Author Topic: Transverse ATTESA  (Read 912 times)

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scribble

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Transverse ATTESA
« on: 13 June, 2017, 11:18:54 PM »
Normally in a FWD each axle is connected to each side of the diff in the gearbox
With ATTESA it is the following
The front right axle is connected to the right side of the front diff in the transfer case
The front left axle passes through the centre diff (in the gearbox) and is connected to the left side of the front diff in the transfer case
The front diff unit has a shaft that passes through the centre diff and is connected to the left side of the centre diff in the gearbox
The rear diff is connected via the driveshaft into the transfer case which use a reduction/bevel gear that is connected to the other side of the centre diff
It's that bevel / reduction gear in the transfer case that matches the ratio of the rear diff and because of that there is no reason to change it.  If Nissan wanted longer or shorter final gear ratio's they just change it in the gearbox same as what is done with a FWD car.

In the simplest terms, if you think about a FWD car, the front left wheel connects to the left side of the diff in the gearbox and the right wheel to the right.  In the 4wd version the diff in the gearbox drives 2 other diff's instead, so is now called the centre diff.  Most other designs use the transfer case to split the drive, doing it the Nissan way allowed them to keep the part count to the lowest, since the gearbox is just basically just a FWD box with a transfer case bolted to it (although the 4wd box itself is a different casting to the FWD box so aren't interchangeable)
« Last Edit: 13 June, 2017, 11:21:26 PM by scribble »