Changing Drawer Runners: How to Correctly Replace Full Extension Slides

June 19, 2026

A full extension slide allows a drawer to be pulled out of the cabinet by 100%, which is why the exact overall length in millimetres and the lateral installation clearance are crucial when replacing them.

Replacing defective or outdated drawer runners is a standard task in furniture assembly and interior fitting. When a drawer jams, the guide grates, or an upgrade to a soft-close system is desired, the old runner must be removed and replaced with a suitable new component. This guide is aimed at fitters and experienced DIYers, covering the professional replacement of side-mounted ball bearing runners.

With proper preparation, replacing a pair of runners takes around 20 to 30 minutes. The difficulty level is intermediate – precise measuring and accurate marking out are essential prerequisites for smooth running.

System Check and Taking Measurements

Before replacement begins, the existing system must be analysed. The cabinet carcase is the running frame of the drawer – if the runners do not run parallel to the exact millimetre here, the entire mechanism will jam later.

First, determine the nominal length of the runner. This is measured in the closed state. Standard dimensions in furniture construction typically range between 250 mm - 800 mm. For example, if the old runner is 498 mm long, choose drawer runners 500 mm when buying replacements. For deeper carcase cabinets in kitchens or workshops, drawer runners 600 mm are frequently used. The new runner must never be longer than the internal depth of the cabinet.

Alongside the length, the installation clearance is the most critical factor. For classic side-mounted ball bearing slides, the required gap between the internal cabinet wall and the external drawer wall is usually exactly 12.7 mm (often rounded to 13 mm).

Distinguishing Mechanical Types

When selecting new drawer runners full extension, you must also define the required additional function. Two systems must never be confused here:

Soft-Close: An integrated damper cushions the momentum of the drawer over the last few centimetres and pulls it shut smoothly and silently.
Push-to-Open: A release mechanism that enables handleless fronts. Pressing the front causes the drawer to pop open.

These two mechanisms work physically against each other and cannot be combined in a single runner in standard fittings. If you want cushioned closing, choose drawer runners with soft close. If you are planning handleless fronts, fit drawer runners push to open.

Required Tools and Materials

The following tools are required for removal and installation:

Cordless screwdriver with matching bits (usually PZ or TX)
Tape measure or folding rule
Pencil and try square
Bradawl or awl for marking pilot holes
Chipboard screws (Ø 3.5 mm or 4 mm) with pan-head (flat head) or small countersunk head, typically 15 mm or 16 mm in length, matching the material thickness of the carcase.

Step-by-Step Guide: Replacing Full Extension Runners

The following instructions refer to replacing a classic three-part telescopic ball bearing runner that is screwed laterally to the drawer and carcase.

1. Remove the Drawer

To separate the runner, the drawer must be pulled out fully. On the sides of ball bearing runners (in the front third), there is a small plastic release lever. This lever must be pressed up on one side and down on the opposite side. While holding the levers down/up, pull the drawer forward out of the carcase profile.

2. Remove the Old Runners

Now the screwed profiles are accessible. Use the cordless screwdriver to remove all screws from the carcase profile. Next, unscrew the drawer profile attached to the side of the wooden drawer box.

3. Transfer Dimensions and Mark Out

If the old drill holes cannot be reused (for example because they are stripped or have a different hole pattern), you must mark out new lines. Draw a horizontal line on the carcase inner wall. This marks the centre axis of the new runner. On cabinets manufactured according to System 32, the existing hole lines with 32 mm spacing can often be used. Draw a central line on the outside of the drawer box as well.

4. Mount the Carcase Profile

Separate the three-part telescopic system of the new runner into its two main components by operating the plastic lever: the wide carcase profile and the narrow drawer profile. Position the carcase profile against the marked line inside the cabinet. Important: The runner is not fitted flush with the front edge of the carcase, but set back by about 2 mm. This ensures the drawer front sits neatly against the carcase later. First, insert the screws into the vertical slotted holes (elongated slots). The slotted hole allows for later height adjustment of about 1.5 mm up or down.

