SADEV 4th Gear Pinion 23 Teeth ST66 Gearbox – Clio 2 Gr N (F1903003)

A Worn 4th Gear Pinion = A Missed Shift, Loss of Competitiveness

4th gear is often a crucial ratio in rally, heavily solicited during the transition to high speed. The SADEV 4th gear pinion, 23 teeth (P/N: F1903003) of your Renault Clio 2 Gr N (ST66 dog-ring gearbox) is designed to withstand full load. If the dog rings or teeth of this pinion are damaged, you will instantly lose the efficiency of your transmission. A missed or slow gear change at this crucial stage can cost you valuable seconds and control.

The Consequences of a Defective 4th Gear Pinion

• Frequent Gear Jumps: Worn dog rings on the male pinion no longer engage correctly with the dog collar, causing a 4th gear jump under load. This is one of the most serious risks during full acceleration.
• Accelerated Wear on Mating Parts: A pinion with imperfect teeth (F1903003) leads to premature wear of its counter-part, the 4th gear wheel, 26 teeth. Replacing one without the other is a false calculation of reliability.
• Increased Shift Time: The degradation of the dog rings makes engagement more difficult and slower, reducing the advantage of the gear control system and increasing lever effort.

SADEV Pinion F1903003: Competition Steel and Machining Precision

The SADEV 4th gear pinion, 23 teeth is manufactured from high-strength steel, treated to ensure maximum longevity even under the toughest stresses of motorsport competition. Optimiz Access supplies you with this essential component for:

• Renault Clio 2 Gr N (ST66 Gearbox)
• Renault Clio 2 X65 Cup
• Renault Clio 3 X85 Cup
• Renault Megane N4
• Twingo R2

Maintenance Questions for the 4th Gear Ratio

Should I replace the 4th gear wheel (26 teeth) at the same time?

Yes, it is highly recommended to replace the pair: 4th gear pinion, 23 teeth (F1903003) and 4th gear wheel, 26 teeth (complementary product available at the bottom of the page). These two parts work together and are subject to joint wear. Installing a new pinion on a worn wheel would compromise reliability.

What are the signs of dog ring wear?

Wear on the dog rings manifests as rounded or chamfered edges rather than sharp ones. This reduces the locking efficiency and is the main cause of gear jump. Visual inspection is crucial during gearbox overhaul.

Our Service: Authentic SADEV Parts and Technical Installation

As a specialist in sports vehicle customization, Optimiz Access ensures you fast delivery of this pinion. Our technicians, based near Seclin and Lille in the Hauts-de-France region, are qualified for the professional installation and reassembly of your ST66 dog-ring gearbox.