Oil Change Guide: 2026 Harley-Davidson Road Glide FLTRX

Harley-Davidson Road Glide FLTRX · 2026 · Oil Changes

Oil Change Guide: 2026 Harley-Davidson Road Glide FLTRX

Quick Reference Table

Spec	Value	Source
Engine	Milwaukee-Eight 117 (1,923cc)	Harley-Davidson
Oil Type	SAE 20W-50 (Harley-Davidson Formula+ or equivalent API SG+)	H-D Service Manual
Oil Capacity (with filter)	3.5 quarts (112 oz)	H-D Service Manual
Oil Capacity (no filter)	3.0 quarts	H-D Service Manual
OEM Oil Filter	Harley-Davidson 63731-99A	H-D Parts Catalog
Aftermarket Filter Alternatives	K&N KN-170, WIX 57089XP, HiFloFiltro HF204, Amsoil EA79	Cross-reference
Drain Plug Socket	3/8 inch hex socket	H-D Service Manual
Drain Plug Torque	14-18 ft-lbs	H-D Service Manual
Drain Plug Washer	Crush washer (copper or aluminum), replace every change	H-D Service Manual
Oil Filter Install	Hand-tighten plus 3/4 turn after gasket contact	H-D Service Manual
Service Interval	5,000 miles	H-D Owner Manual

Difficulty & Time Estimate

Difficulty Level: Beginner to Intermediate (1 out of 5)
Estimated Time: 45-60 minutes (first-timer: 60-75 min)
Best Done: On a warm engine (oil flows easier)

Complete Tool List

Tool	Size or Type	Purpose
Hex wrench or socket	3/8 inch (10mm)	Remove drain plug
Torque wrench	10-25 ft-lb range, 3/8 drive	Torque drain plug
Oil filter wrench	Cap style (76mm 14-flute) or strap type	Remove old filter
Oil drain pan	Minimum 6 quart capacity	Catch used oil
Funnel	Standard or motorcycle specific	Add new oil
New oil filter	OEM 63731-99A or aftermarket equivalent	Replace old filter
Drain plug washer	Copper or aluminum crush washer, new each time	Seal drain plug
Clean rags or paper towels	Several	Cleanup
Cardboard or mat	One piece	Protect floor
Jack or lift	Motorcycle rated	Elevate bike for access

Step by Step Instructions

Step 1: Warm the Engine

Run your bike for 5 to 10 minutes to warm the oil. Warm oil flows more completely and carries suspended contaminants. Do NOT change oil on a completely cold engine. Park on a level surface and let the bike sit for 2 to 3 minutes so oil drains back into the sump.

Step 2: Elevate the Bike

Place the motorcycle on a jack or lift so it is level and you have good access to the underside of the engine. Use jack stands for safety. Do not rely on a hydraulic jack alone.

Step 3: Remove the Oil Fill Cap

Remove the oil fill cap or dipstick from the top of the oil tank. This allows air in so the oil can drain freely. On most Milwaukee Eight Touring models, the fill cap is on the right side under the seat or accessible from the right side panel.

Step 4: Position the Drain Pan

Place your oil drain pan beneath the engine. Make sure it has at least 6 quart capacity.

Step 5: Remove the Drain Plug

Using a 3/8 inch hex wrench, loosen the drain plug on the bottom of the oil tank. Turn counterclockwise. Finish removing by hand, being ready for hot oil to flow immediately.

Warning: Oil may be hot. Wear gloves and eye protection.

Step 6: Drain All the Oil

Allow all oil to drain completely. This takes 10 to 15 minutes. While draining, inspect the drain plug and washer for damage, burrs, or excessive metal shavings.

Step 7: Replace the Drain Plug Washer

Remove the old crush washer from the drain plug. Replace it with a new one. Never reuse crush washers, they deform to make a seal and reusing them causes leaks.

Step 8: Reinstall the Drain Plug

Clean the drain plug and its threads. Install drain plug with the new washer, hand tighten, then use your torque wrench to tighten to 14 to 18 ft-lbs.

Important: Do not over-torque. Stripping the oil tank threads is an expensive repair. Always use a torque wrench, never guess.

Step 9: Remove the Old Oil Filter

The oil filter is typically located on the bottom or side of the oil tank on Milwaukee Eight engines. Position the drain pan beneath it. Use an oil filter wrench to loosen the filter, then spin it off by hand. Check that the old rubber gasket did not stick to the engine mounting surface (this causes major leaks if it does).