5. Mount the Drawer Profile

Screw the narrow profile onto the side of the drawer. Here, the runner is positioned exactly flush with the front edge of the drawer box (behind the front panel). Here, too, it is advisable to use the slotted holes first. On shorter slides, such as drawer runners 450 mm, three to four screws per side are usually sufficient.

6. Reassembly and Fine Adjustment

Pull the ball cage in the carcase profile all the way forward to the edge. Now insert the drawer with the fitted inner profiles horizontally into the carcase profiles. Push the drawer backwards with light, even pressure until the release levers audibly click into place.

Open and close the drawer several times. Does it run smoothly and does the front close flush? If so, carefully pull the drawer out again (without releasing it) and permanently secure the runners in position by driving screws into the round fixing holes.

Avoiding Common Installation Mistakes

Even with careful work, mistakes can occur that impair the running of the drawer.

Incorrect screw heads: A classic mistake is using countersunk screws that are too large. If the screw head protrudes even 1 mm above the metal of the runner, it will collide with the ball cage when closing. The runner jams or sustains irreparable damage. You must use screws that fit flush into the stamping of the runner.

Ignoring installation clearance: If the cabinet interior is 500 mm wide, the drawer including both runners must measure exactly 500 mm. Since each runner is 12.7 mm thick, the drawer box must be exactly 474.6 mm wide. If the box is even 2 mm too wide, the runners will jam. If it is too narrow, the ball cages may pop out. With drawers that are too narrow, you can remedy this by fitting washers between the carcase and the runner to bridge the distance.

Exceeding the load capacity: For standard residential drawers, standard slides with a load capacity of 30 kg to 45 kg are sufficient. However, if heavy tools, files, or heavy pots are to be stored, this specification is inadequate. In such cases, you must use heavy duty drawer runners. These often have a material thickness of 2 mm or more and can support loads from 80 kg to over 130 kg.

Alternative Runner Systems

Side-mounted ball bearing runners are not always the best choice. Depending on the piece of furniture, other systems may be fitted that must be identified during replacement.

If the runner is not on the side but hidden underneath the drawer base, it is an undermount runner. These require a completely different wooden drawer construction (the side walls must extend downwards past the base). When replacing these, you must use undermount drawer runners again.

If, on the other hand, you find a system with a simple plastic wheel running in an epoxy-coated metal profile, it is a roller runner. These are technically simpler, usually designed only as single extension, and have a lower load rating. A direct replacement with ball bearing full-extension slides is possible, but requires precise measuring of the installation clearance, as roller runners often have different tolerances. Replacement parts for this system can be found under roller drawer runners.

FAQ – Frequently Asked Questions

Can I replace a partial-extension runner with a full-extension runner? Yes, this is usually straightforward, provided both are side-mounted ball bearing runners and the installation clearance (usually 12.7 mm) is identical. The full extension offers the advantage that the drawer extends fully out of the carcase, leaving no blind spot at the rear.

How do I measure the length of the drawer runner correctly? The nominal length is always measured when completely closed. Measure the metal runner from the front edge to the rear end. The extension distance when open is not relevant for the ordering size.

Why does my newly fitted soft-close drawer not close properly? If the damper does not engage, this is often due to non-parallel installation. For example, if the distance between the runners at the front of the carcase is 450 mm, but 448 mm at the back, the runner jams over the final millimetres. The ball cage is slowed down before the soft-close mechanism pin can engage. Check the clear internal carcase dimensions at both the front and rear.

What does System 32 mean in cabinet making? System 32 is an international standard in furniture manufacturing. It specifies that the holes in the side walls of the carcase (for shelf supports, hinges, and runners) have a vertical spacing of exactly 32 mm from each other. The distance of the front row of holes to the front edge of the carcase is standardly 37 mm. Most modern drawer runners have hole patterns precisely aligned with this grid.

Related Categories for Your Project

To find the right hardware for replacing or building furniture, browse our specific categories. Depending on weight, length, and desired convenience, we offer the exact fittings for professional results: