Bosch SHXM78W55N (800 Series with MyWay) – Third rack adjuster broken Repair Guide

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Model: Bosch SHXM78W55N (800 Series with MyWay)
Brand: Bosch
Model Number: SHXM78W55N

🔍 Problem Description

Replace rack slide mechanism; check for obstructions

📋 What You’ll Need

  • Third rack slide mechanism

    • 🔧 Step-by-Step Repair Instructions

      🔧 Step 1: Inspect third rack adjuster mechanism

      1. Open the dishwasher door fully until it rests in the horizontal position.
      2. Pull the third rack completely out of the dishwasher cavity until it stops at the end of its travel path.
      3. Locate the height adjustment levers on both the left and right sides of the third rack – these are gray plastic levers positioned on the outer rail assembly, approximately 2 inches from the front edge of the rack.
      4. Press down on the left adjustment lever and observe whether it moves smoothly through its range of motion (approximately 1 inch of vertical travel).
      5. Release the lever and verify it returns to its locked position with an audible click.
      6. Repeat the press-and-release test on the right adjustment lever, checking for the same smooth movement and click.
      7. Examine both adjustment mechanisms for cracked or broken plastic tabs – these tabs are rectangular protrusions measuring approximately 0.25 inches that engage with notches in the rail assembly.
      8. Look for white or gray plastic fragments in the bottom of the third rack or on the lower spray arm, indicating broken adjuster components.
      9. Grasp the third rack with both hands at the front corners and attempt to lift it upward – movement exceeding 0.5 inches indicates worn or damaged height adjustment mechanisms.
      10. Inspect the metal rail guides that run along both sides of the third rack for visible bends, dents, or separation from the rack frame.
      11. Check where the adjuster mechanism connects to the main rail (approximately 3 inches from the front of the rack) for any gaps exceeding 0.125 inches between components.
      12. Verify that both left and right adjusters are set at the same height position by measuring the distance from the bottom of the third rack to the top of the second rack – this should be identical on both sides, approximately 4-5 inches depending on current setting.

      🛠️ Step 2: Check for obstructions in rack slides

      1. Pull the lower dish rack completely out of the dishwasher until it stops at the full extension point (approximately 20 inches from the closed position).
      2. Look at the left side metal rack slide rail and identify the white or gray plastic roller wheels – there are typically 2 wheels positioned at the front and rear of each slide assembly.
      3. Run your fingers along the entire length of the left side rack slide channel, feeling for food debris, broken plastic pieces, or small utensils wedged in the track – pay special attention to the curved rear section where items commonly lodge.
      4. Remove any obstructions you find by hand or use needle-nose pliers (6-inch length) to extract items stuck in tight spaces.
      5. Repeat the inspection on the right side rack slide, checking both roller wheels and the full channel length from front to back.
      6. Lift the lower rack straight up approximately 1 inch while pulling forward to fully remove it from the dishwasher – the rack will disengage from both slide rails when lifted at this angle.
      7. With the rack removed, inspect the fixed metal slide rails mounted inside the dishwasher tub on both left and right sides – these rails are approximately 18 inches long and positioned 3 inches above the bottom of the tub.
      8. Wipe the metal slide rails with a damp cloth to remove grease buildup, food particles, or detergent residue.
      9. Pull the upper rack forward 12 inches and repeat the inspection process on its left and right slide assemblies, checking the 4 roller wheels (2 per side) and the metal tracks.
      10. For the upper rack slides, also check the height adjustment mechanisms located at the front corners – these rectangular plastic blocks should move freely up and down when you press the release tabs.
      11. Reinsert the lower rack by aligning the rack slide ends with the metal rails and pushing straight back until fully seated – you’ll feel resistance stop when properly positioned.

