Genuine ZF Part 1250304388 Main Shaft (34 Splines) for Heavy-Duty Transmissions | Authorized ZF Parts Dealer

Genuine ZF Part 1250304388 Main Shaft (34 Splines) for Heavy-Duty Transmissions | Authorized ZF Parts Dealer

The main shaft is the backbone of any transmission, and when it comes to heavy-duty performance, there is no room for compromise. The ZF 1250304388 Main Shaft is a critical component designed to handle extreme torsional stress and deliver power consistently across all gears.

Featuring a precision-machined 34-spline design, this shaft ensures a perfect interface with your gears and synchronizers. As an established ZF parts dealer, we’ve seen how inferior aftermarket shafts lead to premature spline wear and vibration issues. By choosing this genuine ZF part, you are investing in the exact metallurgical standards and heat-treatment processes used by the original equipment manufacturer. Whether you are a fleet owner or a specialized repair shop, sourcing from a dedicated ZF parts supplier guarantees that your gearbox rebuild will last the distance.

Technical Specification

• Brand: ZF Transmissions (Original Equipment)

• Part Number: 1250304388

• Component Type: Transmission Main Shaft

• Spline Count: 34 Splines

• Material: High-grade case-hardened alloy steel

• Compatibility: Widely used in ZF Ecosplit and specialized commercial vehicle gearboxes (Please check your 10-digit ID plate for confirmation).

• Surface Finish: Micro-ground bearing journals for reduced heat and friction.

Simple Install Tip:

1. Check Spline Fitment: Before final assembly, slide your sliding sleeves and gears onto the new 34-spline shaft by hand. They should move freely without binding. If you feel resistance, check for debris or burrs on the mating components.

2. Replace Pilot Bearings & Seals: A new main shaft should never be paired with old bearings. Always replace the main shaft bearings and the input shaft pilot bearing to prevent misalignment that could snap the shaft under load.

3. End-Play Calibration: Proper shimming is vital. Use a dial indicator to measure the axial end-play of the shaft once it is seated in the housing. Incorrect clearance will lead to gear “jumping” or excessive heat buildup.

4. Lubricate During Assembly: Use a high-quality assembly lube on the splines and bearing surfaces. This protects the metal-on-metal contact during the critical first few seconds of operation before the pump circulates the transmission oil.

Packaging & Shipping

By Express :     Suitable for sample order or <50 KG        Fast:3-10 days       High shipping cost         Door to door service
By Air :   Suitable for >50 KG         Fast: 3-7 days       Lower than express cost         Airport to airport service
By Sea:   Suitable for >300 KG     Lower cost port to port service

As a leading supplier and dealer of ZF parts, we provide genuine components to maintain the integrity and efficiency of your gearbox system. Trust in our expertise and quality assurance to keep your ZF gearbox running smoothly.