In my opinion there is no panacea to the problem of foul odours from front load washers.
I have seen posts where it was stated to have been traced to the discharge pipe pushed to far down the drain pipe allowing water to siphon back into the machine. Most machines I know of have a non-return valve to prevent this, and prevent any water in the pipe draining back into the machine. These, even if fitted, may have been defective.
I have seen posts where the smell has been stated to be traced to small items of clothing, baby clothes, sock, ladies flimsies etc. that have got stuck 'somewhere in the works' and are cheerfully rotting away.
Use of excess detergent and/or fabric softener very often coupled with use of other than HOT water. This allows build-ups of these laundry aids to form and then start turning foul. HOT water alone will sometimes get rid of these build-ups. Sometimes the assistance cleaners such as 'Affresh' will help, sometimes not.
In my opinion there are two, normally overlooked, sources of these fouls odours: -
1. The recesses in the hubs of the spiders fitted to many of these machines will retain water even after the fastest spin. This 'water' will contain, inter alia, unused laundry aids (detergent, bleach, fabric softener etc), soil, the products of the interactions between the laundry aids and the soil, the products of the interactions between the laundry aids and the chemicals in the 'tap' water, and 'unused' chemicals in the 'tap' water. When left over time the water will turn foul smelling. A photograph of such a build-up can be seen at: -
http://www.ripoffreport.com/appliances/electrolux-home-prod/electrolux-home-products-n-am-4cd6d.htm
2. The products of corrosion on the spiders retain small quantities of water after the final spin giving the same result as above.
Many posts on many sites claim that the corrosion of the spiders is due to galvanic action. I do not agree, I believe it is primarily chemical corrosion.
Should the corrosion have been galvanic between the stainless steel drum and the aluminium spider the majority of the corrosion would have been at the junction of the two metals i.e. at the ends of the arms. I have seen no photographs of spiders corroded in such a manner, nor read of any similar descriptions.
Aluminium, and its alloys are corroded when immersed in an aqueous solution with a pH value above about 8.0 or below about 4.0 (nitric acid is a well known exception). All detergents have to be above about 8.0 or they would not work. The Material Safety Data Sheets put out by Proctor and Gamble state that the pH for one of the liquid 'Tides' is 8.0 and for one of the 'Tide' powdered detergents as 11.0. Bleach, (sodium hypochlorite) is also very corrosive to aluminium. I should add that for corrosion of the spider to take place these levels are considerably above the levels found in a washing machine during the wash/rinse phases of the cycle.
Sodium carbonate (washing soda) and sodium percarbonate found in some laundry aids (Affresh and Oxi-Clean [powder]) are also corrosive to aluminium and its alloys, as is borax, provided the required concentrations are reached.
I believe the mechanics of the corrosion are as follows.
Even after the fastest spin small quantities of water will remain on the shaft and towards the centre of the spider. Any recesses in the spider close to the centre will aggravate this situation. This water will contain 'contaminants' as detailed above. Should sufficient of these 'contaminants' be present the pH of the mixture can, as evaporation takes place, rise to a level where corrosion will take place.
Corroded spiders can be seen at: -
http://fixitnow.com/wp/2009/10/28/front-loading-washer-corrosion-contagion-a-menagerie-of-metallic-misery/
http://softsolder.wordpress.com/2010/07/15/sears-kenmore-he3-washer-drum-the-rot/
and for a LG spider
http://www.viewpoints.com/LG-TROMM-Front-Load-Washers-review-33dc10
For information on galvanic corrosion there is a very good paper at: -
http://www.powershow.com/view/11752f-MTYyM/UN1001_REACTOR_CHEMISTRY_AND_CORROSION_Section_4_Galvanic_Corrosion_powerpoint_ppt_presentation
For information on chemical corrosion of aluminium (or 'micro galvanic corrosion as the author calls it, I grew up calling it 'pitting corrosion) there is an informative paper at: -http://www.sintef.no/static/mt/norlight/seminars/norlight2003/Postere/Gaute%20Svenningsen.pdf
The only front load washers readily available in North America that I am aware of that do not have recesses close to the centre are Miele and Speed Queen. However there are numerous complaints on the internet about foul odours from these machines, in their favour is the fact that spider failures are virtually impossible to find.
There are many posts on the internet containing complaints about failed bearings in these machines, with some makers' efforts appearing more frequently than others. Undoubtedly the percentage of units sold, in the overall marketplace, by a particular manufacturer will have some influence in this regard.
SKF put out a useful booklet on the subject. This can be viewed at: -
http://www.kamandirect.com/resources/2010/downloads/SKF_bearing_failureandcauses.pdf
I will reference this document several times during this discussion.
The first cause could be a defective bearing received from the manufacturer. Very rare nowadays but it can still occur.
