Bosch WAT28460GB/11 clanking noise

[Kevin27]

A clanking noise is produced when spinning the drum by hand and at the start of a wash cycle. There is also a noise, presumably from the same source, under the slapping of the washing during a wash cycle. There is no undue noise when spinning and there does not appear to be any play in the bearing. The machine is 7 years old. Any ideas? Thanks.

[Whitegoodshelp (Andy)]

That’s sounds nasty. The first thing you need to do is take the belt off and make sure the noise is coming from the drum and not the motor.
 

It may sound unnecessary but I know of two experienced engineers who spun a drum and misdiagnosed it as drum bearings. In one case it turned out to be motor bearings in the other case it was a mangled drive belt. 

It does sound like something wrong with or caught in the drum though. 

 

[Kevin27]

Thanks for the advice Andy. I won't have time to get to the belt until next weekend.

[Whitegoodshelp (Andy)]

Hi Kevin. Also try to read the first 3 articles here Noisy washing machine

[Kevin27]

Hi Andy,
None of the articles seemed to explain my problem.

Having removed the back panel, with the belt still on, the clanking noise no longer occurs when the inside of the drum is spun by hand.
The outer tub may be moved backwards and forwards against the force of the mounting springs, but there is no witness mark on the inside of the back panel to suggest that the drive pulley has been making contact.
On spinning the drive pulley with the belt on, the motion is braked after one or two seconds, with some associated noise (see video clip). I presume that braking is via mechanical, rather than electronic means as the machine is unplugged.
On spinning the pulley with the belt off, the hollow pulley rings like a bell as my hand comes away, then it continues to rotate without braking, with a very faint clicking sound presumably from the bearings (hear audio clip).
This suggests to me that braking is achieved within the motor. I know nothing about the brake and what triggers its operation, but wonder whether the original clanking noise might indicate a problem with it (although the drum slows normally at the end of a spin cycle).

Thanks for your thoughts.

[Whitegoodshelp (Andy)]

Hi. If you are sure the noise isn't being made by the movement of the outer drum shaking something that's loose, it has to be the motor. Maybe it has some sort of centrifugal part, but that's unusual. What does the motor sound like on spin with the drive belt disconnected? Also, I presume this is a totally new noise, and it never used to do it?

[Kevin27]

The machine is 7 years old and had only been making the noise for a few weeks. The motor sounds fine on spin with the belt off. I have jiggled and wobbled everything I can reach inside the casing without eliciting any unexpected noise. With the back panel replaced, I have spun the drum by hand, both empty and with a full load of washing. I have washed two loads. The clanking noise has gone! I am completely mystified.

Thanks again for your help.

[Whitegoodshelp (Andy)]

Thanks for the update Kevin. The mystery deepens. Please let us know if there are any developments.