Intermittent noise GU Patrol

Can you give more details? Is it coming from under the car? front or rear? engine area?Does the vary with car speed or engine revs? ... could be anything at this stage... take each wheel off and check things like the hubs and bearings, check the brake calipers and pads(broken retaining clip on pad gave me a similiar noise once) Sounds like the noise is coming from a rotating part so give the vehicle a good going over, other things that come to mind that have given me "noises" over the years are: Aircon clutch/bearing, stuff caught in radiator or thermo fan, broken radiator fan blade, loose brake line bracket hitting back of wheel.

Are there any other symtoms? ie vibrations in the steering at the same time?

Had a very similar sound on my fairlane , every time I lifted the bonnet and got me torch out , !!! the noise went. Sounded very much like the fan flicking somthing, only ever happened on start up and maybe for up to ten seconds after, it didnt happen often, Have a look at anything that the fan could possibly come in contact with. I Finally fixed the problem by trading up to a 3l td Patrol, now it sounds like Ive got a chaff cutter caught under the bonnet .Things dont happen as smooth or as fast these days but Ill survive.

Pete, I had something similar happen to my GQ and it was the front hubs with one side trying but failing to engage (theses are auto hubs like your GU)
I got out the wheel spanner and locked the hubs. It's OK to do this, just don't drive in 4wd on firm surfaces. I asked my mechanic to check the front hubs, he pulled them apart serviced them and I had no problems after that.
Regards Andrew.

Pete, I have heard of GU's sometimes having problems where the oil viscosity in the transfer case is too high particularly early in the morning and the transfer case will try to direct partial drive to the hubs.
The solution I have heard for some with this problem is to change to a fully synthetic oil in the transfer case.
Is your problem usually occuring early in the morning when especially cold? or. Does it occur even when hot?
Regards Andrew.

Make sure you use ATF in the transfer case for GQs GUs with auto hubs...

Will

Guys!

BEFORE you go out and replace the oil, try and fix where the problem is coming from!

In my GU, I run the standard oil and don't have any problems. Try locking your hubs to Manual and driving around in 2wd. If there is a slight power-leak, from a sticking main-gear syncro in the transfer case, then it will only leak just enough power out of the box to try and drive the front shaft. More importantly, you won't get the hubs trying to engage all the time.