41A5434-13 full belt assembly for a 8 ft tall garage door — genuine LiftMaster OEM. Fits LiftMaster 2500, 2500B, 2500D, 2580, 2280, 3280, 3500, 3500D, 3850, 8550, 8550W and 8550WL, and the equivalent LiftMaster, Chamberlain and Sears Craftsman openers of that generation. Complete belt ready to fit, not a length of raw belting.
Specifications
| Part number | 41A5434-13 |
|---|---|
| Door height | 8 ft |
| Belt family | 41A5434 — the current LiftMaster belt drive generation |
| Fits | LiftMaster 2500, 2500B, 2500D, 2580, 2280, 3280, 3500, 3500D, 3850, 8550, 8550W and 8550WL |
| Type | Genuine LiftMaster OEM |
Is this the right belt?
Two things must match: the belt family and the door height. Get either wrong and it will not tension correctly.
| Check | This belt is right if… |
|---|---|
| The old belt | It is printed 41A5434-13 or 41A5434-13. The number is usually on the belt itself. |
| Opener model | 2500, 2580, 2280, 3280, 3500, 3850, 8550 or the equivalent of that era |
| Door height | 8 ft. Measure the door opening — not the old belt, in case the wrong length was fitted before. |
Other lengths in this family
| Door height | Genuine LiftMaster | Aftermarket |
|---|---|---|
| 7 ft | 41A5434-11 | 41A5434-11 aftermarket |
| 8 ft — this belt | 41A5434-13 | 41A5434-13 aftermarket |
| 10 ft | 41A5434-14 | 41A5434-14 aftermarket |
The 41A5434-13 aftermarket is the same length and fitment at roughly a third of the price. Genuine LiftMaster is the choice where a warranty or specification requires OEM.
Wrong family? The 41A3589 fits 1270, 1280, 1280R. The 041A5250 fits WD822K, WD912KS, WD922K, LW2000, LW3500. These are not interchangeable. See the belt and rail selector if you are unsure.
Is the belt actually the problem?
A belt drive that will not move the door is not always a failed belt. Before ordering, check:
| Symptom | Likely cause |
|---|---|
| Belt frayed, split or snapped | This belt |
| Belt intact but slack, will not hold tension | 41B4103 tensioner — far cheaper, and a common misdiagnosis |
| Belt pulled out of its anchor at the trolley | 041B5669 belt clip & link |
| Door releases on the cord but will not re-engage | 41B3869-1 trolley assembly |
| Grinding or squealing along the rail | 83A11-2 rail grease |
Common questions
Will this fit my 2500? Yes — LiftMaster 2500, 2500B, 2500D, 2580, 2280, 3280, 3500, 3500D, 3850, 8550, 8550W and 8550WL all take the 41A5434 family, in the length that matches your door.
Is it the same as a Chamberlain or Craftsman belt? Yes. LiftMaster, Chamberlain and Sears Craftsman openers of the same generation share the drivetrain, so this belt fits all three.
How do I know if I need the 8 ft one? Go by the door opening height, not the opener model. Measure the door.
Can I splice my old belt instead? Connectors exist — 29B129 for the 41A3589 series and 29B130 otherwise — but a spliced belt is a repair, not a fix. If it has stretched enough to need splicing, it is due for replacement.
Does it come with a trolley? No, this is the belt assembly only. For a complete rail with belt and trolley see the rail assemblies — those ship as oversized freight, so confirm the rail is genuinely damaged first.
Related
LiftMaster belt drive belts & rail parts · belt tensioner · trolley assembly · all garage door opener parts
Not sure which belt you need? Send us a photo of the old belt and your opener’s model number — parts@gatehousesupplies.com or 866-965-5599. We install and service this equipment and would rather confirm it than have you fit the wrong length. Since 1993.
