The counterpiece is a critical component in the exhaust valve brake system of the HOWO MAX 4X2 engine. A high quality counterpiece ensures proper actuation of the EVB mechanism, reducing engine braking noise and improving performance.
This genuine HOWO counterpiece kit includes the hexagon flange bolt, EVB pressure plate, hexagon nut M14X1, and adjusting screw. When you choose authentic Howo Parts, you receive a complete counterpiece assembly engineered for the MC13 engine.
The hexagon bolt with flange Q186 – M10X60 – 10.9 – MAN183 – B1 is a high-strength fastener used to secure the counterpiece assembly to the cylinder head. Two bolts are supplied, each made from alloy steel with a property class of 10.9. The bolt has a thread size of M10x1.5, a length of 60mm, and a flange head that distributes clamping load and eliminates the need for a separate washer.
The bolt is marked with MAN183, indicating it meets the stringent quality standards of the original engine manufacturer. In the counterpiece assembly, these bolts attach the EVB pressure plate to the cylinder head and must be torqued to 45 Nm plus an additional 90 degrees. The zinc‑nickel coating provides 720 hours of salt spray resistance, ensuring long‑term reliability.
The EVB pressure plate is a hardened steel plate that transfers the exhaust braking force from the rocker arm to the valve bridge. One plate is supplied, made from case‑hardened 42CrMo4 steel with a surface hardness of 55‑60 HRC. The plate has a thickness of 8mm and is precision ground on both sides to ensure flatness.
The pressure plate sits under the rocker arm and is actuated by the counterpiece during engine braking events. When the EVB system activates, the pressure plate applies a constant opening force to the exhaust valves, creating a braking effect. This counterpiece component is critical for the engine brake to function correctly; any wear or cracking will reduce braking performance.
The hexagon nut M14X1 is a fine‑pitch locking nut used to secure the adjusting screw on the counterpiece assembly. One nut is supplied, made from grade 10 steel with a zinc plating. The thread size is M14x1.0, which provides excellent resistance to loosening under engine vibration.
The nut is torqued to 25 Nm after the adjusting screw is set. In the counterpiece system, this nut locks the adjustment that controls the clearance between the pressure plate and the valve bridge. The counterpiece nut must be properly tightened to prevent the adjustment from changing, which would affect engine braking performance.
The adjusting screw is a hardened steel screw used to set the clearance between the EVB pressure plate and the valve bridge. One screw is supplied, made from case‑hardened steel with a hex socket drive. The screw has a thread size of M14x1.0 and a spherical tip that contacts the pressure plate.
The adjusting screw is turned to achieve the correct lash (typically 0.2‑0.3mm) when the engine is at top dead center. After adjustment, the hexagon nut is tightened to lock the screw. This counterpiece component is essential for proper EVB operation; incorrect clearance can cause weak braking or valve damage.
COUNTERPIECE – genuine HOWO EVB actuator and fastener kit
| Material Encoding | Name |
|---|---|
| MQ6-03216-8412 | Hexagon bolt with flange Q186 – M10X60 – 10.9 – MAN183 – B1 |
| 200V04251-0006 | EVB pressure plate |
| 200V90501-0083 | Hexagon nut M14X1 |
| 200V04205-0044 | Adjusting screw |
This counterpiece kit includes all the hardware needed to service the EVB pressure plate and its adjustment: the pressure plate itself, the adjusting screw, the locking nut, and the mounting bolts. No need to source individual parts.
The hexagon flange bolts are property class 10.9, and the hexagon nut is grade 10. These high‑strength fasteners provide secure clamping that resists loosening under engine vibration and thermal cycling.
The EVB pressure plate is ground flat on both sides to within 0.02mm, ensuring even contact with the rocker arm and valve bridge. This reduces wear and ensures consistent braking force.
All components carry the MAN183 mark or meet equivalent standards, guaranteeing they are manufactured under strict quality control and will perform reliably in the MC13 engine.
The counterpiece is the interface between the rocker arm and the exhaust valve bridge during engine braking. When the driver activates the exhaust brake, pressurized oil is sent to a piston inside the rocker arm, which pushes the counterpiece (EVB pressure plate) downward against the valve bridge.
