack up the car so all four wheels are off the floor.
put car in neutral with handbrake off
Mark the prop shaft at any point.(use one of the bolts to the diff)
Turn one of the rear wheels through 360 degrees and count how many times you see the mark appear.

Just less than 4 times = 3.9 ratio
just over 4 times = 4.11
almost 4.5 times = 4.44 ratio

dij

[QUOTE=Rob99]Any easy way to check your current diff ratio

Jack up the car so all four wheels are off the floor.
put car in neutral with handbrake off
Mark the prop shaft at any point.(use one of the bolts to the diff)
Turn one of the rear wheels through 360 degrees and count how many times you see the mark appear.

Just less than 4 times = 3.9 ratio
just over 4 times = 4.11
almost 4.5 times = 4.44 ratio

[/QUOTE
So what youre saying is there is only 3 types of diff/ratios?

Is this throughout the range ie all classics and newage?

Bats-Wrx

iTrader: (1)

Stuart a 3.9 diff as long as its in a R160 case is what is needed for the 6 speed.

Rob99

[QUOTE=dij]

David_Wallis

I wouldnt recommend the turning the wheel method, its been discussed in other threads..

Count the teeth for the definitive answer.

911

Agree with David.
You can just about do the trick by removing the filler plug out of the diff with the car jacked up at the rear (oil won't come out then)
Clean the tooth visible on the crown wheel and tippex a mark on it.
Mark the propshaft similarly.
Turn the prop and count the turns until the tippex mark arrives back at the same spot you started.
You then use the ratio:

just more than 4 turns, ratio is 4.111
just under 4 turns, 3.9
more than 4 turns by quite a bit (very technical, you work out the degrees of turn!) ratio is 4.444.

I have actually done this, but the diff was out of the car.

911