4motion tread depth

[doncarlyon]

What is an acceptable difference in tread depth between front and rear axles?

Lots of differing advice online as always. So looking for some real world examples / advice from those with a 4motion transporter.

 

[Sasquatch]

It depends on who you ask. Haldex reckon 2mm across the axle, 3mm fore-aft but I think VW-Audi recommend slightly different.

I believe it's less critical with Haldex than it was with the (highly excellent) TorSen diff system of older generations.

 

[doncarlyon]

Fairly certain the RS3 i have states that each axle has to be fairly close but no mention of front to rear variance. I'll double check that though.

 

[Sasquatch]

Fairly certain the RS3 i have states that each axle has to be fairly close but no mention of front to rear variance. I'll double check that though.

It was 3mm on my Volvo with Haldex constant traction.