Bollinger Edgerly HO Coupler Shims: Fix Coupler Height Fast
By Quality Tools & Supplies for Hobbys, DIY & Crafts - Micro-Mark Tools | Published: 2026-11-03
Category: How-to Guides
Use Bollinger Edgerly HO coupler shims to correct coupler height and mismatches in minutes. A step-by-step guide with checkpoints to avoid common mistakes.
Quick answer
Use .025-inch-thick Bollinger Edgerly HO coupler shims to raise low couplers or correct mismatches between cars. Install them between the coupler box and the frame, then test with a height gauge before running trains.
Why coupler height matters more than you think
Even a small height difference between couplers can cause missed connections, unwanted uncoupling, or derailments on curves and switches. Consistent height across your fleet keeps trains running smoothly and reduces frustration during operations.
When shims are the right fix—and when they aren't
Shims work best when a coupler sits too low or when two cars couple at different heights. If the coupler is too high, you may need to lower the coupler box or adjust the frame instead. Also check that the coupler itself is not damaged or misaligned; shims won't fix a bent shank or a worn coupler head.
Step-by-step coupler height adjustment
- Check current coupler height: Use an HO coupler height gauge to measure the height of the coupler on the car you want to adjust. Compare it to the standard height (typically .400 inch from railhead to coupler center). Record the measurement so you know how much correction is needed.
- Remove the coupler box: Carefully unscrew or unclip the coupler box from the car frame. Keep the screws and any existing shims in a safe place. Don't force plastic parts; if it's glued, consider a compatible replacement box.
- Add shims as needed: Place one or more .025-inch shims between the coupler box and the frame. Each shim raises the coupler by .025 inch. Start with one shim and test-fit. Avoid stacking more than three shims without checking screw length.
- Reassemble and recheck height: Reattach the coupler box and measure again with the gauge. Adjust by adding or removing shims until the coupler matches the standard height. Make sure the coupler moves freely and returns to center.
- Test with a mate: Couple the car to another car with a known-good coupler. Check that the knuckles mate smoothly and that there is no vertical play. Test on a section of track with a curve and a switch to catch interference.
Product facts
- Bollinger Edgerly HO Scale Coupler Shims (Pkg. of 75): Laser-cut shims are .025 inch thick and made from insulated-grade compressed paper. The consistent thickness lets you add or remove shims in predictable increments to fine-tune coupler height.
Bollinger Edgerly HO Scale Coupler Shims (Pkg. of 75) - Bollinger Edgerly HO Scale Coupler Shims (Pkg. of 75): The package includes 75 shims and is designed for exact fit with Kadee, McHenry, Intermountain, and Weaver couplers. You get enough shims for multiple cars, and the compatibility means less trimming or modification for common HO couplers.