This holds the exhaust valves slightly open during the compression stroke, creating a braking effect. The adjusting screw sets the correct clearance to prevent the pressure plate from contacting the valve bridge during normal operation. The hexagon nut locks the adjustment. The flange bolts secure the entire assembly. Without a properly functioning counterpiece, the exhaust brake will be ineffective or may cause valve damage.
Before installation, ensure the engine is at top dead center of the compression stroke for the cylinder being serviced. Remove the rocker arm cover. Clean the area around the EVB assembly. Install the EVB pressure plate under the rocker arm. Insert the adjusting screw into the rocker arm and thread it until it just contacts the pressure plate.
Back off the screw by a specified amount (typically 0.2‑0.3mm). Tighten the hexagon nut M14X1 to 25 Nm while holding the adjusting screw. Install the two hexagon flange bolts to secure the pressure plate bracket, torquing them to 45 Nm + 90°. Rotate the engine to verify no contact. Reinstall the rocker arm cover. The counterpiece is now correctly adjusted.
This counterpiece kit is designed for the MC13 engine used in the HOWO MAX 4X2 tractor. It fits the exhaust valve brake system on all cylinders.
The M10x60 bolts are specific to the EVB pressure plate mounting. The M14x1 adjusting screw is standard for this engine family. The kit is not compatible with the older MC11 engine. Always verify your engine serial number before ordering. For a full 6‑cylinder engine, you will need six kits (one per cylinder).
Check the counterpiece clearance during valve lash adjustments (every 100,000 km). If the engine brake feels weak, measure the clearance; if it exceeds specification, readjust.
Inspect the EVB pressure plate for cracks or wear; replace if any damage is found. The hexagon flange bolts should be retorqued after the first heat cycle. The adjusting screw tip may wear over time; if the tip is rounded, replace the screw and nut together. Always use genuine HOWO parts for any repairs to the counterpiece system.
If the exhaust brake is weak or non‑existent, the counterpiece clearance may be too large. Check and readjust. If there is a metallic rattling noise from the valve cover during braking,
the pressure plate may be loose or cracked. Inspect the plate and replace if necessary. If the adjusting screw will not stay locked, the hexagon nut may have stripped threads; replace both the nut and screw. If the flange bolts are loose, retorque them; if they have stretched, replace them with new bolts. A seized adjusting screw indicates corrosion; apply penetrating oil and replace the counterpiece components.
Aftermarket EVB pressure plates are often made from mild steel that wears quickly or cracks under thermal stress. Generic adjusting screws may have incorrect thread pitch or soft tips that mushroom. The lock nuts may be of lower grade and fail to hold adjustment.
The flange bolts may be class 8.8 instead of 10.9, leading to clamp load loss. Genuine HOWO counterpiece components are manufactured to the exact specifications of the original EVB system, using case‑hardened steel, precision ground surfaces, and high‑strength fasteners. The small additional cost is far outweighed by the safety and reliability of a properly functioning exhaust brake.
All components are supplied in a recyclable cardboard box with foam inserts. The fasteners are in sealed poly bags. The manufacturing facility is ISO 14001 certified. No hazardous substances are used in the production of these parts. The counterpiece kit is environmentally responsible.
This counterpiece kit includes all four line items listed in the parameters table.
Individual components can be ordered separately using their material encodings. Authorized HOWO dealers in Nigeria stock these genuine parts. For fleet orders of six or more kits (a full engine set), volume discounts are available. Always provide your engine serial number to confirm compatibility.
Fleet managers who have installed this genuine HOWO counterpiece kit report restored exhaust brake performance and reduced valve train noise. The precision‑ground pressure plate has eliminated rattling. The adjusting screw has held its setting without loosening. Many operators have standardized on this kit for all MC13 engine brake repairs, citing the complete nature and the high quality of the genuine components.
The kit is shipped in a sturdy cardboard box measuring 20cm x 15cm x 10cm, weight 0.8 kg. Store the kit in a dry indoor area. Do not remove the protective oil from the pressure plate until installation. The shelf life is five years when stored properly. Protect the adjusting screw tip from damage by not dropping the box.
We are a heavy-duty truck parts store. Please leave your contact information and inquiries. We will respond within 12 hours.
