Collection: PRO 2HP 25L2 Electric Concrete Vibrator Parts by Northrock

Shop genuine OEM parts for the Northrock PRO 2HP 25L2 electric concrete vibrator motor. Click any numbered callout on the diagram below to jump to the exact part. Part numbers match the official Northrock PRO 1.5HP / 2HP / 3HP vibrator motor parts list.

DanseUSA is an authorized Northrock dealer. Orders placed before 12 PM ET ship same business day when in stock. Not sure which part? Email [email protected] with your motor's model and serial number.

How to Use the Diagram

Match the Ref # on the exploded view to the row in the parts list. Click the callout → product page → add to cart. Always replace wear parts (brushes, bearings, seals) in pairs.

Most Commonly Replaced Parts on the PRO 2HP (25L2)

About 80% of PRO 2HP service issues come down to these six parts. Diagnose in this order before replacing anything larger:

PRO 2HP (25L2) Full Parts List

Repair Tips

Brush replacement (Ref #8, P/N 490A1)

Unplug cord. Remove outer protective brush cap (400C1) and brush cap (500A1). Pull old brush. If carbon is under 1/4" or cracked, replace both brushes as a pair. Check commutator for glazing — light glaze is OK, grooves or pits mean the armature needs service. Reinstall caps finger-tight plus 1/8 turn.

Bearing replacement (Ref #5, P/N 140C300)

Two sealed bearings, one at each end of the armature. Always replace as a pair. Before running the motor again, pull the flex shaft core and check lubrication — a dry core cooks new bearings within 50 hours. Apply a 1/16" coat of lithium grease to the core; do not over-grease.

Model-specific parts — do not cross-swap

Several parts are unique to the 2 HP motor:

• Armature (475A1) — 2 HP only. The 1.5 HP uses 475B1; the 3 HP uses 475C1. Not interchangeable.
• Field (480A1) — 2 HP only. The 1.5 HP uses 480B1; the 3 HP uses 480C1. Not interchangeable.
• Motor Housing (105AD1) — shared with the 1.5 HP motor, but not the 3 HP (which uses 105AG1).
• End Bell Housing (420B1) — shared with the 1.5 HP, not the 3 HP (uses 420D1).
• Grounded Cord (505A1) — shared with the 1.5 HP. The 3 HP uses heavier-gauge 505B1.
• Strain Relief (435A1) — shared with the 1.5 HP. The 3 HP uses 435B1.
• Air Filter (470A1) and Cover (215N1) — shared with 1.5 HP. The 3 HP uses larger 470B1 with cover 215X1.
• Frame Assembly (440C1) — shared with 1.5 HP. The 3 HP uses 440D1.

Verify the part number against your motor before ordering — a 1.5 HP or 3 HP armature or field will not fit a 2 HP motor, even though they look similar.

Power cord + strain relief replacement (Ref #14, #15)

Do not tape damaged cords. Replace any cord with nicks, cracked jacket, or plug damage. On the 25L2, the grounded electric cord (505A1) and the water-tight strain relief (435A1) are separate parts — replace them together whenever either fails. A failed strain relief lets water into the motor and shorts the windings.

Switch + switch seal (Ref #11, #12)

Always replace the electric switch (425B1) and the water-resistant switch seal (430A1) together. A compromised seal lets water into the switch cavity and shorts the motor.

Air filter service (Ref #17, P/N 470A1)

Inspect every 40 hours. Replace when gray with embedded concrete dust. Never run the motor without the filter installed.

Maintenance Schedule

• Every shift: Inspect cord, plug, switch, housing. Clean concrete dust off exterior.
• Every 40 hrs: Clean or replace air filter.
• Every 50 hrs: Pull flex shaft core, inspect, re-grease with lithium grease (1/16" coat max).
• Every 200 hrs: Check brush length through service port cap (400B1). Replace pair if worn.
• Every 500 hrs: Inspect commutator for glazing or grooving.
• Annually (heavy use): Replace ball bearings.

Extension Cord Sizing (15 A draw)

Outdoor cords must be marked W-A (e.g. SOW-A). 3-conductor grounded only. Use a GFCI in damp conditions. Undersized cords cause voltage drop, which increases amp draw and burns brushes, armature, and field windings. At 15 A, the PRO 2HP runs on a standard 15 A or 20 A circuit, but a circuit already loaded with other tools will trip the breaker.

Shaft & Head Compatibility

Head diameter range

The PRO 2HP 25L2 is rated for the full Northrock head range — 3/4" through 2-1/2". Approved head sizes: 3/4", 1", 1-1/4", 1-1/2", 1-3/4", 2", and 2-1/2". This is the motor to buy if you want one power unit that drives every Northrock head size without swapping to a larger motor for big pours.

Shaft lengths

Compatible with Northrock standard-duty shafts (stiffer, better poking control) and pencil shafts (more flexible, used with 3/4" and 1-1/4" heads in rebar-dense work) in lengths from 2 ft to 21 ft. Maximum reach up to 60 ft using a Northrock shaft connector.

Multi-brand adapter chart

The PRO 2HP countershaft is universal. With the correct core adapter (Ref #21) and casing adapter (Ref #22), it runs shafts and heads from:

Brand not listed? Call +1 (202) 630-1027 or email [email protected] with your shaft brand, model, and head size.