XJR Wheel Bearings
Discussion
Hi,
I would appreciate help with this. I have a 2000 model year XJR
with 60,000 miles on it. Recently it has developed a very quite
droning noise between 35- 50 mph which I think is probably a wheel bearing but I can't
place it exactly. There's no obvious play or binding in any wheel
but it did develop just after I replaced the front tyres. I have
tried rotating them front to rear but it has made no difference. It
stays the same with the car rolling and in neutral so it's not
engine related.
Anyone have any experience of this, including diagnosing and
replacing front or rear bearings.
I would appreciate help with this. I have a 2000 model year XJR
with 60,000 miles on it. Recently it has developed a very quite
droning noise between 35- 50 mph which I think is probably a wheel bearing but I can't
place it exactly. There's no obvious play or binding in any wheel
but it did develop just after I replaced the front tyres. I have
tried rotating them front to rear but it has made no difference. It
stays the same with the car rolling and in neutral so it's not
engine related.
Anyone have any experience of this, including diagnosing and
replacing front or rear bearings.
My XJ suffers from a very similar problem - almost like the engine is labouring and yes it does sound like a wheel bearing just starting to go but you can turn it on and off with the throttle.
You can feel a faint vibration through the driver's floorpan coincidental with the noise.
Does it get worse if you climb a hill / have a heavy load on or run on the comfort tyre pressure settings? All of which make the engine work a bit harder especially at the low revs you'll get when driving at 35 - 50MPH in 5th. I can get round it by going into sport mode which holds off the up changes, but there's still a bit of a hummy drone at about 50MPH when it goes into 5th.
Intrestingly there's no evidence of it at all when the engine is cold and it almost fades away when the engine is really hot after several hours driving. Atmospheric conditions seem to make a difference too.
I have a few suspects. It could be:
Tyre resonance interacting with a driveline vibration period.
Worn wheel bearing - the 308 has straight roller bearings which will still feel tight with some wear and don't usually show the classic loud/quiet effect when cornering.
Jurid couplings on the prop may have aged and gone hard.
Airflow meter drifted out of spec causing miss fuelling.
Software problem with engine mapping.
Torque converter vibration.
Exhaust resonance.
The problem is diagnosis. Just throwing parts at it to see what happens is way too expensive to contemplate but once you really know what's wrong fixing it is easy. I've decided to wait until it either gets worse or it gets on my nerves enough to take it to my local indy for a session on the WDS and a second opinion.
You can feel a faint vibration through the driver's floorpan coincidental with the noise.
Does it get worse if you climb a hill / have a heavy load on or run on the comfort tyre pressure settings? All of which make the engine work a bit harder especially at the low revs you'll get when driving at 35 - 50MPH in 5th. I can get round it by going into sport mode which holds off the up changes, but there's still a bit of a hummy drone at about 50MPH when it goes into 5th.
Intrestingly there's no evidence of it at all when the engine is cold and it almost fades away when the engine is really hot after several hours driving. Atmospheric conditions seem to make a difference too.
I have a few suspects. It could be:
Tyre resonance interacting with a driveline vibration period.
Worn wheel bearing - the 308 has straight roller bearings which will still feel tight with some wear and don't usually show the classic loud/quiet effect when cornering.
Jurid couplings on the prop may have aged and gone hard.
Airflow meter drifted out of spec causing miss fuelling.
Software problem with engine mapping.
Torque converter vibration.
Exhaust resonance.
The problem is diagnosis. Just throwing parts at it to see what happens is way too expensive to contemplate but once you really know what's wrong fixing it is easy. I've decided to wait until it either gets worse or it gets on my nerves enough to take it to my local indy for a session on the WDS and a second opinion.
Edited by Jaguar steve on Tuesday 7th October 09:00
Thanks for the input guys. Groomi you mentioned the Diff which has been worrying me so I think I will try an oil change and see if that makes a difference, it's the easiest thing to start with. Jaguar Steve for what it's worth I think your problems in the drive line, I would suspect prop shaft center bearing if you can actually feel the vibration. My noise is completely speed dependant and there is no vibration. I've bought a one month sub to Jaguars workshop manual and apart from the diff oil none of this is an easy diy proposition. Give me back my old series 3 with grease nipples all over the suspension I say.
