Hello group, I have a Jaguar XKR Silverstone edition, with 115,000 miles on it, and I'm just noticed a whining noise in the rear of the car, to me it sounds like either wheel bearings or the rear differential. The sound is like waa, waa waa waa. It is less pronounced while under load when accelerating, more pronounced when gliding in gear, and even more pronounced when gliding in neutral. Any thoughts on what that might be?

 

check your differential pinion preload. You may well find movement simply by grasping tailshaft to diff flange universal joint.

 

If the sound continues when the car is coasting in neutral then it sounds more likely to be a wheel bearing but it's easy to check both the wheel bearings and the differential by jacking each wheel off the ground and checking.

Richard

 

Does it sound like this?

This is a bad rear bearing, and after removal, it was determined that the real culprit was a bad hub which caused the bearing to fail.

Hope this helps

 

So, a follow up to my issues, my mechanic says that it is a left wheel bearing, a pinion bearing, AND.....wait for it.....my rear differential! This all adds up to about $4000USD, and that is getting a used rear diff. with 85k miles. I bought the car this summer with 115k miles on it, might have driven it 500 miles since, and I heard nothing when I bought it, much less my other Jag mechanic did not hear anything either. I suspect the rear diff. cannot be rebuilt due to finding parts? Any thoughts on that? Thanks in advance.

 

Price seems way too high, plenty of diffs or even complete rear end assemblies out there for much less. Change over the whole thing inside a day.

 

This is why most of these cars will end up in the scrapyard or in DIY enthusiast garages.

You are at the mercy of repair shops if you cannot perform all or most of the repairs yourself.

Maybe call GARAGE SQUAD like people do on TV? (Motortrend TV https://garagesquad.tv/)

 

I see diff bearing rebuild kits for about $150 on the web. So, parts do exist and they can be rebuilt. You may need some special tools to set pinion bearing preload, not sure because I've never rebuilt one of these.

 

Before you start tearing the rear driveline apart I would confirm what needs to be replaced.

I really recommend getting a set of chassis ears, Steelman Wireless Chassis Ears are the best thing since sliced bread and have saved me countless hours diagnosing chassis and bearing noises. These are a really good investment and you will need these again in future.

With a set of Steelmans you can just clip them onto the diff and rear left/right bearing housing. Drive the car and listen using the wireless control unit. If it is the diff, you will even be able to determine if it's internal diff vs diff output bearings - and allow you to make an informed decision on your repair strategy.

If your mechanic didn't use something like Steelmans to diagnose the problem I would doubt the accuracy of his problem determination.

 

When I worked at the dealer the guy next to me had a set of WIRED chassis ears.(this a few decades ago)

I agree that you can drive around with a 'listener' to switch from each microphone to determine the location of the 'noise'.