      ⚙️ Step 3: Test rack adjustment operation

      1. Open the dishwasher door fully until it rests horizontally at approximately 90 degrees from the closed position.
      2. Locate the upper rack adjustment levers on both the left and right sides of the upper rack, positioned at the front corners where the rack meets the roller assemblies.
      3. Pull the left adjustment lever outward (away from the rack) approximately 1 inch while simultaneously lifting the entire left side of the upper rack upward with your other hand.
      4. Raise the left side until you hear and feel a distinct click, indicating the rack has engaged the next height position (approximately 2 inches higher than the starting position).
      5. Release the adjustment lever and verify the left side stays locked in the raised position by applying 5-10 pounds of downward pressure on the rack corner.
      6. Repeat steps 3-5 on the right side, pulling the right adjustment lever outward while lifting the right side of the rack until it clicks into the matching height position.
      7. Visually confirm both sides are level by looking across the top rail of the upper rack from front to back—the rack should appear parallel to the door opening with no tilt.
      8. Pull both adjustment levers outward simultaneously and push the entire rack downward until it clicks into the lowest position (original starting height).
      9. Slide the upper rack forward on its rails until it extends 8-10 inches out of the dishwasher cavity, then push it back to the fully retracted position, repeating this motion 3 times to verify smooth rolling operation.
      10. Listen for any grinding, scraping, or squeaking sounds during the sliding motion—the rack should move silently with minimal resistance (requiring less than 5 pounds of pushing force).
      11. Place a standard 12-inch dinner plate in the upper rack and verify it sits flat without wobbling, confirming the rack rollers are properly aligned and functioning.

      🔩 Step 4: Replace rack slide mechanism

      1. Position the new left slide rail assembly (part number 00428344 or 00612072) at the left sidewall mounting points, aligning the rear hook with the opening 2 inches from the back wall, 3 inches up from the bottom of the tub.
      2. Push the rear hook into the slot until it clicks into place – you’ll hear an audible snap and the rail will be flush against the tub wall.
      3. Pivot the front end of the rail downward and align the front mounting tab with the rectangular opening 2 inches from the front door opening, 3 inches up from the bottom.
      4. Press firmly on the front tab until it snaps into the mounting slot – the rail should now sit level and not move when pulled.
      5. Repeat steps 1-4 for the right side rail assembly, ensuring both rails are at identical heights by measuring from the tub floor to the bottom edge of each rail (should be 3 inches on both sides).
      6. Extend both new slide mechanisms fully outward by pulling the inner glide sections forward until they stop.
      7. Lift the dish rack and align the metal mounting brackets on each side of the rack with the extended glide sections – the brackets have a hooked front edge and flat rear tab.
      8. Insert the rear tabs of the rack brackets into the rear slots of the slide mechanisms on both sides simultaneously, tilting the rack at a 15-degree angle.
      9. Lower the front of the rack until the hooked front edges snap over the front lip of the slide mechanisms – you’ll feel resistance, then a click on each side.
      10. Push the rack fully closed into the dishwasher – it should glide smoothly without binding or tilting side-to-side, stopping 1 inch from the front edge of the tub opening.

      📋 Step 5: Test rack movement

      1. Open the dishwasher door until it rests horizontally at approximately 45 degrees from vertical.
      2. Grasp the lower rack by its front edge with both hands, positioned 8-10 inches apart near the center.
      3. Pull the lower rack straight toward you with steady pressure until it reaches the front stop position – you’ll feel resistance approximately 22 inches from the fully closed position.
      4. Push the rack back into the dishwasher cavity until it stops against the rear wall – the movement should be smooth without grinding, clicking, or catching.
      5. Repeat the pull-and-push motion 5-6 times to verify the rack glides consistently on both left and right roller assemblies.
      6. With the lower rack fully extended, apply downward pressure of 5-8 pounds on the front corners – the rack should remain stable without tilting or dropping on either side.
      7. Load 3-4 dinner plates (approximately 10-12 inches diameter) into the lower rack’s rear tine rows to test with weight.
      8. Pull the loaded rack outward again – it should extend smoothly without binding, requiring no more force than the empty rack.
      9. Remove test plates and push the lower rack fully closed.
      10. Grasp the upper rack handle at the center front and pull it forward until the rack stops – this occurs at approximately 16 inches of travel when the front wheels reach their track limits.
      11. Push the upper rack back until it seats against the rear spray arm assembly with a soft contact.
      12. Pull and push the upper rack 5-6 times, checking that both left and right sides move in sync without one side leading or lagging.
      13. Lift upward on the front center of the upper rack – it should not rise more than 1/4 inch, indicating the rack height adjusters are properly engaged in their tracks.
      14. Close the dishwasher door completely – both racks should rest in their fully retracted positions without protruding.

      🛒 Recommended Products

      Here are the recommended products for this repair: