JohnD

iTrader: (5)

What are the differences between the "Suretrac" system in the 03 STi and the standard sealed viscous units in the WRX and earlier models? Are the Suretrac units also sealed and therefore do not require LS specific gear oil as would, I assume, the latest DCCD units in 05 cars?
I'm about to do a gearbox and rear diff oil change and to be absolutely sure about the fluid spec. for this model.
Cheers JohnD

ex-webby

John,

Does it not state in your owners manual?

Regards,
Shaun.

Chelspeed

AP Suretrac are not sealed like the viscous coupled LSD's, the limited slip bit forms part of the normal diff and is immersed in the normal diff oil.

But the way they operate, with gears rather than clutch plates, means they don't need lsd specific diff oil. I'd just go for a good quality synthetic diff oil.

JohnD

iTrader: (5)

The handbook does not differentiate between WRX and STi in fluid recommendation, just capacity difference between 5 and 6 speed boxes.
I've learnt not to totally trust the handbook in giving all the information we desire!
Cheers Chelspeed!

JohnD

Engineer@Uni

I believe there is a Suretrack only in the front, and this has now been upgraded with a Helical LSD up front in the MY05 STi

JIM THEO

Until MY05 STI uses front-rear Fuji Univance Suretrack differentials (MY01-04), the last one STI uses plate rear, worm gear (Quaife like) front.
There is available same type mechanical differential for the front of WRXs and of course it's still available from previous generations STIs the plate type for the rear of the WRX.
JIM