toyota full time 4x4

[ejazmalik]

I have toyota Granvia 3.4 v6 2001. I installed locking hubs on the front wheels. When i turn these locking hubs to free then there's a screeching sound coming from the Viscos coupling between the front and rear drive shafts. Is there any way to fix this.

[Snow and Rocks]

If i follow you correctly then the viscous coupling will be under a lot of stress trying to stop all the power from just going to the front driveshaft which now isn't connected to anything.

I'm assuming you don't have a manual locker on the centre diff like a Land Cruiser? I wouldn't even attempt to drive it with the hubs unlocked unless you find a way to lock the centre diff - you'll overheat the VC in no time.

[Smint]

Lockable hubs are usually used on vehicles with selectable 4WD, ie most pick ups where normal drive is to the rear wheels only.
To get drive to the front wheels one engages the centre diff lock.

I suspect your Granvia is designed as a full time AWD vehicle (may or may not have the facility to lock the centre diff) and drive will be sent to the front wheels continually.

I agree with the other poster, the system is protesting because it's trying to compensate for the front wheels 'spinning' all the time as if the front axle is stuck in mud.