CATTransmission Parts

6i-6518 19T Sun Gear — Cat Excavator 311 311B

This is a 19-tooth sun gear, a critical component within the planetary gear set of the transmission or final drive system. It is manufactured to meet stringent OEM quality standards, ensuring precise tooth engagement and durability, unlike a worn gear which may exhibit chipped teeth or excessive backlash. Operators may notice increased noise, vibration, or a loss of drive power when this component begins to fail.

19T Sun Gear – Part No 6i-6518 – CAT Spare Part
Part Specifications
BrandCAT
CategoryTransmission Parts
ConditionAftermarket — OEM Specification
DispatchSame-day from Mumbai (before 3 PM IST)
GST InvoiceAvailable — all orders
Export DocsCommercial invoice, packing list, COO

Compatible Models

Always verify with serial number before ordering.

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Installation & Application Notes

Drain and replace transmission fluid when servicing internal components. Use correct ATF specification. Pre-fill torque converters with fluid before installation. Allow 10 minutes for fluid to settle before checking level.

Always consult the OEM service manual for model-specific torque values and procedures. WhatsApp our technical team if you need fitment guidance.

Part TypeSun Gear
MaterialHardened Steel
ApplicationPlanetary gear set (transmission/final drive)
Service LifeReplace as needed based on inspection and performance
CompatibilityOEM specification
ConditionNew — OEM specification aftermarket

Failure Symptoms

Early signs of a failing sun gear may include whining or humming noises that change with speed, or slight play in the drive system. If left unaddressed, gear teeth can chip or break, leading to significant noise, vibration, and a potential loss of drive power or gear set seizure. This can result in transmission or final drive failure and immobilization of the machine.

Installation Tip

Ensure all mating gear teeth are clean and properly lubricated before assembly to prevent initial wear. Avoid forcing the gear into place; it should mesh smoothly with the corresponding gears.

Service Note

Inspect the planet gears, ring gear, bearings, and seals for wear or damage when replacing the sun gear.