Harley-Davidson · Harley-Davidson flathead, recirculating (U/UL, W/WL/WLA, G Servi-Car 1937-1973)

W / WL / WLD / WR 45

Library entry covers 1937-1952

31 factory 39 guideline

Published source

TM 9-879 Motorcycle, Solo (Harley-Davidson Model WLA), War Department, 1943 (Lubrication Guide fig. 10 and 1,000-mile maintenance)

Factory workshop manual. Covers 1942-1943 (WLA military WL).

Open the source

70 items for a 1940 model, grouped by interval the way a factory chart is laid out.

How this bike is built (what the schedule is based on)

Engine cycle: Four-stroke
Engine lubrication: Dry sump (separate oil tank)
Oil filtration: None (no filter)
Valve gear: Side valve (flathead)
Ignition: Battery and coil with contact points
Charging: DC generator with regulator
Battery: Wet cell (flooded lead-acid, needs topping up)
Fuel system: Single carburetor
Cooling: Air / oil cooled
Primary drive: Chain fed by engine oil / breather (no separate oil change)
Gearbox oil: Separate gearbox oil
Clutch control: Foot clutch / hand shift
Final drive: Chain
Front suspension: Springer fork
Rear suspension: Rigid (hardtail)
Front brake: Drum (or band / stirrup)
Rear brake: Drum (or band / belt rim)
Wheels: Spoked, tubed
Sidecar: No sidecar

Maintenance schedule

1940 Harley-Davidson W / WL / WLD / WR 45

On the road: every 200 mi

1 item

Check engine oil level

Pre-ride / on the road

Guideline

Each fuel stop on old machines. Dry sump: check the tank hot, engine idling or just stopped, per your manual.

On the road: every 300 mi

3 items

Check lights, horn, brake light switches

Pre-ride / on the road

Guideline
Check tire pressures

Pre-ride / on the road

Guideline
Lubricate drive chain

Pre-ride / on the road

Guideline

Lube warm, ideally at the end of the riding day so it soaks in overnight. Sooner after rain.

On the road: every 500 mi

2 items

Grease girder / springer fork links

Pre-ride / on the road

Guideline

Grease gun on every nipple until clean grease shows. Touring days add up fast.
Walk-around: check nuts and bolts for vibration loosening

Pre-ride / on the road

Guideline

Old machines shake things loose: exhaust nuts, mudguard stays, footrests, tank mounts, battery strap.

On the road: every 600 mi

1 item

Check chain slack and rear wheel alignment

Pre-ride / on the road

Guideline

On the road: every 1,000 mi

1 item

Check road kit: plugs, points file, master link, tube patches, wire, tape

Pre-ride / on the road

Guideline

Every 250 mi

8 items

Clean / inspect air filter

Fuel and air

Factory

Manual: Air cleaner: drain, clean and refill oil cup. Factory: every 250 miles; inspect daily, p.32
Adjust clutch pushrod / clutch adjuster

Primary and gearbox

Factory

Manual: Clutch release bearing: grease. Factory: CG grease every 250 miles, p.31
Check gearbox oil level

Primary and gearbox

Factory

Manual: Check oil level in transmission case. Factory: add engine oil to filler opening level every 250 miles, p.33
Check springer rocker stud play and spring condition

Front end

Factory

Manual: Fork rocker plate and fork spring rods: grease. Factory: CG grease every 250 miles, p.31
Check footrests, pegs, rear brake and gear lever pivots

Rear suspension and frame

Factory

Manual: Brake pedal shaft and brake crossover shaft: grease. Factory: CG grease every 250 miles, p.31
Grease saddle pivot, check saddle springs / seat post

Rear suspension and frame

Factory

Manual: Saddle arm and saddle post: grease. Factory: CG grease every 250 miles, p.31
Lubricate brake cam spindles, check linings and drums

Brakes

Factory

Manual: Brake camshaft and brake cover bearing: grease. Factory: CG grease every 250 miles, front and rear, p.31
Lubricate control cables and lever pivots

Controls and cables

Factory

Manual: Brake hand lever: oil. Factory: engine oil every 250 miles, p.31

Every 500 mi

1 item

Check wheel bearings for play

Wheels and tires

Factory

Manual: Wheel bearings: grease. Factory: WB grease every 500 miles, 1/8 ounce per hub, p.31-32

Every 1,000 mi or 6 months

2 items

Lubricate manual advance / retard control and cable

Ignition and electrics

Guideline
Adjust foot clutch and hand-shift linkage, lubricate pivots

Primary and gearbox

Guideline

Every 1,000 mi

19 items

Change engine oil

Engine

Factory

Manual: Drain oil tank and refill with fresh engine oil. Factory: every 1,000 miles; oftener in dusty or winter service, p.32
Check and adjust valve clearances

Engine

Factory

Manual: Valve tappet clearance, engine cold. Factory: 1,000-mile item 36: intake .004-.005, exhaust .006-.007 in., p.52
Check engine mounting bolts and plates

Engine

Factory

Manual: Engine mountings: inspect and tighten. Factory: 1,000-mile maintenance item 32, p.52
Compression test (or leak-down)

Engine

Factory

Manual: Compression test. Factory: 1,000-mile maintenance item 17, p.49
Inspect, clean and gap spark plugs

Engine

Factory

Manual: Spark plugs: clean, inspect, gap 0.025-0.030 in.. Factory: 1,000-mile maintenance item 26, p.51
Clean fuel tap filter / sediment bowl

