Product Description
Upgrade the weak factory steering system in your GM HD truck with the PSC SG840R BIG BORE XD Cylinder Assist Steering Gearbox. Designed specifically for 1988-1999.5 GM 2500 and 3500 4WD trucks, this extreme-duty steering gearbox is engineered to handle oversized tires, locking differentials, and demanding off-road use. The SG840R features PSC’s Big Bore XD architecture with a larger piston and upgraded sector shaft bearing to increase torque output and eliminate sector shaft deflection under load. Unlike remanufactured steering gears that often fail under heavy loads, the PSC SG840R is a 100% new steering gearbox built to deliver superior durability, improved steering feel, and increased hydraulic output. The gearbox is ported for cylinder assist steering systems, allowing it to be used with PSC hydraulic steering assist cylinders for extreme off-road control and reliability. With its larger piston diameter and upgraded internal components, the PSC SG840R dramatically improves steering response and reduces steering effort when running oversized tires or heavy front-axle loads. Whether your truck is used for towing, off-road crawling, or heavy-duty work, this PSC Big Bore XD gearbox provides the steering strength and reliability serious builds demand.
Fitment
- 1988-1999.5 GM Silverado / Sierra 2500 4WD
- 1988-1999.5 GM Silverado / Sierra 3500 4WD
- Designed for GM solid-axle steering systems requiring a 3-bolt steering box
- Compatible with PSC hydraulic steering assist cylinder kits
Specifications for PSC SG840R
| Specification | Details |
|---|---|
| Manufacturer | PSC Steering Components |
| Part Number | SG840R |
| Steering Ratio | 13:1 Ratio / Approx. 3.25 Turns Lock-to-Lock |
| Sector Shaft | Upgraded 45mm Sector Shaft Bearing |
| Ports | -6AN Cylinder Assist Ports |
| Input Shaft | GM DD with 3/4-30 Spline Adapter |
| Mounting | 3-Bolt Inside-Frame Mount |
| UPC | 687927176812 |
| GTIN | 687927176812 |
| Shipping Info | Calculated at Checkout |
| Prop 65 | WARNING: Cancer and Reproductive Harm – https://www.P65Warnings.ca.gov |
Frequently Asked Questions
What does the PSC SG840R steering gearbox improve?
The SG840R improves steering torque, reduces steering play, and strengthens the steering system for trucks running oversized tires, heavy axles, or off-road setups.
Is this steering box compatible with hydraulic steering assist systems?
Yes. The SG840R comes pre-ported with -6AN ports for connection to PSC hydraulic steering assist cylinders.
Is this a remanufactured steering box?
No. The PSC SG840R is a brand-new steering gearbox built with upgraded internal components designed specifically for high-load steering applications.
What trucks does the SG840R fit?
It fits 1988-1999.5 GM Silverado and Sierra 2500/3500 4WD trucks equipped with the factory 3-bolt steering box configuration.
Why choose PSC Big Bore XD steering gearboxes?
PSC steering gearboxes use larger pistons, stronger sector shafts, and improved internal components to handle the extreme loads created by larger tires, heavy towing, and off-road driving.
