How to Change the Oil in a 2020 Husqvarna TC85

Shop parts for a 2020 Husqvarna TC85 Dirt Bike.

Keeping your dirt bike’s transmission healthy is essential for top-notch performance—especially with a competition-ready two-stroke like the 2020 Husqvarna TC85. Changing the transmission oil on this bike is straightforward with some preparation and a few essential tools. Follow this MotoSport.com proprietary guide for step-by-step instructions, specific tips for the TC85, and a list of everything you’ll need to get the job done right.

Tools and Supplies Needed

  • 8 mm and 13 mm socket or T-handle (for drain and fill bolts)
  • Rag or shop towels (for spills and cleanup)
  • Oil drain pan
  • Measuring cup (500cc or larger)
  • Transmission/gear oil (see below for type and amount)
  • Small funnel
  • Replacement copper or aluminum crush washer (optional, but recommended for the drain bolt)
  • Latex or nitrile gloves (optional, but keeps hands clean)

Recommended Oil and Capacity

  • Type: High-quality 2-stroke gear/transmission oil (check your manual for brand and viscosity recommendations; Motorex 10W/40 or Bel-Ray Gear Saver 80W are common choices)
  • Capacity: 500cc (milliliters) of transmission oil is specified for the 2020 Husqvarna TC85

Step-by-Step Oil Change Instructions

  1. Warm up the engine (optional, but helps drainage):
    • Start your bike and let it idle for about two minutes. This thins out the oil for a more complete drain.
    • Turn off the bike and put it on a stand or level ground with the engine off for safety.
  2. Remove the oil filler cap and oil level bolt:
    • On the right side of the engine, locate the oil filler cap (usually plastic or aluminum) up high.
    • Below and slightly rearward, find the oil level bolt (8mm or 13mm depending on year/revision). Loosen and remove it.
  3. Remove the drain bolt:
    • Locate the drain bolt at the lowest point of the engine case, usually facing straight down. Place your drain pan directly beneath it.
    • Using the correct socket or T-handle, loosen and remove the drain bolt. (Be careful, oil may come out quickly if the bike was just running.)
    • Inspect the crush washer; replace it if it’s damaged or deformed.
  4. Allow oil to drain completely:
    • Tip the bike slightly side-to-side if necessary, but keep it upright to prevent spills.
    • Wait until the oil slows to a drip for maximum removal.
  5. Clean and reinstall the drain bolt:
    • Wipe any dirt, old oil, and debris from the bolt and engine case before reinstalling to avoid contamination.
    • Install a fresh crush washer if available.
    • Tighten the drain bolt snugly (do not overtighten; refer to the owner’s manual for spec, typically around 10 Nm).
  6. Pour in new transmission oil:
    • Using a measuring cup, add exactly 500cc of fresh transmission oil through the filler hole.
    • Use a funnel to avoid spills.
    • Reinstall the filler cap loosely for now.
  7. Check the oil level (specific to TC85):
    • With the bike upright and level, slowly remove the oil level screw while watching for oil seepage out of the hole.
    • The correct level is just at the bottom of the threads of the oil level screw; if it’s below, add oil in small increments. If it weeps out, let it drain to the correct level, then reinstall the bolt.
  8. Reinstall and tighten filler and level screws:
    • Ensure both are snug and secure (again, do not overtighten).
  9. Clean up and check for leaks:
    • Wipe down all surfaces with a clean rag.
    • Start the engine briefly, then turn it off. Double-check for leaks around the drain and filler bolts.
  10. Dispose of the used oil properly:
    • Pour old oil into a sealed container and take it to a recycling center or auto parts store that accepts waste oil.

2020 Husqvarna TC85 Specific Notes

  • The oil fill and drain locations are unique to the 85cc models; make sure you’re referencing the correct engine diagram if you’re unfamiliar.
  • The TC85 does not use a replaceable oil filter—just clean out the drain area and ensure no debris falls inside during the process.
  • Always use the correct amount of oil—overfilling can lead to pressure issues and leaks, underfilling risks transmission damage.
  • Change interval: For optimal engine protection, change the transmission oil every 5–10 hours of riding, or immediately after any muddy or wet rides.
  • Do not use engine oil intended for four-strokes or automotive engines in place of proper gear/transmission oil.

Final Tip

  • Take the time to inspect the drained oil for any visible metal shavings or milky color (which may indicate coolant contamination). These could be signs of internal wear or water ingress and warrant a professional inspection.

With routine oil changes using quality products, your 2020 Husqvarna TC85 will reward you with reliable shifts, strong performance, and a longer transmission life—so keep this guide handy for every maintenance session.

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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.