The VTM-4 fluid uses SAE 75W-90 gear oil (GL-5) as its weight specification. This weight is standard for the rear differential and VTM-4 transfer mechanism in many Honda AWD models. Always check your owner’s manual or with a dealer for your specific model and year.
What is the VTM-4 system?
Honda’s Variable Torque Management 4WD (VTM-4) system relies on a dedicated rear differential/transfer mechanism that requires specific lubrication. The fluid is not engine oil or typical automatic transmission fluid; it is a gear-oil–style lubricant designed to protect the viscous coupling and related components while enabling precise torque distribution between axles.
Weight specification and official guidance
Official guidance for VTM-4 fluid centers on the weight specification rather than a standard engine or transmission fluid. The commonly cited specification is SAE 75W-90 gear oil (GL-5) for the VTM-4 system. If 75W-90 is unavailable, some regions or models may tolerate alternatives such as 80W-90, but this is not universally endorsed in every year/model. Always refer to your vehicle’s manual or a Honda dealer for the exact requirement.
Several options satisfy the VTM-4 fluid weight requirement. The list below summarizes the common specifications used in Honda AWD systems and by owners when replacing fluid:
- SAE 75W-90 gear oil (GL-5) — the standard specification for VTM-4 applications in most Honda manuals.
- SAE 80W-90 gear oil (GL-5) — sometimes used if 75W-90 is unavailable, but not the official spec for all models/year.
- Honda VTM-4 Fluid (dealer-sold) — the factory-recommended option, intended to match the precise formulation used in the vehicle, if available in your market.
In practice, the recommended approach is to use the weight specified in your manual and to source Honda VTM-4 Fluid or a high-quality 75W-90 GL-5 gear oil from reputable brands. Using the correct viscosity helps ensure proper engaging of the torque management system and longevity of the rear differential.
Model-year variations
Some model years or regions may have slightly different requirements or available fluid brands. Always verify with your dealer or the latest Honda service information for your specific vehicle.
Checking and replacing VTM-4 fluid
To check or replace VTM-4 fluid, follow the service interval in your owner's manual. The rear differential and transfer assembly are typically filled via a dedicated fill plug on the differential housing. If replacing, drain the old fluid, clean the fill plug, and refill to the specified level with the correct viscosity, then recheck for leaks.
Summary
The required weight for Honda VTM-4 fluid is SAE 75W-90 gear oil (GL-5) in most models, though check your manual and local dealer guidance for year- and region-specific requirements. Use Honda VTM-4 Fluid if available, or a reputable 75W-90 GL-5 gear oil as replacement, and ensure proper fill level during maintenance.