Next the bearing could have 'just worn out'; they do not have an infinite life in spite of what some people think, and SKF do discuss this in the above booklet.
In the case of front load washer bearings unfortunately most of the failed bearings have, in my opinion, so much damage, both mechanical and corrosion, that it is impossible to determine the cause, as per SKF, or even which failed first the bearings or the seal.
Lack of lubrication, again possible, and again, discussed by SKF. Remember there are no facilities provided to introduce more lubrication to these bearings. I do not believe that on its own it is a likely cause. Similar bearings run in some applications much longer without renewing or replenishing the lubricant.
Incorrect grade of bearing used? I do not believe so; remember the 'grade' of a bearing only refers to the dimensional limits the bearing is manufactured to not its suitability for the environment it is operating in.
Brinelling or 'false brinelling' as SKF call it (page 12 of the booklet). I believe highly possible, I would however expect it to occur within the first two to three years of the life of the machine. The bearings removed from two machines I have worked on were marked 'China', additionally many posters on the internet have made a similar observation. This means that in all likelihood these bearings were transported by sea, air cargo is very expensive by comparison, and as SKF note ships auxiliary machinery, is highly susceptible to this type of damage. What about boxes of bearings being transported, in my view they are just as susceptible to brinelling. I further understand that it is now being encountered in the wheel bearings of vehicles manufactured overseas.
Damaged during fitting, again discussed by SKF. I believe possible but not very likely. My reasoning being that should there be a general fault in the assembly process there would be many more failures than there actually are.
I now come to two reasons that I do not believe were adequately addressed during the design and development phases of these machines.
First the material and geometric design of they spider: These spiders are die cast from aluminium alloys. Aluminium and its alloys can be corroded by most laundry aids should the required concentrations be reached. For how I reason this please see above.
The product of this corrosion is aluminium oxide (Al2O3), the same material that provides the 'grit' in sand-paper. Aluminium oxide has very low solubility in water this means that any products of corrosion not adhering to the parent metal or dissolved into solution will be carried about in the 'water' of the washer making a very effective lapping compound. In my opinion the soft lips of the shaft seal stand very little chance against such an effective abrasive. Many posters on the internet who complain of failed bearings also note the corrosion of the spider, could the two be linked?
Perhaps those who claim the seal always fails first are not so incorrect after all?
Many of these spiders have recesses close to the hub, these, in my opinion, provide excellent pockets for corrosion to occur.
Secondly the adequacy of the bearings for the job they are doing.
I do not believe they are adequate. When we purchased our first front loader (May 2001) I wondered how 'they' had solved the 'bearing problem' with no 'front end' steady bearing. In 2008 when I pulled it apart because of bearing failure I found out, to my mind at least, that 'they' had not.
I have seen a couple of posts where the writers have claimed that the bearings are adequate because they are of the same size as is fitted to some small cars and that the small cars are heavier than a load of laundry, or words to that effect. I will not argue that even a small car is heavier than a 'load' of domestic laundry but the rest of the reasoning I believe is totally flawed.
Under ideal circumstances the load on a bearing, of the type we are considering, would be exactly normal to the axis of rotation and evenly distributed around the outside centre of the outer race. I cannot think of a case where this actually occurs.
In the case of a car wheel, and the washers, there are two bearings, in the case of the car the outer bearing takes most of the load and in the case of the washer the bearing closet to the inner drum takes the greater portion. In actuality they also act as fulcrums.
Now for the car from the centre of the races to the point where the wheel attaches is I would guess about 4 inches maximum. From its point of attachment most of the wheel (unless very wide tyres are used) goes 'back over' the bearing housing. This reduces the cantilever effect to the minimum reasonably possible with modern engineering techniques and capabilities, my perception anyway. For the drum, from the washer featured above, from the centre if the inner bearing to the effective rear of the drum is approximately 3.5 inches, almost the same as my guess for the car. The effective depth of the drum is 11.0 inches: taking the midpoint of the drum as the effective centre of the load (I know it will sometimes be greater sometimes less) this at least doubles the cantilever effect on the bearing and should the centre of the load move closer to the door of the washer it will become worse.
Now the point that I believe has not received sufficient attention. In the case of the car wheel, the wheel is 'balanced', (the little lead weights on the rim). Has anyone ever ridden in a vehicle where the wheels have become 'unbalanced' and noted how much 'rougher' the ride is? This places an excessive load on the bearings. Have the same people noted how little in the way of 'balance weights' are required to correct the situation? Very rarely will the 'load' in the washer be 'balanced' and this 'out of balance' load placed on the bearings, I believe, is quite substantial and sufficient, should it be sustained for any great length of time, to damage the bearings.
Then there is the load placed on the bearings by the gyroscopic effect both in the example of the car and in the washer for both 'balanced' and 'unbalanced' conditions but I think that should be the subject of an epistle on its own.