Oil Change Guide: 2025 Harley-Davidson Tri Glide Ultra FLHTCUTG

Harley-Davidson Tri Glide Ultra FLHTCUTG · 2025 · Oil Changes

Oil Change Guide: 2025 Harley-Davidson Tri Glide Ultra FLHTCUTG

Quick Reference Table

Spec	Value	Source
Engine	Milwaukee-Eight 114 (1,868cc, air-cooled)	Harley-Davidson
Frame Platform	Trike (Touring-based FL frame with rear differential and dual wheels)	Harley-Davidson
Oil Type	SAE 20W-50 (Harley-Davidson Formula+ or equivalent API SG+)	H-D Service Manual
Oil Capacity (with filter)	4.5 quarts (144 oz) — trike-modified oiling system	H-D Trike Service Manual
Oil Capacity (no filter)	4.0 quarts (128 oz)	H-D Trike 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 (10mm Allen)	H-D Service Manual
Drain Plug Torque	14-18 ft-lbs	H-D Service Manual
Drain Plug Washer	Copper crush washer, 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 (trike models require more frequent service)	H-D Trike Owner Manual

Difficulty and Time Estimate

Difficulty Level: Intermediate (2 out of 5) — trike access requires more planning, heavier bike, jack placement is critical
Estimated Time: 60-75 minutes (first-timer: 75-90 min)
Best Done: On a warm engine, with proper trike-rated jack or lift, in a spacious area

Complete Tool List

Tool	Size/Type	Purpose
Allen/hex wrench	3/8 inch (10mm)	Remove drain plug
Torque wrench	10-25 ft-lb range, 3/8 inch drive	Torque drain plug
Ratchet	3/8 inch drive	General use
Extension	3/8 inch drive, 6 inch	Reach around trike rear end
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 with long narrow spout	Add new oil
New oil filter	OEM 63731-99A or aftermarket equivalent	Replace old filter
Drain plug washer	Copper crush washer (new, each change)	Seal drain plug
Clean rags/shop towels	Several	Cleanup
Ground cover	Large cardboard or mat	Protect floor
Trike-rated jack or lift	Minimum 1,500 lb capacity rated	Elevate trike safely (standard lifts may not fit)
Flashlight	—	Under-trike illumination
Work light	LED or similar	Illuminate service area

Step-by-Step Instructions

Step 1: Warm the Engine

Start the Tri Glide Ultra and let it run for 5-10 minutes. The M-114 engine in a trike configuration works harder due to the additional weight (approximately 1,200 lbs total). Warm oil drains more completely and carries suspended contaminants better. Park on a completely level surface.

Step 2: Position the Trike Safely

The Tri Glide Ultra is significantly wider and heavier than a two-wheel motorcycle. Use a trike-rated floor jack, motorcycle lift rated for trikes, or the OEM Harley-Davidson trike jack fixture. Do NOT use a standard two-wheel motorcycle lift — it is not designed for the trike rear axle width and weight distribution.

Critical: The Tri Glide must be elevated carefully. The rear differential and dual wheels change the lifting points. Refer to your trike owner's manual for proper jack placement locations.

Step 3: Remove the Oil Fill Cap

Remove the oil fill cap/dipstick from the right side oil tank. On the Tri Glide, access is similar to the standard Touring models but may be partially obstructed by the trunk and rear end configuration. Remove the seat for full access if necessary.

Step 4: Position the Drain Pan

Place a minimum 6-quart oil drain pan beneath the drain plug. The Tri Glide may require a 6-inch extension to reach the drain plug from the side due to the trike rear frame and differential housing.

Step 5: Remove the Drain Plug

Using a 3/8 inch hex wrench (possibly with an extension for clearance), loosen the drain plug counterclockwise. Remove by hand — be ready for warm oil flow.

Warning: Oil may be hot. The trike engine runs under more load and may be hotter than a two-wheel bike. Wear gloves and eye protection.

Step 6: Drain All the Oil

Allow full drainage — 10-15 minutes. Inspect the drain plug and oil for unusual material. The M-114 in a trike application experiences higher sustained loads, making clean oil especially important.

Step 7: Replace the Drain Plug Washer

Remove the old copper crush washer and replace with a new one. Never reuse — single-use sealing component.

Step 8: Reinstall the Drain Plug

Clean the threads and seating surface. Install with the new washer, hand-tighten, then torque to 14-18 ft-lbs.

Do NOT over-torque. Stripping the oil tank threads on a Tri Glide is especially problematic given the trike's weight and limited access for repair.

Step 9: Remove the Old Oil Filter

Locate the oil filter on the oil tank (typically bottom/side area). Access may be tighter on the Tri Glide due to the frame modifications for the rear differential. Position catch rags. Use a filter wrench to loosen, then spin off by hand.

