3RD/4TH SYNCHRONIZER CONE 1316304159 Mercedes Benz Truck Parts

1316304159 3rd/4th synchronizer cone for manual transmissions. Direct OE replacement component for gearbox overhaul. Bronze or sintered steel friction surface. No synchronizer ring, hub, or springs included. Verify transmission model and gear position before ordering.

The 1316304159 is a 3rd/4th gear synchronizer cone used in manual transmissions fitted to medium and heavy commercial vehicles. This component is essential for smooth gear engagement between third and fourth gears. The cone works together with the synchronizer ring and sliding sleeve to match shaft speeds before engagement.

The synchronizer cone is manufactured from high-strength steel with a friction lining applied to the conical surface. The friction material is either sintered bronze or a carbon-based composite, depending on the transmission generation. This lining provides the necessary coefficient of friction to synchronize the gear and shaft speeds within milliseconds of driver shift effort.

The inner spline mates with the gear wheel. The outer cone surface contacts the synchronizer ring. When the driver moves the shift lever, the synchronizer ring presses against this cone. Friction between the two surfaces equalizes rotational speeds, allowing the sliding sleeve to engage the gear without grinding.

This cone is specifically for the 3rd/4th synchronizer assembly. It is not interchangeable with 1st/2nd or 5th/6th cones due to different dimensions and friction angles. The part number 1316304159 is cast or stamped on the original component.

This replacement cone is suitable during a transmission rebuild when the original cone shows signs of glazing, scoring, worn friction material, or broken splines. Symptoms include difficult shifting into 3rd or 4th gear, grinding noises during engagement, or transmission jumping out of gear.

Installation notes: This synchronizer cone must be installed as part of a complete synchronizer assembly. Inspect the corresponding synchronizer ring (blocker ring) and sliding sleeve for wear. Replace all three components together for reliable shifting. Heat the cone slightly (80‑100°C) to ease installation onto the gear hub. Do not use force. Ensure the cone seats fully against the gear shoulder.

Compatibility check: Before ordering, confirm your transmission model. 1316304159 is commonly used in 6S‑1000, 6S‑1600, 9S‑109, and 16S‑221 series. Count the gear teeth on the old cone and measure the inner spline diameter. Mismatched splines will prevent installation.

Break‑in period: After replacement, avoid aggressive shifting for the first 500 km. The new friction surfaces require moderate use to bed in. Use the recommended transmission oil (GL‑4, not GL‑5) to prevent synchronizer damage.

Q1: Which transmissions use the 1316304159 synchronizer cone?
A1: This cone fits Ecomid (6S) and Ecosplit (9S, 16S) series transmissions. Common applications include MAN, , DAF, and trucks with gearboxes.

Q2: Is this cone for 3rd and 4th gear on the same assembly?
A2: Yes. The 3rd/4th synchronizer assembly uses one cone that serves both gears. The cone is installed on the 3rd gear side but affects 4th gear engagement through the same mechanism.

Q3: What is the difference between a synchronizer cone and a synchronizer ring?
A3: The cone is pressed onto the gear wheel. The ring (blocker ring) is a separate part that contacts the cone. Both must be replaced together for proper shifting.

Q4: How do I know if my synchronizer cone is worn?
A4: Signs include difficulty engaging 3rd or 4th gear, grinding noise when shifting into those gears, and transmission popping out of gear under load. Visual inspection will show glazed or worn friction material.

Q5: Can I replace only the synchronizer cone without replacing the ring?
A5: Not recommended. The ring and cone wear together. Replacing only one component leads to premature failure and poor shifting. Always replace the complete set.

Q6: What oil should I use with a new synchronizer cone?
A6: Use GL‑4 transmission oil. GL‑5 oil contains extreme pressure additives that attack yellow metals (bronze) and degrade friction linings. Check your transmission specification.

Q7: Does this cone require soaking before installation?
A7: No soaking is required. However, apply a thin film of transmission oil to the friction surface before assembly to prevent dry start scuffing.

Q8: Is this part compatible with automated manual transmissions (AMT)?
A8: No. AMT gearboxes use different synchronizer components. This cone is for fully manual transmissions only.