Thread: Viscous Coupling working?

I'm not sure that this is the best way, but it will work:

One a level/smooth surface, lift up one wheel using a trolley jack (making sure the jack is lined up with the car).

Try to move the car (drive away), just make sure you do this very slowly.
If the car wants to move, then your viscous is working. If the lifted wheel just spins happily away & the car doesn't move, then the viscous isn't working.

Originally Posted by Scouse

I'm not sure that this is the best way, but it will work:

One a level/smooth surface, lift up one wheel using a trolley jack (making sure the jack is lined up with the car).

Try to move the car (drive away), just make sure you do this very slowly.
If the car wants to move, then your viscous is working. If the lifted wheel just spins happily away & the car doesn't move, then the viscous isn't working.

The efficiency of the coupling is directly proportional to the size of the hole in the side of the house!

Trev.

Just what are the legalities of proceeding on the Queen's Highway with 3 x normal road wheels & 1 x Trolley Jack, directional control & speed notwithstanding.

I believe the common failure with the viscous couplings is seizing, rather than not locking. Jack one wheel up in the aforementioned manner and try to turn the lifted wheel. You should be able to turn it with some resistance. If you can't turn it, the coupling is seized.

Originally Posted by BigJon

I believe the common failure with the viscous couplings is seizing, rather than not locking. Jack one wheel up in the aforementioned manner and try to turn the lifted wheel. You should be able to turn it with some resistance. If you can't turn it, the coupling is seized.

Dumbass Q, but does this apply to defenders? Mine is pretty ****e offroad with an unweighted wheel. When I jack it up to change tyres, the rear locks (assuming we are only talking rears).... or my handbrake may have been on ....
Assuming it is siezed, is it an easy home fix (for a newby) or a major job?

Defenders have a centre diff lock, rather than a viscous coupling. Diff lock is engaged by pushing the transfer lever (short one) over to the left (passenger) side of the vehicle. Must only be used in low traction conditions.

Lift a rear wheel of the ground and testing is the standard way of testing a Freelander VC - however people who haven't actually done it say you can move the wheel by hand - not so. I need to use a 2' breaker bar on the hub nut and apply steady pressure and the wheel will slowly turn - if you try and jerk it it will not move. There is no way the wheel can be turned by hand.

I assume a RR is similar.

I have contacted the stealer and GKN (the makers) about a more technical way of testing, such as the torque setting range for a serviceable VC to move but it seems there are none - well none that they are releasing.

I don't understand why these cannot be made a serviceable item and be able to change the fluid at regular intervals. When I have time I am going to pull my seized one apart to check this very point out.

Gazzz

Originally Posted by BigJon

Defenders have a centre diff lock, rather than a viscous coupling. Diff lock is engaged by pushing the transfer lever (short one) over to the left (passenger) side of the vehicle. Must only be used in low traction conditions.

Cool, I get the centre diff thing, I just wasn't sure if the VC was sort of like LSD on the rear....like I said, I'm a bit of a dumb ass
Thanks BigJohn