Diagnosing a noise

[Oriskany]

I haven't had my 55 reg' 3.0 X type Sovereign for long, but it is making a noise and I don't know what it is. It happens a variable short period after setting off and is best described as a "Draying" noise that changes pitch with speed. It continues both on acceleration and overrun. I don't know whether it's the diff, the transfer box or a wheel bearing - any ideas ? Thanks.

[Oriskany]

On 24/01/2017 at 0:12 PM, Oriskany said:

I haven't had my 55 reg' 3.0 X type Sovereign for long, but it is making a noise and I don't know what it is. It happens a variable short period after setting off and is best described as a "Draying" noise that changes pitch with speed. It continues both on acceleration and overrun. I don't know whether it's the diff, the transfer box or a wheel bearing - any ideas ? Thanks.

****Update**** - The noise was due to the transfer box containing nearly no Oil! I got the car up on ramps and prepared the area for the deluge of gunge that I expented by removing the transfer box filler plug - gingerly removed the plug and ...nothing but a mound of magnetically-attached gunge on the plug. I managed to get over 400ml of new Oil in and a test drive revealed that the box is now so much quieter but since matter cannot be created nor destroyed, what happened to the 400ml+ that had "disappeared"? - there are no visible leaks and all looks dry down there.

 

I have owned a few XJ40s, and the Oil in the diff on those used to "disappear" over the years but I assumed it escaped as vapour through the breather valve. This box doesn't have one - does it? Anyway - nice and quiet now.