Nissan Patrol 4x4 (Africa)

ahhh...yeah sorry.... My definition of the locked center diff was completely wrong choice of wording. Like you said its not a diff in the conventional meaning or look or working. My understanding is exactly like you said Peter, its purely a coupling of the front and rear propshafts to rotate at the same speed, without any slipping or transferring of power.

So if your rear tyres are more worn than the front tyres, in theory the front tyres will constantly be scrubbing to keep up with the rear tyres rotation.

ricster wrote:...So if your rear tyres are more worn than the front tyres, in theory the front tyres will constantly be scrubbing to keep up with the rear tyres rotation.

Yes, and I am sure this is very bad for your drivetrain.

So how does wind-up happen?
Lets suppose I am in 4x4H on tarmac, and I make crop circles (Like Tinus in the river).
Will I eventually brake something?

Alex Roux wrote:

ricster wrote:...So if your rear tyres are more worn than the front tyres, in theory the front tyres will constantly be scrubbing to keep up with the rear tyres rotation.

Yes, and I am sure this is very bad for your drivetrain.

So how does wind-up happen?
Lets suppose I am in 4x4H on tarmac, and I make crop circles (Like Tinus in the river).
Will I eventually brake something?

Nee want jou wiele gly....problems kom in wanneer jy draai en jou wiele kan nie gly om te kompenseer vir slip nie

We had a Hilux with us at Berakha a few years back. Within about 2km of the trail, he blew up his front diff. While we were standing around the vehicle, I noticed the front wheels were smaller than the rear wheels. Inspected it properly and saw front had 245's, and the rear 31". Rear was MT's and front was AT's.

The result of the bigger tyres on the rear, was that the front diff was running on the "reverse" side of the ring gear for 2km. And that is all it took to explode it.

Also the reason I will never recover in reverse if I can help it. The diff is constructed to take "most" its work load forward, not in reverse. Strangely enough, the Hilux broke/shattered it's spider gears. They conveniently went to lay in places in the pumpkin that locked the diff up preventing the wheels from turning totally.

Another reason why your tyre rotation schedule should include the sparewheel coming into the mix so that it wears down with the other wheels. On big MT's with 12-16mm deep tread, a worn tyre compared to a new one, can make a fair difference in the rolling distance.