Bosch's General Troubleshooting for a shaking or shuddering WAT28400UC during the spin says the washer drum suspension system shifts during spinning as the speed increases, which may cause a slight shaking of the washer during the spin speed transition; mix small and large laundry items to minimize it, check that the washer is level and all four feet press equally against the floor, and check the transport bolts were removed. Bosch also says the drum should be checked and debris removed after each load, since loose debris and fluffy fabrics can block the drain pump, and it lists a blocked pump as a cause of poor draining.
Differential
Likely causes of “Bosch 300 Series WAT28400 front-load washer makes grinding”, and how to tell them apart
- 1
Transport bolts not removed
What separates it There is violent noise from the first use because the transport bolts were not removed
How to confirm Remove the transport bolts as the installation section shows
- 2
The four feet not pressing equally
What separates it There is rocking and shuddering in the spin because the four feet are not pressing equally
How to confirm Level the washer and lock the feet with the locknuts
- 3
Debris in the pump
What separates it There is rattling while draining because of debris in the pump
How to confirm Clean the drain pump and check the impeller turns freely
- 4
A small load or a load of one size
What separates it There is shaking at the spin speed transition because of a small load or a load of one size
How to confirm Mix small and large items, and run the spin again
Before you touch a setting
Record this first — changing settings destroys the evidence
- What the noise is and when
- Whether the transport bolts were removed
- Whether all four feet press equally
Try in this order
0 of 5 completedCheck the transport bolts
ReversibleCheck the transport bolts, since they must be removed, as shown in the installation section.
Level the washer
ReversiblePress each corner of the top; there should be no wobble; lock the feet with the locknuts without changing their height.
Mix the load
ReversibleMix the load, by washing small and large items together in one load, and then test again to see whether it helped.
Clean the pump
ReversibleClean the pump, by removing debris and checking that the impeller turns freely, and then test again to see whether it helped.
Check the drum
ReversibleCheck the drum, and remove any visible debris after each load, and then test again to see whether it helped.
Model-specific
What is true of this model and not of its siblings
- Levelling in Bosch's words
- Press down on each corner of the washer top to make sure it does not wobble; there should be no give or movement, and all four feet should press equally against the floor, which Bosch says is as important as being level. When it is level and steady, lock the feet by tightening the locknuts against the bottom, holding the foot so the height does not change. To extend a foot, have someone lift the washer slightly and turn the gray plastic foot downward.
- Cleaning the drum
- Metallic debris left in the drum can produce rust spots on it, and Bosch says never to use steel wool to remove them; use a chlorine-free cleansing agent according to its instructions. Small amounts of descaling agent can remove white spots from lime or minerals, but descaling is not necessary if you use correct amounts of detergent, and the acids in descalers can attack parts and discolor laundry.
- Parts for this problem on the WAT28400 (RepairClinic, 2026-09-20)
- shock absorber, part number 00742719, at $60.40; drain pump, part number 00145753, at $155.35; motor, part number 00145752, at $100.78; the 00439490 drive belt is a genuine bosch oem r, part number 00439490, at $44.20.
- Other models this page answers
- These steps also fit the 300 Series WGA12400UC washer, 800 Series WAW285H2UC washer, 800 Series WGB24600UC washer.
Stop boundary
When this stops being a self-service repair
- !If the noise continues after levelling and cleaning the pump, call Bosch customer service
- !If the drum scrapes the housing, stop using the washer
Evidence ledger
Sources behind this answer
Bosch's own US owner-support pages for washer error codes and self-help.
Parts and list prices as shown on RepairClinic's parts search for this model number on 2026-09-20.
Exact questions
Common questions
Is shaking at the spin transition normal?+
A slight shaking as the spin speed increases can be normal; mix small and large items.
What are transport bolts?+
Bolts that hold the drum for shipping; remove them before use.
Can lint block the pump?+
Yes; fabrics that give off fluff may cause a blockage.
Do metal objects matter?+
Metallic debris left in the drum can produce rust spots.