P38A Viscous coupling

Evening,
Today I jacked one front wheel off the ground, fitted a fuse to put it into transfer neutral, and then turned the wheel by hand in order to check the operation of the viscous coupling.

Now the wheel turned relatively easy and the front prop turned too, is this an indication of a failed coupler

No, it's the sign of a working coupling. It all depends on "relatively" though.
Here's the definitive Ashcrofts test:
1) Secure the output shaft ...
2) Apply a clockwise torque of 27 Nm to the (front propshaft) output flange nut. If no resistance to turn is felt, unit requires replacing.
3) If resistance to turn is felt, apply a clockwise torque of 20Nm to the (front propshaft) output flange nut for 1 minute, this should result in a rotation of approximately 25 deg - 30 deg. If no rotation or a greater force is required, unit requires replacing.

Oh OK it's just that I thought you should have some resistance to turning the front wheel

To do the test jack one front wheel hand brake on and turn wheel with socket on wheel nut is should turn wheel with a fair bit of effort
no fuse in for transfer neutral.

No fuse in transfer neutral?

Yep no fuse.

The reason I am quirying it, is last week I was pulling cars out of a snowy field and the one front wheel span a few times, when I thought as a permanent 4x4 you shouldn't get any wheels spining?

range rovers are permanent 4x4 but they also have open diffs, unless you have lockers fitted or lsd`s they will spin wheels.

Normal behaviour, even for a 4wd. That's why they have traction control

Oh OK well that's great news thanx for your help guys.

Not all have traction control, early did not then they had two wheel control and the later one had four wheel, works with the ABS

You can hear the abs when it is controling the spin. Sounds like a spring boinging behind the dash board.
We'll, I hope that's right!!! Or I've new problems to deal with

Mark Piercy said:

You can hear the abs when it is controling the spin. Sounds like a spring boinging behind the dash board.
We'll, I hope that's right!!! Or I've new problems to deal with

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I'm glad about that because mine makes that noise and I was worried it was something breaking. It's a horrible noise, especially when you're not expecting it!

scottdej said:

No fuse in transfer neutral?

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No fuse but you will need the gearbox in neutral, if you follow me.