Step 10: Prepare the New Filter

Apply clean 20W-50 motorcycle oil to the new filter rubber gasket
Verify the old gasket was fully removed from the mounting surface
Do NOT pre-fill — will spill when installed

Step 11: Install the New Oil Filter

Thread by hand. When the gasket contacts the seat, tighten an additional 3/4 turn by hand.

Hand-tighten only.

Step 12: Add New Oil

Pour approximately 4.0 quarts of SAE 20W-50 motorcycle oil into the fill port. Use H-D Formula+ or equivalent API SG+ rated oil with JASO MA/MA2 certification.

Trike Note: The Tri Glide may hold slightly more oil than standard Touring models due to the modified oiling system for the trike frame. Use 4.0 quarts as the starting fill amount and adjust based on the dipstick reading.

Step 13: Verify the Oil Level

Rest fill cap on threads without tightening
Start the engine and idle for 2-3 minutes
Shut off and wait 1-2 minutes
Check the dipstick (trike perfectly level) — between Add and Full marks
Add oil in 1/4 cup increments if needed, rechecking
Tighten fill cap securely when correct

Step 14: Final Checks and Safety

Check for leaks at drain plug and oil filter from multiple angles
Check any oil that may have dripped on the rear differential housing or driveshaft (wipe clean)
Inspect the rear differential oil level as a bonus check (different fluid — gear oil, not engine oil)
Wipe any spilled oil from frame, fenders, or chrome
Reset the Tri Glide maintenance reminder on the infotainment display if equipped
Properly dispose of used oil and filter (see below)
Record this service in your Tri Glide maintenance log

Tips, Warnings and Common Mistakes

Helpful Tips

Trike-specific oil changes: The Tri Glide puts significantly more load on the engine. More frequent oil changes (every 3,000-5,000 miles) are recommended, especially for long-distance touring.
Jack placement is critical: The Tri Glide center of gravity and weight distribution differ substantially from two-wheel motorcycles. Always use trike-rated lifting equipment.
Bonus check: While you are under there, check the rear differential gear oil level — the Tri Glide has a separate lubricated differential that requires periodic maintenance.
Full synthetic consideration: Many Tri Glide owners switch to full synthetic 20W-50 for better protection under the higher load conditions of trike operation.

Warnings

NEVER use automotive oils — the Tri Glide wet clutch requires JASO MA/MA2 motorcycle oil.
Do NOT use a two-wheel motorcycle lift — the Tri Glide rear end will NOT fit and the lift may tip.
Do NOT over-torque the drain plug — oil tank thread repair on a Tri Glide requires removing the rear end assembly.

Common Mistakes to Avoid

Mistake	Consequence	How to Avoid
Using two-wheel lift for trike	Lift failure, trike damage or injury	Use trike-rated lift only
Over-torquing drain plug	Expensive repair requiring rear-end removal	14-18 ft-lbs with torque wrench
Reusing drain washer	Oil leak	Replace every change
Using car oil	Clutch slippage	JASO MA/MA2 required
Not checking oil level after fill	Engine damage	Start, wait, recheck dipstick
Checking differential as engine oil	Mixing gear oil and engine oil	Oil fill is separate from differential fill
Double-gasketing filter	Major oil leak	Verify old gasket removed

Oil Disposal

Never pour used oil down drains, into trash, or on the ground.

Transfer to a clean sealed container
Drop off at: AutoZone, O'Reilly Auto Parts, Advance Auto Parts, NAPA (all accept oil free)
Include old oil filter
Municipal recycling and hazardous waste facilities also accept
Never mix with gear oil or other fluids

Verification Notes for 2025 Model Year

Spec	Known Value	Notes
Oil capacity	4.5 qts (with filter)	Trike-modified oiling system, verify for 2025
Oil type	SAE 20W-50	Standard for M-114 Trike
Drain plug tool	3/8 inch hex (10mm Allen)	Standard Touring/Trike
Drain plug torque	14-18 ft-lbs	Verify in owner manual
Oil filter	63731-99A / KN-170	Standard Harley filter
Oil fill location	Right side oil tank	Similar to Touring models
Service interval	5,000 miles	Trike models — more frequent than two-wheel
Jack points	Trike-specific — NOT two-wheel lift	Check trike owner manual carefully
Differential oil	Separate gear oil — different system	Not part of engine oil change

To verify: Consult your 2025 Tri Glide Ultra owner's manual, available in print or via the Harley-Davidson app. An authorized H-D Trike dealer has full service specifications for the Tri Glide chassis.

Guide prepared based on Milwaukee-Eight 114 Tri Glide service manual specifications and Harley-Davidson OEM recommendations. Always verify against your specific owner's manual before performing maintenance.