How to Identify Your Garage Door Bottom Bracket: Left vs. Right in Under 5 Minutes

A garage door bottom bracket, also called a bottom fixture, is labeled left hand (LH) or right hand (RH) based on where it sits when you stand inside the garage facing the closed door. The bracket on your left as you look at the door is the left hand bracket. The one on your right is the right hand bracket. Or, for less thinking, you can just always order the pair.

In this article

• What left hand and right hand mean on a bottom bracket
• How do I tell which bottom bracket I have
• Why the bracket has to match your door brand
• Step by step: replacing a bottom bracket safely
• Common mistakes when ordering bottom brackets
• FAQ

What do left hand and right hand mean on a bottom bracket?

Handing on garage door hardware is always read from inside the garage, facing the door as it hangs closed. Left hand (LH) and right hand (RH) brackets are mirror images of each other, not interchangeable parts. Each one bolts to the bottom corner of the door, holds the roller that rides in the vertical track, and anchors the lift cable that the spring system pulls on when the door opens. Because the cable attaches to a specific side, an LH bracket bolted onto the RH corner will not seat the cable correctly and can let the door hang unevenly.

How do I tell which bottom bracket I have?

Three ways to confirm handing before you order, in order of speed:

1. Stand inside the garage. Face the closed door from inside. The bracket nearest your left hand is LH. The bracket nearest your right hand is RH. This is the industry standard and the same convention used for torsion springs.
2. Look at the cable. The lift cable runs from the bottom bracket up to the drum on that same side. Whichever side the cable is anchored to tells you the side you are replacing.
3. Check the stamped part number. Many brackets have a part number stamped or molded into the steel. Overhead Door and Wayne Dalton brackets typically end in a number that differs between the LH and RH version (for example, one digit apart, like 0001 versus 0002). Match that number to the listing before you buy.

If your existing bracket is too rusted, bent, or worn to read, take a photo of both bottom corners of the door and compare them side by side. The mounting holes and the direction the roller stem points will mirror each other.

Why does the bracket have to match my door brand?

Bottom brackets are not universal across every door. They are sized to the track width, the roller stem, and in some cases the pin style the door manufacturer used. A bracket built for a 2 inch track will not seat correctly in a door built around a different track profile, and a Milford pin bracket will not work where a cotter and clevis pin fixture is expected. Matching brand and door series first, then confirming LH or RH second, is the fastest way to order the right part on the first try.

Door brand and series	Typical bottom bracket
Wayne Dalton 9100, 9400, 9600, 9800, Foamcore II	Wayne Dalton Residential Bottom Fixture
Overhead Door Thermacore 5720 / 2905, 1 inch and 1 3/8 inch panels	Overhead Door Bottom Fixture 408857
Overhead Door Thermacore 5760 / 490, Traditional Steel 1400 and 1500, 2 inch panels	Overhead Door Bottom Fixture 405771
Overhead Door 2 inch commercial, cotter and clevis pin style	Overhead Door Bottom Fixture 061141
Most other residential and light commercial doors, Milford pin style	Universal Bottom Fixture BB100

Not sure which row fits your door? Send us the brand and model stamped on the door panel or the old bracket, and we can confirm the correct fixture before you order.

Step by step: replacing a bottom bracket safely

Before you start: a bottom bracket anchors the lift cable, and that cable is under full spring tension whenever the door is closed and the springs are wound. NEVER LOOSEN OR REMOVE A BOTTOM BRACKET WHILE THE SPRINGS ARE UNDER TENSION. If you are not confident releasing spring tension safely, stop here and call a professional.

What you will need: winding bars or a locking C-clamp (per your spring system's instructions), a socket set, locking pliers or a second clamp to secure the door, replacement bracket, and safety glasses.

1. Step 1: Secure the door. With the door fully closed, clamp locking pliers onto the track just above the roller on both sides so the door cannot shift once tension is released.
2. Step 2: Release spring tension. Follow your spring system's release procedure completely before touching the bottom bracket. This is the step where injuries happen if it is rushed.
3. Step 3: Remove the cable from the bracket. Loosen the cable at the bottom bracket and set it aside without letting it snap back toward the drum.
4. Step 4: Unbolt the old bracket. Remove the bolts holding the bracket to the door section and lift the bracket off the roller stem.
5. Step 5: Install the new bracket. Confirm it is the correct hand, seat the roller stem, and bolt it back to the same holes.
6. Step 6: Reattach the cable and reset tension. Re-seat the cable in the bracket groove, remove the clamps, and restore spring tension per your system's instructions.
7. Step 7: Test. Open and close the door by hand (with the opener disconnected) a few times to confirm the door tracks straight and the cable stays seated.

Common mistakes when ordering bottom brackets

• Ordering only one side. If both brackets show wear, replace them in a pair. Mismatched age and wear on each side can make the door track unevenly.
• Guessing the track size. A 2 inch track bracket will not seat in a door built around a narrower track. Measure or match the old part before ordering.
• Ignoring the pin style. Milford pin, cotter and clevis pin, and slotted styles are not interchangeable. Check the old bracket or the door series against the table above.
• Working under spring tension. This is a safety mistake, not just an ordering one. Release tension fully before removing any bottom bracket.

While you have the bottom of the door open, it is a good time to lubricate the rollers and hinges so the whole door is running smoothly.

Frequently asked questions

Are bottom brackets sold individually or in pairs?

Both. Most Door-Parts.com bottom fixtures are sold as a left hand only, a right hand only, or a matched pair, so you can replace one side or both depending on the wear on your door.

Can I mix brands of bottom brackets on the same door?

It is not recommended. Track width, roller stem length, and pin style vary by manufacturer, so a bracket from a different brand may not seat correctly even if it looks similar.

How much does a garage door bottom bracket cost?

Residential bottom brackets typically run from about 7 to 10 dollars per side, or roughly 12 to 17 dollars for a matched pair, depending on the door brand and pin style.

Is it safe to replace a bottom bracket myself?

Yes, if you release spring tension completely and safely first. The bracket itself is a simple bolt on part. The risk is entirely in the stored spring tension on the cable, so if you have never released tension on your specific spring system, have a professional handle it or walk you through it the first time.

How do I know if my bottom bracket needs to be replaced?

Look for an elongated or worn pin hole, visible rust or cracking at the corner weld, a roller stem that wobbles in the bracket, or a door that hangs slightly crooked when closed. Any of these point to a worn bracket rather than a simple lubrication fix.