Diagnosis
The issue stems from a failure of the MyWay flexible third rack's locking detents to fully engage with the side-wall mounting brackets. In the Bosch 800 Series SHPM88Z75N, this rack is designed to be adjustable in height. When the rack is not pushed back with sufficient force or is slightly misaligned, the spring-loaded catches do not "snap" into the recessed sockets in the tub walls. Because the lower rack is physically large and often carries heavy pots and pans, pulling it out creates a slight vibration and mechanical shift in the tub chassis. If the third rack is barely holding on by a fraction of a millimeter, this vibration overcomes the friction of the loose detents, causing the rack to drop suddenly. You can confirm this by gently tugging the front of the third rack; if it wobbles significantly or slides back without resistance, the locking mechanism is not engaged.
How to Fix It
To properly secure the third rack and prevent it from collapsing during lower rack operation, follow these precise steps:
- Fully extend the lower rack and remove any oversized items that might be obstructing the upper cavity.
- Pull the third rack completely out of the dishwasher. Inspect the four plastic glide tabs (two on each side) for any cracks or accumulated detergent buildup that might be preventing a flush fit.
- Locate the mounting sockets on the left and right interior walls of the tub. Use a damp cloth to wipe out any food debris or hard-water scale from these sockets, as even a small pebble of debris can prevent the lock from clicking.
- Align the rack carefully. Instead of sliding it in horizontally, lift the front of the rack slightly (about 1/4 inch) as you push it back.
- Apply firm, steady pressure to the rear of the rack. You must feel and hear a distinct "click" on both the left and right sides. If you only hear one click, the rack is skewed and will eventually fall.
- Test the lock by pulling the rack forward firmly. It should resist movement until you manually trigger the release or pull it fully out.
If That Didn't Work
- Check for "Rack Sag" in the lower basket. If the lower rack's wheels are worn or the rack is overloaded, it may be hitting the underside of the third rack's support rails. Rearrange your heavy pots to the center of the lower rack to ensure there is a clear 2-inch gap between the top of the lower rack and the bottom of the third rack.
- Inspect the spring-loaded detents on the rack itself. If the plastic tabs are bent or the internal springs have lost tension, the rack will not hold. If you see a visible gap between the tab and the wall socket when the rack is "locked," the rack assembly (Part #00663110) likely needs replacement.
- Verify the tub alignment. In rare cases, if the dishwasher was not leveled perfectly during installation, the tub can slightly warp, causing the side sockets to be out of alignment. Use a spirit level on the top frame and adjust the leveling legs until the unit is perfectly plumb.
- Check for "ghost" obstructions. Ensure that no tall plates or oversized bowls in the middle rack are pushing upward against the third rack. Even a slight upward pressure from a large platter can lift the detents out of their sockets, making the rack prone to falling.
Heads Up
- Avoid overloading the third rack with heavy cutlery or heavy glass lids; it is designed for light utensils and espresso cups. Excessive weight can warp the plastic glides over time.
- Periodically clean the side-wall sockets with a toothbrush and white vinegar to remove lime scale, which can create a slippery surface that allows the rack to slide out of lock.
- When loading the lower rack, always slide it in completely and ensure it "seats" before closing the door to prevent the rack from shifting and jarring the upper components.
- If you notice the rack is sagging specifically on one side, check the rollers on the lower rack for debris; a stuck roller can cause the entire chassis to tilt slightly when pulled.