Forging Gearbox & Hydraulic Repair
Press drives and forging equipment rebuilt for shock loads and heavy, repeated cycles — with rush repair available when a press is down.
Gearbox & Pump Repair for Forging
Rebuilt at our Rialto, CA shop.
Forging equipment lives on shock loads. Every press stroke, hammer blow and upset sends a shock through the drive train, and over time that shows up as cracked teeth, spalled bearings, twisted shafts and loosened housings. American Gearbox Repair rebuilds forging press gearboxes, manufactures replacement gears and repairs hydraulic cylinders at our shop in Rialto, California, serving forging operations across California and nationwide.
A press earns nothing while it is down, so we inspect first, quote the full repair, and rebuild the unit for shock-load service, backed by a 24-month warranty.
Equipment We Repair in Forging
- Mechanical press gearboxes — main drive gearboxes for eccentric, crank and knuckle-joint presses, including bull gears, pinions and clutch-related gearing.
- Hammer and upsetter drives — gearboxes and gear sets subject to repeated impact loading, checked for tooth root cracking and shaft fatigue.
- Manipulator and handling drives — gearboxes on manipulators, tongs and transfer equipment that position hot workpieces under load.
- Trim press and shear drives — smaller high-cycle drives where wear accumulates quickly and clearances matter.
- Hydraulic cylinders — press, ejector and die-cushion cylinders — resealed, re-rodded and re-honed, with rod and bore condition checked closely.
- Pumps for hydraulic and cooling systems — hydraulic and coolant pumps repaired so the press and its support systems come back together.
Common Failures We See
- Tooth breakage and root cracking — from repeated impact and overload on press gearing.
- Bearing spalling and brinelling — caused by shock loads transmitted through the gear mesh.
- Shaft bending and keyway damage — from sudden load spikes and worn couplings.
- Cylinder rod scoring and seal failure — from heat, scale and side loading on press cylinders.
- Oil contamination — scale and metal particles in the lubricant accelerating wear in every drive on the line.
Repair & Rebuilding Services
- Complete gearbox rebuilding — full teardown, inspection and rebuild with new gears, bearings, shafts and seals as required.
- Custom gear manufacturing — replacement gears cut to match the original, including large bull gears and pinions that are no longer stocked.
- Hydraulic cylinder repair — reseal, re-rod, re-hone and test, with attention to rod straightness and chrome condition.
- Industrial pump repair — hydraulic system and cooling pumps rebuilt and tested.
- Expedited inspection and quoting — so you can decide quickly whether to rebuild, replace a gear, or plan the work around production.
Emergency & Rush Service
When a line is down, call (714) 204-5167 — emergency service is available 24/7. We arrange emergency pickup and delivery to our Rialto shop, prioritise inspection, and, on qualifying jobs, complete rush repairs in 24–72 hours. Rush timing depends on unit condition, parts availability and job complexity, so we confirm a realistic schedule after inspection. See our emergency repair page.
How a Repair Works
Repairs are done at our shop in Rialto, California — we do not repair equipment on your site. Ship your unit to us, or arrange emergency pickup and delivery. We inspect it, confirm the failure and parts needed, and quote the repair before work starts. Turnaround depends on equipment condition, parts required, job complexity and availability. Rebuilt units are tested where applicable and covered by our 24-month warranty. Call (714) 204-5167 or request a quote with the brand, model and problem.
Get Started
If a press drive is noisy, losing power or leaking, call (714) 204-5167 before the damage spreads to the housing or the bull gear — early inspection usually keeps the repair smaller and faster. Call (714) 204-5167 or request a quote.
Need a repair quoted?
Call (714) 204-5167 or send a quote request — we will confirm what to send in and how pickup works.