Wheels off ground = No hand brake

[Tip12345]

Yes 4 we is only 2wd take two wheels off the ground is one front and one back . It's stopped ..unless doff locks of some sort .. the doff drives the wheel with the least resistance.

[10G]

Don't have an LSD, it's open diff with a factory locker fitted.

Think I'll look for that Spanish bloke, Manual!

[garett]

Don't have an LSD, it's open diff with a factory locker fitted.

Think I'll look for that Spanish bloke, Manual!

lock the diff then see if it still happens

[the evil twin]

Don't have an LSD, it's open diff with a factory locker fitted.

Think I'll look for that Spanish bloke, Manual!

Engage the Locker and I reckon you won't still be able to spin the wheels.

An open diff means any two shafts can turn whilst a third is stationary

[10G]

You guys all seem to be talking about the same thing which is great, but I still don't understand how the hand brake works???

Can someone please explain it to me???

Thanks heaps.

[mudski]

You guys all seem to be talking about the same thing which is great, but I still don't understand how the hand brake works???

Can someone please explain it to me???

Thanks heaps.

The wheels need on ground contact for the handbrake to work (for open diffs or rooted LSDs only) because its operating via the tail shaft. Same applies for open diffs if you are in motion and one wheel lifts off the ground. Lock the diff locker in and this doesn't matter.

[GQtdauto]

Looks like someone else just worked out most of our four wheel drives are actually two wheel drives , I felt so cheated !

[10G]

Yeah, nah yeah, I understand all that open diff, power goes to the wheel with least resistance stuff, I'm just trying to work out how the hand brake works and so on.

There's something that hasn't clicked. The brake is applied to the tailshaft. The brake stops the tailshaft spinning, is that correct?. The tailshaft connects to the diff. The diff to the axles & the axles to the wheels. Is that correct?

If that is correct I can undertstand how the hand brake would work. But what is it that disconnects or whatever when the wheels are lifted off the ground??

I didn't think to look and it's gonna be 2 weeks until I can look again, but when I spin the rear wheels in the air, does the tailshaft spin??

Ever had that feeling that you know there's a bit of info you don't know, but you think you should know it and it drives you crazy, that's this.

Is there something in the diff that disengages?? I'm no mechanical wizard as you've probably guessed.

Thanks for any help.

[the evil twin]

With an open diff if one wheel can spin one direction and the other wheel is free to spin the opposite direction the input shaft can potentially remain stationary.

If either wheel has resistance then the Input shaft has to turn as well (if one wheel is held stationary the input shaft and other wheel will spin at the diff ratio).

Sooo... when the handbrake locks the input shaft it will therefore only be effective when the wheels aren't hangin in mid air.

Nothing is mechanicaly disconnected... what is 'disconnected' is the wheels from the ground... 'connect' one wheel to the ground or lock the diff so it can't 'differentiate' any longer and then the brake works as advertised

https://www.google.com.au/imgres?img...GOAjIQ9QEIKzAA

In the image if you turn one light blue shaft, the two orange gears rotate in opposite directions to each other and turn the other light blue shaft the opposite way.
The Crown Wheel the orange gears are attached too doesn't need to move and therefore the dark blue shaft (Input Shaft) doesn't move at all

[10G]

AHHHH. So it's the tailshaft that is locked / braked and not the wheels and it's the tailshaft being held stationary that holds the wheels stationary UNTIL they are lifted off the ground, so the hand brake doesn't act on the wheels at all, just the tailshaft.

Thanks ET, I owe you another beer. Awesome I've learnt something.