Gearboxes
Bethlehem Gear & Machine Division
- Service 02 / Core Equipment
Gearboxes.
Bethlehem Gear.
Bethlehem Gear.
Complete new gear drives, individual replacement gears, and full gearbox rebuilds — through Bethlehem Gear & Machine, our in-house gearing division. Spur, helical, bevel, worm. Any ratio, any size.
- Our Approach
The gear train is everything. We rebuild the whole train.
We work on gear drives from small auxiliary units to mill-sized pinion drives and reducers. Repair a single gear. Rebuild a full gearbox. Or engineer and manufacture a complete new gear drive to replace an obsolete unit.
When OEM drawings are lost or the original supplier has discontinued support, our engineering team reverse-engineers from sample or 3D scan. Your gearbox doesn’t have to retire just because the OEM did.
- Three Ways We Deliver
Cut new. Replace single gears.
Rebuild the whole drive.
01
New Gear Drives
Engineered and manufactured complete gear drives — from customer print or from our reverse-engineered design.
- Spur, helical, bevel, worm configurations
- Complete housings, shafts, bearings, seals
- Load tested and documented
- AGMA quality standards
02
Single Gears & Pinions
When only one gear is failing, we cut, grind, and ship that specific gear — no forced full-gearbox rebuild.
- Reverse-engineered from sample if needed
- Matching hardness, profile, and tooth geometry
- Fast turnaround on critical replacements
- Any module or diametral pitch
03
Full Rebuilds
Complete gearbox teardown, inspection, gear replacement, bearing replacement, housing rework, reassembly, and test.
- All gears and bearings replaced or inspected
- Housing crack-check and machining
- Bronze bushings cast in-house
- Full condition report documented
- Specifications
Gearing capability. Verified.
Maximum Gear OD96 in
Maximum Face Width36 in
Gear TypesSpur · Helical · Bevel · Worm
Module Range1 – 40 mm
Quality StandardsAGMA 10+ capable
Materials4140, 4340, 8620, 9310
Heat TreatmentInduction · Carburize (partner)
FinishingHobbing · Shaping · Grinding
- Types We Work On
Every gear. Every drive.
Spur Gears
Single gears through compound gear trains.
Helical Gears
Single and double helical, parallel axis drives.
Bevel Gears
Straight and spiral bevel for right-angle drives.
Worm Gears
Worm and wheel sets for high-reduction drives.
Pinion Drives
Mill pinion stands and main drive pinions.
Reducers
Single and multi-stage reduction gearboxes.
Open Gearing
Large exposed gear drives, girth gears, rack.
Obsolete OEM
Reverse-engineered replacements for discontinued units.
- What Powers the Work
Bethlehem Gear + the whole Mull ecosystem.
Gear Cutting Equipment
Dedicated gear hobbing, shaping, and grinding equipment at Bethlehem Gear — the gearing-focused division of Mull Group.
In-House Bronze Bushings
Worm wheels and bronze bushings cast on-site at Nail City Bronze — C93200, C95400, custom alloys available.
Reverse Engineering
Our mechanical engineering team rebuilds OEM drawings from sample, scan, or teardown. Obsolete doesn't mean unavailable.
