Guidance on premature failure of replacement bearings

[ajuniper]

Machine: Bosch WFR3269GB/12

I replaced the bearings and seal a few months ago on this machine and they have failed again (loads of noise and movement in the drum).

Before I put another replacement set in, does anyone here have any suggestion as to what I might have done wrong in fitting them? (for the moment I am assuming that the bearings weren’t faulty).

There are some new rust stains leading away from the bearings, and a little rust on the outside of the inner bearing, but both bearings turn smoothly.

Both the bearings were fitted by using the previous bearings as a drift and there’s no damage to the seals.

The replacement bearings were in a BSH box and purchased from this site.

Before I stripped the replacement set off the machine today I measured the distance between the outer faces of the bearings and it’s just over 1mm longer than the shaft bearing faces, which appears to leave plenty of scope for over tightening the pulley on refitting leading to excessive preload on the bearings. Could this cause the failure? If so, what’s the recommended torque for the pulley bolt?

With the bearings removed, I measured the distance between the inner faces that the bearings sit against, and this confirmed that the bearings had been fully pressed home when fitted.

Does anyone have any words of wisdom on what I might have done wrong?

Do these replacement bearings require greasing when fitting them? All the internet advice I found at the time said not.

Also, could it be that the replacement drive belt – supplied at the same time and apparently 1mm shorter than stock – could have caused the failure due to excessive side loading on the bearings?

TIA
Andy

[iadom]

Re: Guidance on premature failure of replacement bearings

By far the most common cause of premature bearing failure when the drum shaft or drum support spider has not also been replaced is due to damage on the drum shaft itself. If the bearings have been left to long before they were replaced then damage to the part of the drum shaft or collar that seats against the seal is such that a proper seal is not possible.

A picture of the removed drum showing the drum shaft would confirm.

[ajuniper]

Re: Guidance on premature failure of replacement bearings

Hi

Photo is attached.

Neither the original bearings nor this set were seized and came out without problem. The seal and bearing surfaces feel smooth to the touch.

thanks
Andy

[iadom]

Re: Guidance on premature failure of replacement bearings

Not easy to see on the iPad but there does appear to be some small score marks on the sealing collar.

[ajuniper]

Re: Guidance on premature failure of replacement bearings

The marks on the sealing collar rub off with a fingernail. I’ve attached another photo (cropped to avoid hitting the 256k file upload limit).

[iadom]

Re: Guidance on premature failure of replacement bearings

I have seen them much worse but ideally there would be none of the lines on the seal face that you can clearly see in your picture.

Belt tension etc is not a cause of bearingS failing IMHO.

[ajuniper]

Re: Guidance on premature failure of replacement bearings

The old seal hadn’t leaked – there were no traces of rust when originally stripped – so I think that the surface should still be capable of making a seal.

Some questions:

• I notice that there are two pairs of tramlines on the sealing ring, could it be that the replacement seal was sat at a different position to the original and was thus less effective for some reason? Should the seal be pressed in all the way down to the bearing or only to some other depth?[/*:m:195vnoh9]
• what is the recommended torque for tightening the pulley bolt? This applies a preload to the bearings – so too tight could presumably cause premature wear on the bearings?[/*:m:195vnoh9]
• should the seal or bearings be greased when assembling?[/*:m:195vnoh9]
• do you sell replacement seals (BSH 00613084) outside of the bearing kit?[/*:m:195vnoh9]

thanks

[iadom]

Re: Guidance on premature failure of replacement bearings

In over 45 years I have never measured the torque when tightening a drum pulley on countless types of washing machines.

Some manufacturers, Zanussi for one sometimes supply a special grease for applying inside the rubber seal, not sure but I think it is sold in the store here.

The seal is usually fitted as far down as you can get it, usually tight up to the bearing. You would have to ask re the seal alone.

[Martin]

Re: Guidance on premature failure of replacement bearings

A liberal dosage of hi speed grease wouldn’t go amiss especially between the water seal and front bearing. As my colleague commented the drum shaft and collar look in good shape.

For the bearings to fail so soon could possibly be attributed to an imbalance in the actual drum. Corrosion build-up within the 3 arms no matter how seemingly minor it appears can cause the drum to be fractionally out of balance putting greater strain on the bearings during high speeds. So a good clean up and close inspection of that support is advisable.

[1totalshambles]

Re: Guidance on premature failure of replacement bearings

Best grease to use is white marine bearing propellor shaft grease which is what I use. The drum shaft looks fine via picture. Points to look out for one of which is sureal: 1) that there are no hair line cracks in the rear plastic half tank around the bearing tube and that the bearing tub has no hair line cracks both unlikely, 2) that the oil seal is the correct one, 3) I can tell from the picture you did not thrash the failing bearings into shrapnel mode so good on you, but I have come across the hub- the bit you mention with the small wear grooves, which is normal- where h2o gets under between the hub and the sharf and I have come across where the hub is warped from manufacture causing water entering between it and the seal running grooves, imagine a buckled bicycle wheel. It should not be the actual bearings that fail it is water getting in to them making them fail. Check as mentioned all 3 spider arms for fracture which is not likely at that age.

[kaibart]

Re: Guidance on premature failure of replacement bearings

No one has mention that the bearing housing where the bearings sit could be shot this is a possibility where the bearings are knocked in could be a lose fit so could require a new rear half where the bearings are press in ready.

[Author]

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