Volvo PT 1662 Transmission Fluid – What Works Best

[MikePhua]

Introduction
The Volvo PT 1662 transmission, commonly found in articulated dump trucks like the A35, requires the right transmission fluid to perform efficiently and remain reliable. Choosing the incorrect fluid—such as Dexron II, AW32 hydraulic oil, or even engine oil—can lead to premature wear, slippage, or costly repairs.
Recommended Fluid Type

• The correct specification for PT 1662 is Volvo AT 102, which corresponds to a synthetic Automatic Transmission Fluid (ATF). This is the consensus among experienced technicians.
  
• Many major oil manufacturers produce synthetic ATF formulations that meet the AT 102 specification.
  

Why It Matters

• Synthetic ATF (AT 102) offers stable viscosity across temperature ranges, strong wear protection, and reliable friction properties—essential for modern transmissions.
  
• Using Dexron II or hydraulic fluids risks inadequate lubrication, improper friction behavior, and accelerated component wear.
  
• Engine oil is entirely unsuitable due to incorrect additive packages and lubricity profiles.
  

OEM vs Aftermarket Choices

• Volvo’s own AT 102 fluid may be produced by suppliers like Mobil, and aftermarket equivalents from reputable brands often match its performance at a lower price.
  

Best Practices

• Always use AT 102 spec fluid specifically labeled compatible with Volvo transmissions.
  
• Confirm compatibility when purchasing aftermarket ATF—labeling or documentation should clearly state adherence to AT 102 or Volvo AT requirements.
  
• Stick to synthetic ATF formulations to maintain the transmission’s long-term reliability and shift performance.
  

Summary Table: Fluid Options

• Correct Option: Synthetic ATF meeting Volvo AT 102 spec — ensures proper lubrication and friction control.
  
• Not Recommended: Dexron II, AW32 hydraulic oil, engine oil — do not meet functional requirements.
  

Case Insight
A field mechanic shared that many operators mistakenly used generic hydraulic oils or Dexron variants in PT 1662 units until transmission performance degraded. Upon switching back to synthetic AT 102 spec fluid, normal gear engagement and smooth operation returned, avoiding potential damage and improving service life.
Conclusion
For the Volvo PT 1662 transmission, synthetic ATF meeting Volvo AT 102 specifications is the recommended and reliable choice. Avoid substituting with hydraulic or engine oils to preserve transmission integrity. Quality aftermarket products matching AT 102 spec offer effective and cost-efficient alternatives, keeping your Volvo drivetrain running smoothly.