BW transfer box noise

[Drakes]

I have a 1993 RRC with the BW transfer box, I know what happens when the viscous coupling unit siezes and you get wind up. The question is does anybody know what are the first signs of the viscous unit starting to fail, the reason for asking is that I have some strange noises occasionally that sound a bit like something rubbing or dragging. I have checked the handbrake is not dragging and wheel bearings are all ok. I am open to any suggestions to as to what the noise may be if it is nothing to do with viscous.

[rocksteady]

I've had two go on me, and there have been no adverse noises at the time. Try the standerd test by jacking one wheel up, you should be able to rotate but with resistance. If not, then it has failed. The drive line on an RRC has an ability to transfer noises across axles,It can be difficult to locate where a specific noise comes from. Have you had a look at your uj's?

[Bille]

I've had one go on my '93, the first indication I had was when in a parking area with a very minimum loose surface when I turned it sounded like something (Cardboard carton??) was dragging under the vehicle, when I looked there was nothing, I then realised it was to do with the transfer box viscous coupling.

I nursed it home and ordered a new one from the UK, cheaper than sourcing local in Perth Western Australia even with freight and delivered in 6 days despite being sent to Denmark (Europe)for 24 hours then back to the Hub in UK then to Perth.

Wasn't a biggie to replace, mate gave me a hand and it took about 1.5 hours I recall.

[Drakes]

I have done the normal checks and all is ok, I was just trying to figure out if the noises were an early warning or something else that was not actually showing in the normal checks

[David Sparkes]

Noise from the BW transfer box is normally the worn chain hitting the case. Often called 'slapping' the case, which might signify the type of noise. Alternatively, or perhaps as a Stage 2 if the first noise is ignored, is a loud BANG as the chain jumps a tooth when the engine is delivering high torque. Accelerating from a start is the obvious occasion, but it can also happen going uphill.

I have no personal experience of either of these situations.

Whether these explanations fit the circumstances and type of noise you get is impossible for me to tell, but you can perhaps bear them in mind when assessing the noise in the future.

ISTR there are articles about DIY change of the chain on the RangeRovers.net site, but I don't know if they are in the main site, or the 38A forum. I know yours isn't a 38A, but the wear and symptoms will be shared, and there are more BW equipped 38As than BW equipped Classics.

HTH