How to Change the Oil in a 1999 Honda CR500: A MotoSport.com Proprietary Guide

Shop parts for a 1999 Honda CR500 Dirt Bike.

One of the most vital maintenance tasks for keeping your 1999 Honda CR500 running at peak performance is regularly changing its gearbox (transmission) oil. This two-stroke dirt bike doesn't use the same oil for the engine and transmission, so maintaining clean, fresh gear oil is critical for smooth shifting and a long lifespan for your internal components. Read on for a step-by-step guide tailored specifically to your ’99 CR500, including tools, tips, and expert call-outs for this legendary machine.

Tools & Supplies You’ll Need

  • Socket wrench set (particularly for the drain bolt and filler cap)
  • Drain pan (to catch used oil)
  • Measuring cup or bottle (marked in ounces, up to at least 25oz)
  • Funnel (small enough for the gearbox fill hole)
  • Shop rags (for spills and wipe-downs)
  • Fresh transmission/gear oil – See callout below for quantity and types
  • Gloves

Honda CR500 Gear Oil Type and Quantity

  • Oil capacity: For a routine oil change, use 23 US fluid ounces (about 680mL)

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  • Oil type: Honda recommends a high-quality motorcycle gear oil. Some owners use ATF (Automatic Transmission Fluid), but a dedicated motorcycle oil (like Pro Honda Gear Oil) is preferred for performance and longevity

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  • Pro Tip: If you’ve performed a complete engine disassembly and rebuild, use 25 US fluid ounces (about 740mL) to account for a totally empty case

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Step-By-Step Instructions

  1. Warm Up the Bike
    • Run the engine for a few minutes to bring the gearbox oil up to temperature. Warm oil flows and drains better, helping you remove more contaminants

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  2. Stabilize the Bike
    • Place your CR500 on a bike stand or crate so it remains upright and level throughout the process.
  3. Remove the Filler Cap
    • On the right side of the engine, locate the oil fill cap. Unscrew it before you remove the drain bolt. This prevents back pressure and allows the oil to drain out freely

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  4. Drain the Old Oil
    • Place your drain pan underneath the gearbox drain bolt (located on the underside of the engine on the right side).
    • Slowly loosen and remove the bolt with your wrench. Hot oil will drain quickly, so take care and use gloves if needed.
    • Allow all oil to drain fully. Tipping the bike slightly side to side can help get the last ounces out

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  5. Inspect and Clean
    • While oil drains, inspect the drain bolt for metal debris. Clean it off before reinstalling. Excessive metal shavings could indicate internal wear.
  6. Replace Drain Bolt
    • Once the flow has slowed to a drip, reinstall and securely tighten the drain bolt—don’t overtighten, as this can strip the threads in your aluminum case.
  7. Refill with Fresh Gear Oil
    • Use a measuring cup to pour exactly 23 US ounces (about 680mL) of high-quality transmission oil into the fill hole with a funnel

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    • Fill slowly to avoid spills or overfilling.
  8. Replace Fill Cap
    • Hand-tighten the fill cap, then snug with your wrench. Wipe away any spilled oil.
  9. Final Inspection and Clean-Up
    • Let the bike sit upright for a few minutes, then check for any leaks at the drain plug and fill cap areas.
    • Dispose of used oil responsibly, per local regulations.

Important Model-Specific Call-Outs for the 1999 Honda CR500

  • Oil Capacity & Spec: The 23oz fill is key; overfilling can lead to excessive clutch drag, while underfilling risks transmission wear

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  • Preferred Gear Oil: Although some riders use ATF, dedicated dirt bike gear oils offer improved protection and last longer in high-heat, high-load conditions typical for the CR500

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  • Drain Location: The drain bolt is easily accessible on the right underside of the engine, unique to CR500s from this era.
  • No Oil Filter: The 1999 CR500 gearbox does not have an oil filter, so be especially vigilant about oil cleanliness and regular change intervals.

Expert Tips from MotoSport.com

  • Always change your gear oil more frequently if riding in extreme conditions (muddy, wet, high RPM use) to maximize clutch and transmission life.
  • Monitor for fouling (milky or gray oil), which could indicate a failing crank seal letting coolant into your gearbox—a known issue on older two-strokes.
  • Keep a log of oil changes to help with long-term reliability and resale value.

MotoSport.com: Your One-Stop Garage for the Honda CR500

For all your Honda CR500 parts and gear oil needs, rely on MotoSport.com for the best products and expert advice. Regularly changing your transmission oil is the simplest investment you can make for enduring, reliable power on the track or trails.

Keep it fast. Keep it reliable. MotoSport.com—We Ride Too.

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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.