Jaguar XJ8 (X308) Wheel Bearing Noise
On the X308 a worn front wheel bearing is the usual source of a hum, a grainy feel or a rumble like driving over rumble strips. Each front hub carries one sealed cartridge that can't be adjusted or greased, so any real play means a new bearing. Before you order one, rule out the rear: there, play only at 12 and 6 o'clock points at the drive-shaft joints or the differential.
How bad is it · Garage, carefully
Drive it gently to a garage, but don't put it off
A worn bearing usually gets loud long before it lets go, so a short, slow trip is fine. Grease flung onto the inside of the wheel is the exception — the bearing is running hot and the wheel can seize.
Which one applies to yours depends on your symptoms, your model year and what has already been done to it.
Likely causes, most common first
Read the check cost before the odds: a free check that rules a cause out beats a likely guess that costs money.
Worn front wheel bearing
From 1998 the XJ8 and XJR use one long, sealed twin-row bearing in each front hub, pressed in and held by a circlip. It has no adjustment and no grease point, and it often wears out somewhere between 45,000 and 75,000 miles.
First a faint graininess at low speed or under light braking, easy to blame on tyres. Then a hum, or a rumble felt in the wheel and the seat that can come and go during warm-up. At the very end the wheel flops about when the car is jacked up. It's usually loudest in the bends that load that side.
Jack the front up and rock each wheel at 12 and 6 o'clock; a healthy hub has next to no movement. Early wear hardly shows as play, so a hum that changes as you weave gently on the road counts as much as movement.
Fit a new bearing with a new circlip, never a used bearing. The other side is often not far behind, so check that hub while you're there. Have the alignment checked afterwards.
Stones caught in the tyre tread
A small stone wedged in the tread clicks against the road once a turn, and in a tight bend it sounds very like a failing bearing or a drive joint.
A loud rhythmic noise from one front corner at walking pace in a sharp turn, quiet when you drive straight or turn the other way.
Before anything comes apart, look closely along the whole tread of that tyre, inner edge included.
Pick the stones out and the noise goes with them.
Worn rear hub or hub pivot bearings
The rear hub bearings are set by the big drive-shaft nut, and the hub carrier swings on its own pivot bearings. A dry, overheated bearing squeaks; worn pivots let the whole wheel rock.
A squeak or a turbine-like whirr from one rear corner, and play when you rock the lifted wheel up and down. It can begin as a chirp and turn into a grating noise with real play within a couple of months; on a smooth motorway the first sign may be only a grumble.
Rock the lifted wheel and watch the hub carrier, not just the tyre. At walking pace pull the handbrake on lightly: if the squeak stops, the handbrake is rubbing, not a bearing.
Unlike the front, the rear hub bearings can be adjusted, but only with a new nut and never to zero play when cold. Pivot bearings that have rusted into the hub may have to be cut out. Don't put it off: a rear bearing left too long can take the hub and the brake disc with it.
Rear play from a drive-shaft joint or the differential output bearing
At the back the wheel hangs on the drive shaft, so wear in its universal joints, or in the bearing where the shaft leaves the differential, feels just like a bad wheel bearing.
The lifted rear wheel moves at 12 and 6 o'clock but not at 3 and 9 — a loose hub would rock every way. A whirr, or a clunk over bumps from one rear corner. A growl that comes only when accelerating through a bend one way points the same way.
Rock the rear wheel both ways, then grip the drive shaft and feel for play at each joint and at the differential flange. The joints carry the last grease nipples on the car, and they are often never greased. If an MOT calls rear bearing play, ask for this check first; worn lower trunnions have been taken for bearing play too.
A worn output-shaft bearing can be replaced together with its seal, without a new differential. Don't accept a differential on a guess. Slight play with no noise and a dry seal can be left and watched.
A dragging or loose brake caliper
A sticking piston keeps the pad on the disc and heats that wheel; a loose caliper knocks. Both get blamed on the bearing.
One wheel centre runs much hotter than the other after a drive, the car pulls to one side, or there's a shimmy around 50–55 mph.
After a drive compare the wheel centres by hand or with an infrared thermometer. With the wheel up it should spin freely, and the caliper bolts must be tight.
Clean or rebuild a sticking caliper and tighten a loose one. A dragging piston also distorts the disc, so check that too.
A tyre or wheel out of round
An out-of-round tyre or a poor balance gives a vibration that's easy to take for a bearing, especially one that peaks at a single speed.
Vibration around 50 mph that fades by 60, and no change in the noise when you weave. Or a drone that started the day new tyres went on.
Ask for a road-force balance, then swap front and rear wheels and see whether the vibration moves with them. Ask the fitter not to use an air gun on the alloy wheel nuts. If the noise doesn't change in left and right bends and there's no play, try another set of wheels for a day.
Balance or true the tyres, and replace one that won't run round.
The order to check them in
The point of the order is money: each step either rules a cause out or makes the next one worth doing. Green is free, amber costs a little, red is the one to arrive at last.
Rock each wheel off the ground
Jack one corner at a time and rock the wheel at 12 and 6, then at 3 and 9. At the front, movement in every direction means the bearing; at the rear, movement only at 12 and 6 points at the drive shaft or the differential.
freeWeave gently at steady speed
On a quiet road, sway the car gently left and right. A bearing hum rises and falls as the weight moves on and off that side; tyre noise stays the same.
freeLook and feel after a drive
Look for grease thrown onto the inside of the wheel and compare hub temperatures side to side. Grease on the wheel means a bearing running hot — get it in now; a hot hub without grease points at a dragging caliper.
freeRule out the handbrake at the back
For a rear squeak, pull the handbrake on lightly at walking pace. If the noise stops, the handbrake mechanism is rubbing.
freeOrder the bearing by VIN
Two front bearings were fitted: MJA1830AE up to VIN 853935 and MNC1830AA from VIN 853936, with circlip JCR110765 and spring MJA1845AD on the early type; the later retainer can differ. Check the size before you order, as the two sides of one car have been found different. As a rule of thumb, 1998 cars take the 76 mm bearing and 1999-on cars the 80 mm one.
a bearing and circlipFit it with the right tools
The hub has to come out and the bearing is pressed, so it needs a press. The ABS tone-ring nut behind the bearing takes special tool EA 206-066A or a 2 in 12-point socket; a nut chiselled off can later bring WHEEL SPEED SENSOR FAULT. The lower ball joint is a tight fit in the arm and may have to be cut off, so have a new one ready. A board drilled for the wheel studs will hold the hub while the nut comes off, and a machine shop can do the pressing if you bring the hub.
about 3 hours a side at a garageWhat it usually isn't
Don't spend money here first:
If none of this finds it:
On jagaux.com
- Jaguar XJ8 (X308) ABS LightIf the ABS lamp comes on after a front bearing has been replaced.
- Jaguar XJ8 (X308) Timing Chain Tensioner ProblemsIf the noise follows engine revs rather than road speed, it's in the engine.
- Jaguar VIN decoderConfirm your exact model year, engine and factory options before ordering parts — free.
Ratings, fuse numbers and torque figures vary by model year and market. Read the legend on your own car before pulling anything, and use the figures in the manual for your car, not the ones in a video.
Check your VIN: exactly which car you have and which bulletins apply to it.