WIT WHATEVER IT TAKES TRANSMISSION PARTS, INC Genuine GM Auto-Trak II Transfer Case Fluid 1L — Blue OEM Formula, High-Temp Stable

Genuine GM Auto-Trak II Transfer Case Fluid (1 L, GM Part No. 19540587) is the factory-specified fluid formulated for electronically controlled GM transfer cases to ensure smooth engagement, reliable clutch operation, and long-term protection.

If you own a GM truck or SUV equipped with an Auto-Trak or Active Transfer Case, using the correct fluid matters. This blue-tinted, OEM-formulated 1-liter fluid is developed to meet GM’s engineering requirements for modern AWD/4WD transfer cases, helping reduce shudder, manage torque transfer, and resist high-temperature breakdown during heavy use. It replaces part numbers 10-4017, 88900402, 12378396, and 12378508, making it a direct fit for service and maintenance work where factory specification and compatibility are priorities.

What does this transfer case fluid do for my vehicle?

The fluid provides precise clutch engagement and consistent friction characteristics that many electronically controlled transfer cases require. It lubricates internal gears and clutch packs while resisting oxidation and thermal degradation under load.

• Maintains clutch friction for consistent AWD/4WD engagement
• Reduces internal wear on gears, bearings, and seals
• Resists high temperatures to extend service intervals
• Blue tint helps technicians identify the correct fluid during service

How do I know this fluid fits my vehicle?

This is the genuine GM Auto-Trak II formula and is identified by part number 19540587. It’s intended for GM transfer cases that specify Auto-Trak II fluid; it replaces several legacy part numbers listed by GM.

• Check your owner’s manual or service guide for part 19540587
• Compatible with vehicles calling for Auto-Trak II or the replaced numbers
• Designed for electronically controlled transfer cases found on many GM trucks and SUVs

How does this fluid stand up under heavy towing or off-road use?

The formulation is engineered for high-temperature stability and oxidation resistance, which helps the transfer case tolerate heavier loads and prolonged operation. That stability supports longer life for internal components when your vehicle faces strenuous driving conditions.

• High-temperature resistance reduces fluid breakdown during heavy duty use
• Oxidation inhibitors slow varnish and deposit formation
• Friction modifiers help prevent shudder during torque transitions

How should I store and handle this fluid when servicing my vehicle?

Keep the 1-liter bottle sealed and stored upright in a cool, dry place away from direct sunlight. Use clean tools and funnels when filling the transfer case to avoid contamination and ensure correct fluid performance.

• Store in original, tightly sealed container at moderate temperatures
• Avoid mixing with other fluid types unless explicitly allowed by GM
• Use a clean funnel and follow factory fill and level procedures

Who is this for: This genuine GM Auto-Trak II Transfer Case Fluid is aimed at owners, technicians, and service shops working on GM trucks and SUVs that require GM Part No. 19540587 or its equivalents. It’s particularly valuable for those who prioritize OEM compatibility and want a fluid engineered to match the frictional and thermal demands of electronically controlled transfer cases. Whether you’re performing routine maintenance, preparing a vehicle for towing, or restoring optimal AWD/4WD operation, choosing the factory-specified fluid helps maintain the intended driveline behavior and longevity.