Snowplowing & Your Transmission: What You Need to Know
Plowing snow can be the most severe operation a transmission can operate. Sometimes we use the phrase "pushing a ton of snow", but it can be an understatement! We measured snow by weight and volume (varies with temperature, e.g. light snow vs. heavy snow) and its quite common to find 3,000 or more pounds of snow be pushed by a snow plow. That's a lot of work! Work equates to heat, a big factor in transmissions. The harder we work the plow truck, the more heat we generate. Even the best transmission cooling systems can't keep up!
Tip: When working with wet & heavy snow, take smaller sweeps and more time to allow heat to dissipate.
Next serious issues are mechanical energy (inertia) and hydraulic energy (pressure). There are a lot of heavy components in a 4 wheel drive turning and when directions are changed, these need to stop and change direction. This requires time for the "energy" (inertia) to dissipate. Think of spinning a ball on a string. When you stop spinning, the ball continues to travel until it dissipates the inertia. No different in transmissions, transfer case, drive shafts and axles. When we test transmissions on our dyno, if we change from forward to reverse abruptly, the "solid steel" drive shaft actually flexes! This "breaks" driveline parts quickly! Hydraulic energy is the other energy that causes damage to transmissions. When you change directions, the pressure in forward or reverse clutch (or band) circuits needs time to exhaust. When gear changes are too abrupt, we have hydraulic pressures in both forward and reverse circuits at the same time. Like driving your vehicle with the brakes on, it harms the transmission.
How to Prevent Damage to Your Transmission & Driveline Components
The only way to protect your transmission from this kind of damage is to take time between direction (gear) changes. Just like a manual transmission, the internal parts need to come to a stop!
- At the end of your pass (forward or backing up)
- Shift to Neutral
- Raise or lower the plow blade
- Shift into gear