Well here’s a new one …
Recently I developed a sound under my 1989 XJ40 that almost resembled a motor boat. It only happened around a range 25mph to 35mph. Not very loud but it had a harmonics that I could actual feel in my chest.
First thought was an exhaust issue but when I put it up on a lift it turned out to be a drive shaft problem. Everything nice and smooth except in that 10 mph range and then the front section of the drive shaft started really vibrating. Hmmm. Put in a new center carrier bearing item #3 (which I though strange because the old one was relatively new) and the problem was still there.
So after a process of elimination I determined it had to be coming from the front section of the drive shaft.
After making a few calls around the country I found out that Jaguar had a bit of a problem with that part in the past. As you can see in the diagram there are two tubes making up the forward drive shaft (yellow part in the diagram) and the space between those two tubes is filled with vulcanized rubber… BLIMEY ! While not that common it appears that if’s not that rare for that rubber to break down and allow the inner tube to moving around a bit.
Although I could get my hands on several used shaft, who knows what condition they would be in. So I opted to have that part remade into a solid shaft. Should be ready next week and fingers crossed !
Has anyone else even heard of such a problem?