Full 25-point door and opener safety check with every visit - springs, cables, rollers, tracks, and your LiftMaster or Chamberlain opener included
You get a price before we start. It does not change when the truck arrives.
Genie Cable & Drum Replacement: The Concord Owner’s Guide
We stock and install Genie-compatible cable and drum assemblies for Concord homeowners, with most replacements completed same day at $130-$250 installed. The cable drum is the grooved wheel that winds and unwinds the lift cable as your door moves; when it cracks, strips, or seizes, the door hangs crooked or won’t move at all. Most owners notice the problem when one side of the door drops faster than the other, or when they spot a frayed cable collecting on the floor beneath the drum.
Which Genie Models This Applies To
Genie has used three main cable drum profiles across its residential opener lines: the standard 4-inch diameter drum found on chain-drive and belt-drive units from the ReliaG, IntelliG, and TriloG series; the compact 3.25-inch drum on older screw-drive models like the ProMax and PowerLift lines; and the heavy-duty 4.5-inch drum on the larger Excelerator and ChainLift 1200 units. The part number is stamped on the drum face, usually prefixed with 36764, 36765, or 38425, but wear can obscure it.
We carry OEM Genie drums and cables, plus quality aftermarket equivalents from Prime-Line and National Hardware that meet the same 7×19 aircraft-grade cable spec and cast-iron drum standard. For Concord homes built between 2005 and 2015, we see a lot of the 36764R assembly, which Genie discontinued in favor of a revised casting. The aftermarket version fits, but the cable anchor point sits 3/16-inch offset, so a direct swap without adjusting the cable length leaves the door 1.5 inches out of level. We measure and compensate for that on every job.
To identify your part: look for the model sticker on the opener power head, then check the drum itself for casting marks. If both are worn smooth, measure drum diameter across the grooves and count cable wraps at full door height. Bring those numbers when you call. We’re an independent service provider, not affiliated with Genie, so we source what actually fits rather than what a single catalog limits us to.
Signs Your Genie Cable & Drum Replacement Is Failing

- Door hangs crooked in the tracks. One cable drum has stopped turning freely, so the opposite side carries all the weight. The cable on the stuck drum usually piles up in loose loops or slips off the groove entirely.
- Grinding or clicking sound during open/close cycles. The drum’s internal spline is stripping where it meets the torsion tube. The noise is the metal teeth skipping under load. Left alone, the drum spins freely while the tube rotates, and the door loses all lift on that side.
- Frayed or kinked cable below the drum. A cracked drum groove pinches the cable during winding, breaking individual strands. The 7×19 construction means you can lose several strands before total failure, but the reduced cross-section is already beyond safe working load.
- Door falls rapidly when released manually. The drum’s helical groove is worn shallow, so the cable no longer grips during controlled unwind. This is common on Concord’s older homes near Todos Santos Plaza, where original hardware has cycled 15,000-plus times without service.
- Visible cracks or chips in the drum casting. Cast iron becomes brittle with thermal cycling. Concord’s inland valley heat, regularly hitting mid-90s in summer, accelerates this. A cracked drum can shatter under torsion load without warning.
Before
AfterReplacement Cost & What’s Included
| Service | Price Range (Concord) |
|---|---|
| Cable & drum replacement (single side) | $130-$250 |
| Cable & drum replacement (both sides) | $220-$400 |
| Cable only (drum reusable) | $130-$200 |
| Emergency same-day service | No additional charge |
The $130-$250 range covers a standard single-drum replacement with new cable: parts, labor, door rebalancing, and safety check. Both-sides jobs run higher because we also inspect torsion spring tension differential, which shifts when cables have been running unevenly. If your drum is cracked but the cable is intact, we still replace both together. The cable has been running on a damaged groove, and reusing it guarantees premature wear on the new drum.
Every job starts with a flat, written price and written scope before any work begins, per Clause 1 of The Haven Standard. No exceptions. We also photograph the failed drum and cable before quoting, so you see what we found. That’s Clause 4, the rule this company was built on in 2015. The 365-Day Done Right Promise covers the work. If it’s not right, we make it right.
DIY or Call Us?

There’s a safe middle ground here. You can inspect: pull the red emergency release, lift the door manually to waist height, and check whether both cables wind evenly onto their drums. Look for fraying, cracks in the casting, or cable that sits proud of the groove. Note the model numbers and drum measurements.
What you should not do is remove or adjust the cable while the torsion spring above the door remains wound. The spring stores enough torque to cause serious injury if the winding bar slips or the cable snaps free. Drum replacement requires releasing that tension with proper winding bars, then rewinding to the correct torque for your door’s weight and height. We’ve seen DIY attempts in Concord where the homeowner got the drum on but set the cable wrap count wrong, so the door bottomed out hard and bent the bottom panel. The repair then cost triple.
We carry Genie-compatible drums and cables on every truck, including the hard-to-source 36764R and the revised casting for newer units. Same-day availability is standard. Call (925) 940-6359 and tell me what it’s doing wrong, and I’ll tell you what it costs to fix it - before I touch anything.
FAQs
Most last 10,000 to 15,000 cycles, or roughly 8 to 12 years for a typical residential door. Concord’s summer heat and dry air accelerate casting brittleness, so we see more thermal-fatigue cracks here than in cooler Bay Area microclimates. Annual lubrication of the drum grooves and cable inspection extends service life. Call (925) 940-6359 for an exact quote on replacement - estimates are free.
No. Cast iron cannot be welded or bonded to withstand torsion cycling. Any repair attempt fails within weeks and risks sudden catastrophic separation. We replace with new OEM or equivalent-grade components and include the cable as part of the assembly. Call (925) 940-6359 for a written price before any work starts.
A single cable and drum replacement typically takes 45 to 75 minutes, including door rebalancing and safety testing. Both sides run 90 to 120 minutes because we also verify torsion spring torque differential and track alignment. We stock Genie-compatible parts on our trucks, so there’s no waiting on a supply run. Call (925) 940-6359 to schedule.
We stock Genie-compatible cable and drum assemblies on every service vehicle, including the discontinued 36764R and current-production equivalents for ReliaG, IntelliG, TriloG, and Excelerator lines. You do not need to source parts yourself. We also carry LiftMaster and Chamberlain equivalents for mixed-brand households. Call (925) 940-6359 - we’ll confirm fit by model or measurement and quote a flat, written price before dispatch.
Written by Marcus Deller, Owner, Servo Garage Doors Concord at Servo Garage Doors Concord, serving Concord and nearby areas.






Before
After
Before
After
Before
After