Step 10: Prepare the New Filter

Dip your finger in clean oil and rub a thin coat onto the rubber gasket of the new filter. This ensures a good seal and makes future removal easier. Verify the old filter gasket came off with the old filter.

Step 11: Install the New Filter

Screw the new filter on by hand. When the rubber gasket contacts the mounting surface, tighten it an additional 3/4 turn by hand. Do not use a wrench or filter tool to tighten the new filter. Hand tight only.

Step 12: Add New Oil

Using a funnel, pour 3 quarts of SAE 20W-50 motorcycle oil into the fill port. Use oil that meets Harley Davidson Formula+ specifications or API SG or higher. Do not use automotive oils with friction modifiers as they cause clutch slippage.

Step 13: Check the Oil Level

Install the dipstick or fill cap but do not fully tighten it yet
Start the engine and let it idle for 2 to 3 minutes to circulate the new oil through the filter
Turn off the engine and wait 1 to 2 minutes for oil to settle
Check the oil level with the dipstick (the bike should be level during this check)
If the level is low, add oil in small amounts (a quarter cup at a time) and recheck
Final oil level should be between the Add and Full marks on the dipstick

Step 14: Final Inspection

Check for leaks around the drain plug
Check for leaks around the oil filter
Tighten the oil fill cap or dipstick securely
Clean up any spilled oil
Reset service reminder if equipped

Tips, Warnings & Common Mistakes

Helpful Tips

Harley Davidson Formula+ semi or full synthetic oil is the OEM recommendation
Good alternatives: Mobil 1 V-Twin 20W-50, Amsoil V-Twin Synthetic, Castrol Power1 V-Twin 20W-50
Always verify JASO MA or MA2 rating on any oil for wet clutch compatibility
Change oil after long storage or before the riding season
Keep a maintenance log with date, mileage, and oil brand used
Check oil level before every ride, as Milwaukee-Eight engines can show some consumption

Warnings

NEVER use automotive oils with Energy Conserving labels or friction modifiers. These cause wet clutch slippage and damage the transmission.
NEVER start the engine without oil. This causes immediate and severe engine damage.
NEVER over-torque the drain plug. A stripped oil tank thread requires expensive repair.
Always use a motorcycle-specific oil filter. Some car filters do not have the correct bypass valve pressure.

Common Mistakes to Avoid

Mistake	Consequence	Prevention
Over-torquing drain plug	Stripped oil tank threads	Always use a torque wrench
Reusing drain plug washer	Oil leak after change	Always replace washer, keep extras on hand
Using car oil instead of motorcycle oil	Clutch slippage	Verify JASO MA or MA2 on label
Not checking oil level after fill	Engine damage from low oil	Start bike, wait, then recheck dipstick
Double-gasketing the filter	Massive oil leak	Confirm old gasket came off with old filter
Forgetting to remove fill cap before draining	Oil will not fully drain	Always remove the fill cap first

Oil Disposal

Used motor oil is hazardous waste and should never be poured down a drain, into the trash, or on the ground.

Pour the drained oil into a clean container with a tight fitting lid, such as the empty oil bottles
Take it to a certified recycling center. Most auto parts stores accept used oil for free: - AutoZone: Free oil recycling at all locations - OReilly Auto Parts: Free oil and filter recycling - Advance Auto Parts: Free oil recycling - NAPA Auto Parts: Accepts oil at most locations, call ahead to confirm
Take the old oil filter with you. These stores typically also recycle filters.
Your municipal recycling center or household hazardous waste facility is another option.
Never mix used oil with other automotive fluids (antifreeze, brake fluid, transmission fluid) as this makes recycling difficult or impossible.

Verification Notes for 2026 Model Year

The 2026 Road Glide received a new frame design compared to 2024 and earlier Touring models. The following specs should be verified against your owner's manual:

Item	Known Value	Notes
Oil capacity	3.5 quarts with filter	Based on Milwaukee-Eight Touring specs, verify for 2026 frame
Drain plug tool	3/8 inch hex	Standard Mil-8 spec, confirm on actual bike
Drain plug torque	14 to 18 ft-lbs	Standard Mil-8 spec, owner manual may differ
Filter location	Bottom or side of oil tank	New frame geometry may alter access
Oil fill location	Right side under seat area	May differ on 2026 frame

To verify all specifications, check your 2026 Road Glide owner's manual included with the motorcycle, or access it through the Harley-Davidson mobile app.

This guide was prepared using Milwaukee-Eight service manual specifications and Harley-Davidson OEM recommendations. Always verify against your specific owner's manual before performing maintenance.