Whirlpool duet washer makes banging noise during spin cycle. Removed back cover and found loose pulley. Nut is tightened all the way. Did a washer or bushing disintegrate? Used metal washer for temp fix but nut backs off after a few days and pulley doesn't spin evenly (under visual inspection pulley looks even and balanced).

LOT OF THINGS TO CHECK, THE BELT LOOSE OR WORN, THE CLUTCH, THE TRANNY, THE BEARINGS BOTH TUB SEAL AND BEARING, THE REAR DRUM BEARING, the balance or counter weights.

THE DRIVE PULLEY- If the washer is making a loud noise the drive pulley might be worn out, cracked, loose or bent. Remove the drive pulley and inspect it carefully. If it is damaged or defective replace it.
THE TRANSMISSION, THE MOTOR COUPLER, THE MOTOR DRIVE BEARINGS,
THE DRIVE MOTOR- If the washer is making a loud noise the drive motor bearings may have worn out. Washer motors are normally almost silent when they run. If the motor is run without a belt hooked up to it and it's loud it will have to be replaced.
The drive coupling connects the motor to the transmission and consists of two plastic drive forks with a rubber coupling between them. One of the drive forks is attached to the drive motor shaft and the other is attached to the transmission input shaft. As the motor shaft rotates, the rubber coupling between the drive forks absorbs the torque to prevent the forks from breaking. Normal use will create wear on the coupling and eventually the drive forks may slip and cause a vibrating noise. If the transmission seizes or if the spin basket cannot turn freely, then the coupling may fail and again you may experience a vibrating noise. Most models will require you to remove the cabinet to access the drive coupler. Disconnect power from the appliance before attempting any repairs.

If the washer is making a loud noise the drain pump might be going bad or might have something caught in it. Remove the drain pump from the washer and inspect it carefully. Look for anything that might be caught in it, a piece of wire, plastic, etc. If nothing is wrong with the pump, but it's still noisy it will have to be replaced.

Front load washers often use a self contained electric drain pump and the motor may be worn or damaged and require the complete pump to be replaced. Remove any foreign objects or replace the worn or damaged pump, thencarefully tighten the hose clamps and check for leaks before installing the cabinet or front panel.
All front-load washing machines have shock absorbers that are used to dampen the tub movement in the spin cycle. The shock absorbers or struts are attached to the base frame and to the outer tub and you will need to remove the front panel or the rear panel to access them. When shock absorbers weaken or become damaged, the machine will often make a loud banging sound during the spin cycle and if the symptom is not corrected, can lead to damage of other components. Inspect the shocks for signs of broken attachments, leaked fluids or a weakened dampening action and replace both shocks if worn. Remove power from the appliance before attempting this repair.

Some models of top-load washers use tub dampening straps to cushion the movement of the tub during the spin cycle. There are four straps attached to the top of the tub and to each corner of the cabinet

Also There are four suspension rods that suspend the tub and allow the tub to free float. If the suspension rods are noisy, there will be a squeaking noise during wash. You can fix this by putting bearing (lithium base) grease in the cup that each rod rests in. If it continues to squeal replace all four rods the cups come with the rods, replace them as well.
If your washer has a loud banging noise during spin the balance weight may be loose. This weight is to counter act the weight of the motor so you will find the weight directly behind the motor. Sometimes simply tightening the bolts will fix your issue but if the bolts are stripped out get some bolts slightly longer than the original bolt to allow you to put a locking nut on the bottom side of the mounting plate. If the weight is broken replace it.

Lastly Washer vibration can be caused by a broken counter balance spring. Ur washer may be equipped with one or more counter balance springs which help to absorb the natural movement of the spinning tub. If a counter balance spring fails the tub might lean in one direction more than another and it will shake and cause vibration.

I have a similar model (WTW4850XQ1) that was making a very loud grinding/screeching noise during the agitation and sometimes the spin cycle. I unplugged and turned it on its front to get underneath and exposed the motor/transmission unit. Took the cover off the belt drive assembly and my drive gear was loose. Simple tightening down of the nut was an easy fix for me. But some times those plastic gears between the drive pulley assembly and transmission crack or the teeth wear down (think it's called the CAM). That is a fairly cheap and easy fix as well ($35). Repair Clinic website has free videos on how to diagnose and fix issues and parts as well. Worth a look.

You have the problem. Replace the pulley. Here is the part to order.

Hi,
When my washer did that, I found that the shocks that hold the tub were bad...

Check out this tip I wrote about that...

http://www.fixya.com/support/r3663122-washer_problems_washer_noise_when

heatman101

BEARINGS

If the pulley doesn't fit the shaft anymore, it may have sheared a metal key between the shaft and pulley center. If it did, you may have to replace both the key and pulley. If the key is intact and the set-screw is only loose, just tighten the screw and you're home free. Make sure the belt has not been damaged--replace it if so. The belt should be fairly tight when things are back together.

old duets have nut on rear pulley that becomes loose. remove rear panel and tighten nut. check while spinning by hand if pop is felt. if it rotates smoothly then you may need new shocks on tub

spin basket surport is defective..put unit in spin without clothes do it bang and clang,,sound like train ,or airplane,,if so contact whirlpool your under warrranty for spin basket..onthejob

If the the drum feels loose in any way, there are three possible reasons:
1. The pulley nut has come loose. (easily repairable from the rear)
2. The bearing is bad (part of the rear tub).
3. The spinner has come loose from the basket (what you describe)

In cases 2 and 3, the entire drum/tub assembly will have to be removed, disassembled and repaired/replaced.

Check your owners manual for possible limited warranty. Contact Whirlpool for potential warranty repair concessions for case 3 if not covered under limited warranty.

Regards
reg501..The FixYa Team

The "cleats" inside the wash tub are actually called "fins". If they are loose try tightening them to see if the sound goes away. You should be able to tighten them from inside the wash tub. Some models have mounting screws that are accessible from inside the wash tub. However, if your machine is knocking like you say it is, it could be sign that one or more of the mounting shocks under the wash tub could be bad, the rear tub bearing could be going bad, or the drive pulley could be cracked or warped. Remove the lower kick plate and watch the shocks during the spin cycle. The shocks should vibrate some, but should not be excessive to the point that it causes an unbalanced spin. To check the drive pulley, remove the 3 screws from the washer top in the rear of the machine. The top should slide back some and then lift off. Watch the drive pulley behind the wash tub during the spin to make sure the rotation is smooth and even. Sometimes one of the arms on the pulley can crack or become bent and cause the pulley to wobble. More than likely, though, the drive belt would slip off. I have also seen where the hole in the center of the drive pulley starts to "round out". The hole is not perfectly round and has to flat sides. Sometimes over time the drive shaft will start to slip around the flat sides, causing the pulley to rattle during the spin cycle. If the rear tub bearing is starting to go, the washer will be very noisy during the spin cycle, and you may start to notice some stains on your clothes if the bearing seal has been breached. You can reach inside the wash tub with the unit turned off. With one hand, push up on the wash tub and release. If you can feel the tub moving up and down (even the slightest) this could be a sign that the bearing is worn out. Now this should be a noticeable metal on metal type feel. Not the normal motion of the wash tub moving up and down from the motion of the shocks. The tub bearing is not a cheap (or easy) fix. The entire back section of the rear outer tub shell has to be replaced, because the bearing is molded into the plastic. Check all the easy things first. Let me know if this helps.