her is one for you i have had this with customer before where the wheel bearing has gone on the trailer or caravan and ossolatig though the chassis and through to the the tow bar bringing the noise to the car,the other one i have encounted is where the steel of the box section of the towbar has been cut at an angle and was acting like a read in a musical instoment, this was stopped by putting tape over the box section
Thanks, well, it's a sort of plastic ring thing which holds the oil in the differential (or whatever, our neighbour diagnosed it), ordered and hoefully will arrive today and he will fit it.
How would an oil leak make the diff noisy? Surely the noise would be coming from the centre line of the vehicle if it was the diff. I'd suspect a wheel bearing or perhaps something got into the brakes like a small stone. It'll be interesting to see if the new gasket stops the noise.
The oil leak would make the diff noisy if the level got too low I've had it happen & it was hard to distinguish where the noise was coming from apart it was coming from the rear. In my experience wheel bearings tend to rumble when you get to a certain speed & carry on regardless & don't disappear when the vehicle warms up.
Lack of oil can damage your differential as there is a lack of lubricant, any diff bearing noise can be transmitted and sound from another point, rubber seals can leak as they get older and agin sod's law does exist!
Diff noise usually starts of as a high whine and progresses to a loud deep growl before failure and lose of drive.
If they jack-up one wheel at a time and rotate the wheel any roughness in the wheel bearing should be felt.
What type of vehicle is it and front or rear drive.