The Erskine 901778 is the high-flow version of Erskine’s 24-inch skid steer stump grinder. Its hydraulic motor is configured for carriers supplying 31–42 GPM, allowing contractors with high-flow skid steers or compact track loaders to use the carrier’s available hydraulic capacity for dedicated stump removal. The attachment retains the same direct-drive, bidirectional 24-inch wheel architecture as the standard-flow model.
Key Specifications
| Hydraulic flow | 31–42 GPM |
|---|---|
| Operating weight | 540 lb |
| Cutting wheel | 24 in. |
| Wheel speed | 900–1,200 RPM |
| Teeth | 32 carbide teeth |
| Max cutting diameter | 32 in. |
| Cutting depth | 8 in. below grade |
| Cutting arc | 55° |
| Case drain | Required |
1. Why high flow changes the fit
High-flow auxiliary hydraulics provide more oil volume to compatible attachments, but the attachment must be designed for that range. The 901778 is built specifically around 31–42 GPM rather than using the standard-flow motor from the 901777.
That distinction matters because hydraulic motors are selected for flow and pressure. A high-flow carrier should not simply be connected to a standard-flow attachment at unrestricted output. Matching the motor to the carrier is the proper way to use the available hydraulic system.
2. 24-inch commercial cutting wheel
The 24-inch wheel provides a substantial cutting diameter while keeping attachment weight around 540 lb. It is large enough for meaningful commercial stump work without requiring a separate dedicated grinder chassis.
Operators should think of wheel size as part of a system. A larger wheel gives reach and tooth coverage, but hydraulic power, wheel speed and tooth condition determine whether that potential becomes real production.
3. 900–1,200 RPM wheel speed
The published wheel-speed range reflects the high-flow motor configuration. Keeping the wheel inside its intended operating range allows the carbide teeth to cut effectively and clear material from the stump face.
If wheel speed drops repeatedly during a sweep, the operator may be taking too deep a bite or the hydraulic system may not be delivering expected flow. A steady controlled sweep generally produces better throughput than repeatedly stalling the wheel.
4. 32 carbide teeth and wear management
Thirty-two replaceable carbide teeth distribute the cutting work around the wheel. Tooth wear is one of the most direct operating costs in stump grinding because soil and hidden stone are abrasive.
Commercial crews should inspect for broken, rounded or missing teeth before each job and rotate or replace components according to manufacturer guidance. Uneven tooth condition can create vibration and reduce cutting efficiency.
5. Direct drive and maintenance
Erskine’s design eliminates a gearbox between the hydraulic motor and wheel. That simplifies the drivetrain and removes one lubricated gearbox from the maintenance schedule.
Hydraulic hoses, motor seals, bearings, fasteners and the case-drain circuit remain critical. High-flow systems move significant oil volume, so small restrictions or incorrect connections can create heat quickly.
6. Case drain requirements
The 901778 requires a case drain. That low-pressure return path helps protect the hydraulic motor from excessive internal housing pressure. The carrier needs the correct connection before the attachment is put into service.
This should be checked during the buying process rather than solved after delivery. If a carrier lacks the needed case drain, confirm an approved installation solution with the equipment manufacturer or qualified hydraulic service provider.
7. Commercial use cases
The 901778 fits tree-service companies, land-clearing contractors, municipalities and property-maintenance operations that already own high-flow carriers. It can be especially useful when a skid steer is already transporting brush, handling logs or cleaning the site.
Because the attachment can share a carrier with other tools, it can improve fleet utilization. The tradeoff is that the skid steer is committed to grinding while the attachment is in use.
8. 901778 versus 901777
Choose between these models from the carrier’s hydraulic output, not from the desire for the 'bigger' version. A 15–30 GPM machine belongs with the 901777; a compatible 31–42 GPM high-flow machine belongs with the 901778.
The cutting-wheel dimensions and general working envelope are similar. The motor configuration and resulting wheel-speed range are the important differences.
Buying Decision: Match the Grinder to the Carrier and Work
Stump grinder specifications only become useful when they are matched to the actual jobs and carrier. Record the stump diameters you encounter most often, typical wood species, site access, desired below-grade depth and how many stumps are completed in a normal day. Then compare those needs with hydraulic or PTO compatibility, cutting-wheel size and the amount of repositioning each attachment requires.
For commercial operators, include carrier utilization in the decision. An attachment can create strong ROI when it turns an existing skid steer or tractor into a revenue-producing grinder without adding another engine and trailer to the fleet. The tradeoff is that the carrier is committed while grinding. Parts support, tooth availability and service access should also be considered because downtime during tree-service season can cost more than a small difference in purchase price.
Ownership and First-Use Checklist
Before first use, verify every hydraulic, PTO, hitch and coupler requirement in the current manufacturer documentation. Inspect cutting teeth, fasteners, wheel condition, guards and mounting points. Establish a normal baseline for sound, vibration, wheel speed and hydraulic temperature before moving into heavy production.
After the first few jobs, inspect tooth wear and fastener torque again. Stump grinding works close to soil and hidden debris, so early inspection helps identify site-specific wear patterns. Keep a service log and replacement teeth available if the grinder will be used commercially.
Frequently Asked Questions
What hydraulic flow does the 901778 require?
31–42 GPM.
Does it use the same wheel size as the 901777?
Yes. Both use a 24-inch wheel with 32 carbide teeth.
Is a case drain required?
Yes.
How deep can it grind?
Up to about 8 inches below grade.
Should I buy it for a standard-flow skid steer?
No. The 901778 is intended for compatible high-flow carriers; the 901777 is the standard-flow model.
See This Erskine Stump Grinder
View current pricing, images, specifications, warranty information and shipping details at American Timber Equipment.
View Product Compare Stump Grinders