4WD Yaris / Vitz questions

[CTScott]

Originally Posted by Swing

Ok I see it now.

I could not find it because I was checking the rear diff of a first gen Vitz 4wd, it does not have this coupling assembly in the rear. It may have something funny around the prop shaft, but I'm not sure if that's a coupling assembly (it's not called that way)
So it is a bit unclear on the first gen Vitz.

But for the automatic gen 2 Vitz 4wd I see the coupling assembly.
ALso the gen 3.

But the gen 3 has to button to lockup the middle (see previous page youtube), so I would assume it is an electromagnetic coupler (at least in the gen 3) instead of viscous.

And to mee it still seems if it takes the power from the left front driveshaft. So (without LSD) it would mean that if the right front wheel is loosing traction and spinning, the rest of the wheel wouldn't get any power?

Not off the front left, but rather off the ring gear of the outside of the front diff. The front diff is just the normal front diff with a modified housing for that portion of the tranny.

Correct on the 3rd gen - It does look like they added the electric lockup.

[Swing]

Originally Posted by CTScott

Not off the front left, but rather off the ring gear of the outside of the front diff. The front diff is just the normal front diff with a modified housing for that portion of the tranny.

Ok I can't see that from the partssystem, but that sounds more credible. Otherwise it would be a worthless system.
Maybe this part 41319-52011 (3rd gen Vitz) in fact turns around the driveshaft but is not connected to the driveshaft? (because it is connected to the front diff housing/ring)

So they can have a different speed, even though it looks like one axle.

Originally Posted by CTScott

Correct on the 3rd gen - It does look like they added the electric lockup.

Ok, so you say that the 2nd has viscous coupling. I can believe that, but it is really hard to say from the parts catalogue (the coupling assembly really looks the same as the 3rd gen with electric coupling)

On the 1st gen there might be something funny in the propshaft, but it could just be some holder for a bearing. So I'm not sure how that one works.

To be honest I still think all generations have an electric coupling assembly with a button, but I could be very wrong about it

Any setup using viscous coupling could be nice for high power awd (like a Celica GT4).
A fixed electromagnetic coupling is nice for dirt roads, not nice for high power awd (it isn't even awd anymore, it would be parttime 4x4 then). But it would be nice to have it fixed into a rear wheel drive Yaris.

[CTScott]

Originally Posted by Swing

Ok I can't see that from the partssystem, but that sounds more credible. Otherwise it would be a worthless system.
Maybe this part 41319-52011 (3rd gen Vitz) in fact turns around the driveshaft but is not connected to the driveshaft? (because it is connected to the front diff housing/ring)

So they can have a different speed, even though it looks like one axle.



Ok, so you say that the 2nd has viscous coupling. I can believe that, but it is really hard to say from the parts catalogue (the coupling assembly really looks the same as the 3rd gen with electric coupling)

On the 1st gen there might be something funny in the propshaft, but it could just be some holder for a bearing. So I'm not sure how that one works.

To be honest I still think all generations have an electric coupling assembly with a button, but I could be very wrong about it

Any setup using viscous coupling could be nice for high power awd (like a Celica GT4).
A fixed electromagnetic coupling is nice for dirt roads, not nice for high power awd (it isn't even awd anymore, it would be parttime 4x4 then). But it would be nice to have it fixed into a rear wheel drive Yaris.

The 2nd gen was definitely not switchable. I seriously looked into importing the parts from one to convert a US one back in late 2009, but abandoned the idea when I found out that the chassis was different (tunnel) and that you had to also import the entire AT, as the transfer case assembly is custom fit to it at the factory.