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Discussion Starter · #1 ·
Having balanced my wheels, I am still getting cabin vibration , especially at 80mph or over. I am assuming the next port of call is checking wheel bearings. The vibration is still present when I depress the clutch, so I guess it points towards the bearings. Car has done 90,000 miles. Any advice would be appreciated. Are wheel bearings costly?
 

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Hi, Jez.

Try checking the tightness on the front hub nuts. You (or your mechanic) need a big torque wrench, as it should be torqued to 280Nm or 207lbft.

The hub nuts (especially the left one, for some reason) can work loose and this allows play in the wheel bearing, which can make "worn wheel bearing" noises.

As far as I'm aware, the wheel bearings on my Aero are original at 170K miles, but I have had this problem with the hub nut.

If you find you need it, a front hub assembly, which incorporates the bearing, can be had for around £65 + VAT.
 

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Discussion Starter · #5 ·
Tyres are very new , the wheel rims are a little skuffed, but seem fine; I am going to get them reconditioned soon.

Have to say that the Saab does seem to be more sensitive to this kind of thing than other cars I have owned.
 

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OK, so I feel like asking a silly question (Whats new say all of you).

Did you get all four wheels balanced. I ask just coz, if you onmlyu had the front two done, this could explain why the vibration is 'in the cabin' as opposed to 'in the steering wheel'. The rear wheels transmit their imbalance through the seat whereas the front wheels send theirs through the steering wheel.
 

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Just a thought as I've had this in the past, but it might be worth getting the wheels ant tyres check balanced at a different tyre place. I've experienced differences between machines, I understand they are supposed to get their machines calibrated every so often, but I bet some don't bother
 

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This has come up before and another thing which can cause vibrations even when the wheels are balanced is when one of the tyres is out of round. Usually noticeable by a slight side to side motion at slow speeds. Worth checking.
 

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BillJ et al,

right handed threaded bolts used on left hand side wheels have a natural tendency to loosen if not tightened sufficiently. It's the anticlockwise rotation that does it! Right handed threads on right hand side wheels will self tighten if loose. Rolls Royce have always used left handed threaded wheel bolts on the left hand side to prevent left hand wheels falling off. I believe Ford have also adopted this philosophy in recent years. I learned all about this the hard way many years ago: I was interrupted whilst putting the wheels back on, forgot to torque the left hand rear wheel properly, and then set off down the motorway. Vibration started and got worse and worse. I stopped and checked but didn't notice anything. I set off and shortly afterwards there was a clunk, and I was overtaken by my rear left wheel. Fortunately, the wheel came to rest on the grass verge, and all four nuts were still in the hubcap. BUT, you try jacking up a Mini that's sitting with its hub on the ground!

You could always use an appropriate grade of Loctite on the drive shaft (hub) nut.
 

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Like JFP, I have had several experiences of balance machines being out of cal.

Go back to original garage and get them to re-check balance. Any imbalance should show unless wheels are put on same machine in exactly the same orientation as when last balanced.

If out of balance, garage should rebalance all 4 wheels. BUT make sure they rotate wheel between 90 and 180 degrees after each balance, and run a respin to check wheel is still balanced. This will verify that the machine is correctly calibrated. If machine is out of cal, you should get a refund for the original balancing fee and go elsewhere!

Some garages only balance alloy wheels on the inside (using stick on weights), so weights do not look unsightly on outside. But this will not correctly balance wheels in some cases, depending on where the imblance exists. In some cases you need weights on the outside of the wheel as well as possibly on the inside.

I had my last set of (4) tyres balanced at least 4 times each due to bad balancing procedure and out of cal machines!!


Wheel bearings give a distinctive noise. Whilst 9000 bearings are 'not' the cheapest, they are very reliable normally and heavy duty. The front kerbside bearing normally goes first as this one suffers most from pot holes, kerbs, etc.
 

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Thanks, Mark.

That's interesting. I first noticed it one day when the car was off the ground at Abbott Racing. While they were looking over other bits of the car (and scrutinizing the competition's products), I grabbed the left front wheel experimentally. Ed Abbott had said during the test drive that it felt as though one of the wheels was "flapping about". He was right, and it was just the left-hand one.

Originally posted by Mark B:
[qb]You could always use an appropriate grade of Loctite on the drive shaft (hub) nut.[/qb][/b]
Ed said they'd seen this problem often (but didn't make any distinction between left and right) and said the usual cure was to apply threadlock and tweak it up with an air gun, which they did. It wasn't long before it was loose again. Even a new nut hasn't cured the problem. I simply check it frequently now.
 

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Discussion Starter · #13 ·
Just came back from another KwikFit. All four wheels were out by quite a way! So, avoid their Obbourne Road, Colchester branch like the plague; they had balanced them twice in the last 6 months. Oh, they checked the hub nuts & they were fine.
 

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Discussion Starter · #14 ·
Went to kwik fit again today & the wheels that had been balanced by another store were proved to be out too! they had just had their machine re-calibrated. So, the sage of the story is; ask when your tyre shops balancing machine was last serviced. I know have much fewer vibrations.
 

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Discussion Starter · #15 ·
& now for the one without loads of spelling mistakes:

Went to Kwik Fit again today & the wheels that had been balanced by another store were proved to be out too! They had just had their machine re-calibrated. So, the saga of the story is; ask when your tyre shops balancing machine was last serviced. I now have much fewer vibrations.
 
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