If I ever get to the bottom of it I will let you know
If I ever get to the bottom of it I will let you know
Yep, prop centre bearing is another candidate. Problem is the vibration is so slight it's easily lost in general road noise and surface roughness. You need a really smooth road and carefull attention before you feel it.
I'm going to have a think about this - my view is once you sart spending time and money chasing very minor problems it's a bit like stepping off a cliff - there's no way back.
I have some 16" diameter wheels and will get rid of the 17" Celtics currently fitted when I finally decide what tyres to buy - which should go some way toward reducing road noise and improve the ride too, and need new shocks on the rear as well. I'll probrably wait until that's been done to see what happens. If it is tyre resonance than problem solved.
On the other hand there's lots of low mileage X350s coming on the market at bargain prices....
I'm going to have a think about this - my view is once you sart spending time and money chasing very minor problems it's a bit like stepping off a cliff - there's no way back.
I have some 16" diameter wheels and will get rid of the 17" Celtics currently fitted when I finally decide what tyres to buy - which should go some way toward reducing road noise and improve the ride too, and need new shocks on the rear as well. I'll probrably wait until that's been done to see what happens. If it is tyre resonance than problem solved.
On the other hand there's lots of low mileage X350s coming on the market at bargain prices....Just diagnosed as nearside front wheel bearing by local Jaguar Independent. They will replace it in a week or so. If they are as good as they seem to be I will post details here.
My random thoughts on this at present are suprise that this has happened at 58k and also, if you decide to grease the Universal joints on the driveshafts to eliminate them as a source of noise just remember, firstly that you can do it, they have grease nipples and secondly, they are on both ends of the drive shafts. I forgot and only did the inners, suddenly noticing the outers when hunting about trying to change the diff oil a week later. How embarrasing
My random thoughts on this at present are suprise that this has happened at 58k and also, if you decide to grease the Universal joints on the driveshafts to eliminate them as a source of noise just remember, firstly that you can do it, they have grease nipples and secondly, they are on both ends of the drive shafts. I forgot and only did the inners, suddenly noticing the outers when hunting about trying to change the diff oil a week later. How embarrasing
Now fixed and silence has returned. Lovely.
Looking at the bearing after it came out was interesting. It is surisingly big, almost like a light commercial and it didn't look visibly worn but was very dry with no sign of grease at all. The problem seemed to be lack of lubrication rather than wear alone and I can't help thinking that this a is a design flaw on these cars, a grease nipple would go a long way to stopping a problem like this developing in the first place. One little shot from a grease gun would have shut this bearing up.
Anyway, job done I'm a happy man again.
For the record the Jag Indy that did this were very good, they took their time and diagnosed it accurately after some effort putting it up on a lift and spinning the bearing with a stethescope on it. Reasonably priced as well, I was impressed.
They are very close to the M25, junction 25 with the A10 so useful for anyone in London or South east.
Details are:
Classic Engineering
Unit 4
Brook Road
EN8 7NP
Phone 01992 788967
Looking at the bearing after it came out was interesting. It is surisingly big, almost like a light commercial and it didn't look visibly worn but was very dry with no sign of grease at all. The problem seemed to be lack of lubrication rather than wear alone and I can't help thinking that this a is a design flaw on these cars, a grease nipple would go a long way to stopping a problem like this developing in the first place. One little shot from a grease gun would have shut this bearing up.
Anyway, job done I'm a happy man again.
For the record the Jag Indy that did this were very good, they took their time and diagnosed it accurately after some effort putting it up on a lift and spinning the bearing with a stethescope on it. Reasonably priced as well, I was impressed.
They are very close to the M25, junction 25 with the A10 so useful for anyone in London or South east.
Details are:
Classic Engineering
Unit 4
Brook Road
EN8 7NP
Phone 01992 788967
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