24V 6KW 12T Starter Motor STB4255UL for Dafu

Overview of the STB4255UL Starter Motor

The STB4255UL is a 24V, 6 kW starter motor supplied for Dafu. A reduction gearset between motor and pinion keeps the body compact while still delivering the cranking torque the engine needs.

Cranking load varies with temperature, battery condition and engine condition. A healthy starter has margin for all three; a worn one turns the engine just slowly enough that the control unit hesitates and the driver notices long, laboured starts.

Key Specifications

• Rated voltage: 24V
• Rated output: 6 kW
• Pinion: 12 teeth
• Type: reduction gear starter with pre-engaged solenoid
• Application: Dafu
• Net weight: approximately 9.5 kg
• Condition: new, direct replacement for the original unit

A 24V 6 kW rating is the output the motor can hold while cranking, not a peak figure. It is sized so the engine reaches starting speed on the first or second revolution, which is what makes a healthy start feel immediate.

The reduction gearset lets the motor run at high speed while the pinion turns slowly with high torque, which is why the unit stays compact enough for a crowded engine bay.

Reference Numbers and Cross References

Cross references for this starter are listed below. They are a matching aid rather than a substitute for checking the number on the old unit:

• 0001261046
• 0001261047
• 0001261071
• 0001261072
• 0986025900
• 0001261087
• 2134699
• STB4255UL

Cross references are a guide, not a fitment guarantee. The same engine family was often built with more than one starter, and the pinion module or terminal bracket can differ between them, so confirm the number on the unit being replaced. This starter is listed with 8 references in total.

Fitment and Application

Dafu applications in this range share the same mounting pattern and terminal layout, which is why one reference can serve several model years. Fitment is still decided by the starter number rather than by the badge on the vehicle. The STB4255UL is built to the same flange pattern as the unit it replaces.

When ordering for a fleet, quote the starter number from each vehicle rather than a single model reference; mixed build dates are common and the starter changed with them.

What Wears Out First

Oil or coolant mist from a leaking seal finds its way into the drive end housing, mixes with carbon dust and forms a conductive paste. The starter then arcs internally and fails early, whatever its mileage.

Most failures start at the solenoid contact. Each start switches the full cranking current through a copper disc, and after thousands of cycles that disc pits and burns. The result is the familiar single click with no rotation, or a delay before the motor turns. Where a STB4255UL has been replaced before, check that the fitted unit still matches the reference list.

Fault Symptoms

• Cranking that sounds normal but takes longer than it used to
• Several attempts needed before the motor engages
• Black carbon dust inside the drive end housing
• Voltage dip that dims the lights during cranking
• Starter that responds to a tap on the housing but not to the key alone

A cranking voltage test separates the starter from the rest of the circuit. If battery voltage stays healthy at the terminals but drops sharply at the starter stud, the cable or the connection is at fault rather than the motor. On Dafu installations, access to the STB4255UL usually decides how long the job takes.

What to Check Before Fitting

• Condition of the old pinion and ring gear before the new unit goes in
• Main cable continuity and the condition of the lug at the starter stud
• Battery voltage while cranking, measured at the battery posts
• Mounting face cleanliness and bolt condition
• That the replacement terminal layout matches the original harness

Most comebacks after a starter replacement trace back to something that was not checked before the unit went on: a tired battery, a corroded earth or a chipped ring gear. Ten minutes with a multimeter and a torch prevents the second repair.

Fitting Guidance

Isolate the battery, mark the terminal positions, then disconnect the main cable and the signal wire. Clean around the mounting flange before the starter is withdrawn so dirt does not fall into the bell housing.

After fitting, confirm the pinion returns freely and the cables are clear of the exhaust. Crank once before the first drive, then re-check the main terminal for tightness after the first heat cycle. For the STB4255UL, the practical check is the number stamped on the housing.

Quality Control and Supply from Hejian Nuojin Auto Parts Co., Ltd.

Hejian Nuojin Auto Parts Co., Ltd. manufactures starter and alternator components for the aftermarket. Every unit is bench tested for no-load current draw, solenoid pull-in and release voltage, pinion throw and running noise before packing.

Standard references are held as spot goods, volume orders are delivered in around 30 days, and every unit carries a one-year warranty against manufacturing defects.

Frequently Asked Questions

How do I confirm the starter matches my vehicle?

Compare the original part number first, then check the pinion tooth count and the terminal connector layout. The vehicle model alone is not enough, because more than one starter was fitted during production.

Should the ring gear be replaced at the same time?

Only if teeth are chipped, worn to a step or missing. Inspect the ring gear through the starter aperture before fitting the new unit.

Does this starter come with the solenoid?

Yes. The unit is supplied complete with its solenoid, as shown in the product photographs. Mounting bolts are not included.

Why does the starter click but not turn?

Most often the battery is low, a terminal is corroded or the solenoid contact is burnt. Measure battery voltage while the key is turned; a healthy battery that still gives only a click points to the solenoid.