Q.
There’s a whining noise coming from the transmission on my Defender. It seems to be coming from the gearbox/transfer box area rather than a diff.
The whining noise increases as speeds rise; it’s getting quite loud at 50mph and louder still at 60mph. It’s the same whether in fourth or fifth. It’s noisier under load and eases off if I back off the throttle.
I had a replacement gearbox fitted a year ago, so that should be okay – but you never know.
David Preston, Cirencester, Gloucestershire
A.
If the whine is definitely from the transmission (and not from the axles), it’s possibly wear of the front or rear output bearing on the transfer box. Otherwise, it’s the final drive bearings that are to blame.
It may be possible to identify the source by removing each prop in turn and driving a short distance with diff lock engaged. A garage using a listening device while the vehicle is running with wheels free on a lift may be able to identify the problem, though it can’t be tested under load in this way.