rear wheel bearing?

PostPost by: iain.hamlton » Fri Jun 02, 2006 8:57 pm

Last weekend, I noticed a high pitch squeak from the back of the car at slow speeds. I am now convinced it is coming from the left hand rear hub or wheel bearing. What i should to is replace the bearings to be on the safe side, but that sounds a horrible job. Is bearing failure immenent? - At the moment, there is no slop, lift, endfloat or roughness. When should I set into to replacing the rear bearings?

suggestions welcome.

best regards, iain
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PostPost by: types26/36 » Fri Jun 02, 2006 9:18 pm

iain.hamlton wrote:Last weekend, I noticed a high pitch squeak from the back of the car at slow speeds. I am now convinced it is coming from the left hand rear hub or wheel bearing. iain


Bearings dont usually make a "squeak"......more of a rumble or grinding noise so check other options first........could it be hand brake pads touching? anything related to the disc's?
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PostPost by: rgh0 » Sat Jun 03, 2006 1:22 am

Iain

Sometimes a stone can jam in the brake caliper and then rub on the disk or jam between the hub and the shaft flanges and cause a sweak like you describe. The seals in the wheel bearings can cause also a squeak if damaged or if the bearing is starting to dry out sometimes also.

Does the squeak happen only when the car rolls slowly with the weight on the wheel or does it happen with the wheel jacked up and you turn the wheel slowly by hand ?

If it happens with the wheel jacked up you should be able to positively locate where it is coming from and see if there is anything causing it. If it is still coming from inside the hub and no obvious external cause then I would try spraying a little WD40 in either end of the hub at the bearing seals. If it goes away fine if not then its probably inside the bearings and just to be on the safe side side I would replace them.


If it goes away when you take the weight off the wheel then again if you can see no abvious cause like something rubbing or jamming it would appear most likely to be inside the bearings and would replace the bearings to be on the safe side.

The bearings inside the hub will normally display a rumbling and roughness as they turn prior to total failure. A squeak can develop before this when a ball starts skidding on its track or the cage due to the lubrication drying out or damage to a ball or race causing a small flat spot. This skidding rapidly increases the damage until you get the rumbling and slop in the bearing.



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PostPost by: iain.hamlton » Sat Jun 03, 2006 4:50 am

Thanks, Rohan.

Great minds think alike! I did exactly as you suggest. I took off the wheel off (supporting the hub-carrier to keep the rotoflex angles sensible). The squeak is still there when you turn the hub by hand. I moved the pads away, and the squeak presists. Next I put a little WD40 in the gap between the hub and carrier on the outside, and squeak was gone. I didnot bother checking the inside as the noise had gone.

So I am baffled. The noise is more "braky" than "bearingy", but it is coming from the hub. I particular, it is consistent with a brake that has been wet and has dried out, like landrover drum brakes. The bearing feels smooth. with no play.

I suppose the questions remain:
Is this an early warning of doom?
Will the bearing last a while (say 1500 miles until winter hibernation)?
What is the normal symptom of a dodgy wheel bearing? Something gradual or will I be stuck on the side of the road? Or worse...
Does anyone advocate routine change of rear bearings? At what interval.
How often should you check the bearings for play? I have been doing it evering time I jack up the back of car, which is frequently, for one reason and another.

We will see if the noise comes back as the WD40 dries out.

Many thanks!

best regards, iain
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PostPost by: rgh0 » Sat Jun 03, 2006 7:25 am

Iain

Sounds like it was the outer bearing seal rubbing and squeaking and a bit of WD40 stopped it. They are normally lubricated by the grease from inside the bearing. Could be an early sign of a developing problem with the grease in the bearing drying out or nothing at all to worry about. You should be OK for 1500 miles if the bearing is smooth when turned and no slop in the shaft.

Normally wheel brearings fail progressively and you will hear them start to make a noise and be able to feel the slop and roughness when you jack up the car. The risk of being stranded at the side of the road is low as long as you change them once you detect any real problem.

I dont believe you need to routinely replace Elan rear wheel bearings, they should be good for 50,000 miles at least. I check mine every time I have the wheels are off the ground for any reason just to make sure nothing is starting to develop free play in the bearings or suspension. This is about once a year for the road cars ( and before every race for the Elan).

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PostPost by: 1964 S1 » Sun Jun 04, 2006 4:20 am

I'm with Rohan again on this one. I'd add that, if you're taking an extended highway trip within the 1500 seasonal miles, be careful. The additional heat buildup during long range high speed runs might be enough to burn up a bearing that's starting to go.
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PostPost by: pete.skellon » Wed Jun 07, 2006 9:05 pm

My experience of worn wheel bearings are a graunching rumble, that only very slightly changes when that side is loaded e.g. near side bearings on a right hand bend. My Elan is currently making these sounds and am hoping to do the bearing this weekend.
It's a pig of a job. Make sure you have a good hub puller and preferably the Lotus tool that clamps on the the hub. I use a 5-inch diameter pipe flange bored to fit over the knock-on screw threads. The flange is held in place by spare knock-ons which are drilled to allow the hub puller to bear against the quarter shaft.
When pulling off the hub, tighten the puller as tight as you dare then give it an almighty clout with a large hammer and stand back. In my experience the whole assembly ejects itself from the car by about 12 inches.
Then comes the fun of actually removing the quarter shaft, and removing the bearing from this.
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This job is not for the faint hearted.
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