Fuel and air

Factory

Manual: Fuel strainer: clean; drain carburetor bowl. Factory: 1,000-mile maintenance item 42, p.53
Remove and wash air cleaner filter units

Fuel and air

Factory

Factory: every 1,000 miles (oftener if necessary), p.32
Check battery electrolyte, top up with distilled water

Ignition and electrics

Factory

Manual: Battery: specific gravity, electrolyte level. Factory: 1,000-mile maintenance item 21; also weekly service, p.50
Clean and gap contact breaker points, oil cam felt

Ignition and electrics

Factory

Manual: Timer: inspect, dress breaker points, gap 0.022 in.. Factory: 1,000-mile maintenance item 25, p.50-51
Inspect generator brushes and commutator

Ignition and electrics

Factory

Manual: Generator commutator and mounting: inspect. Factory: 1,000-mile maintenance item 24, p.50
Adjust clutch free play, lubricate cable and lever pivot

Primary and gearbox

Factory

Manual: Clutch pedal and linkage: check free travel, lubricate. Factory: 1,000-mile maintenance item 46, p.54
Change gearbox oil

Primary and gearbox

Factory

Manual: Drain and refill transmission. Factory: every 1,000 miles, 3/4 pint engine oil, p.33
Check / adjust primary chain

Primary and gearbox

Factory

Manual: Primary drive: check chain slack and lubrication. Factory: 1,000-mile maintenance item 45, 1/2-inch deflection, p.53-54
Clean drive chain thoroughly (remove and soak, re-lube)

Final drive

Factory

Manual: Rear drive chain: remove, wash, soak in SAE 10 oil. Factory: every 1,000-mile period; front chain excepted, p.33
Check steering head bearing adjustment

Front end

Factory

Manual: Steering head and fork stem: check play. Factory: 1,000-mile maintenance item 52, p.54-55
Adjust front drum brake

Brakes

Factory

Manual: Front brake: adjust, 1/4 hand lever free travel. Factory: 1,000-mile maintenance item 65, p.55-56
Adjust rear drum brake and rod / cable linkage

Brakes

Factory

Manual: Rear brake and linkage: adjust, 1-inch pedal free travel. Factory: 1,000-mile maintenance item 75, p.57
Check spoke tension and wheel true

Wheels and tires

Factory

Manual: Front and rear wheel spokes and alinement. Factory: 1,000-mile maintenance items 66 and 70, p.56-57
Inspect tire tread, sidewalls and date codes

Wheels and tires

Factory

Manual: Tires: gage and inspect, 18 lb front, 20 lb rear. Factory: 1,000-mile maintenance item 69, p.56-57

Every 2,000 mi or 12 months

1 item

Check primary chain oil supply (breather / pump feed)

Primary and gearbox

Guideline

Several pre-war and early post-war designs oil the primary chain from engine oil. Check the feed adjuster or breather path per your year's manual.

Every 3,000 mi or 12 months

7 items

Check throttle cable(s) free play and return

Fuel and air

Guideline
Check / set ignition timing

Ignition and electrics

Guideline
Check generator drive belt or chain

Ignition and electrics

Guideline
Check chain guard, chain oiler (if fitted), rear chain case

Final drive

Guideline
Inspect chain and sprockets for wear (measure stretch)

Final drive

Guideline
Check steering damper (friction or hydraulic)

Front end

Guideline
Grease and check center / side stand and springs

Rear suspension and frame

Guideline

Every 4,000 mi or 12 months

1 item

Replace spark plugs

Engine

Guideline

Every 5,000 mi or 2 years

2 items

Check cylinder head bolt torque

Engine

Guideline

Air-cooled iron and alloy engines can lose head bolt tension; follow your manual's sequence and whether it is done hot or cold.
Flush oil tank and clean tank screen

Engine

Guideline

Every 6,000 mi or 12 months

3 items

Clean carburetor float bowl(s), check float level and jets

Fuel and air

Guideline

Ethanol fuel varnishes old carbs quickly in storage.
Check charging voltage and regulator / cut-out

Ignition and electrics

Guideline
Lubricate speedometer / tachometer cables, check drive

Controls and cables

Guideline

A dry speedo cable whips the needle and eventually kills the instrument.

Every 6,000 mi or 2 years

2 items

Check engine breather and oil return

Engine

Guideline
Lubricate and check automatic advance unit

Ignition and electrics

Guideline

Every 6,000 mi

2 items

Oil / check generator bearings (where an oiler is fitted)

Ignition and electrics

Factory

Manual: Generator commutator end bearing: hand-pack grease. Factory: WB grease, 6 = 6,000 miles on guide, p.31
Repack / replace wheel bearings

Wheels and tires

Factory

Manual: Front wheel bearings: clean and repack. Factory: each sixth 1,000-mile maintenance service, p.56

Every 8,000 mi or 3 years

1 item

Decarbonize head, grind / lap valves (top-end decoke)

Engine

Guideline

Period practice. Leaded-era valve seats may need hardened seats for unleaded fuel.

Every 10,000 mi

1 item

Replace chain and sprockets (wear based)

Final drive

Guideline

Every 12,000 mi or 3 years

1 item

Replace points and condenser

Ignition and electrics

Guideline

Every 15,000 mi or 5 years

1 item

Inspect clutch plates and springs

Primary and gearbox

Guideline

Every 15,000 mi

1 item

Replace brake linings / skim drums (wear based)

Brakes

Guideline

Every 50,000 mi

1 item

Repack / replace steering head bearings

Front end

Factory

Manual: Steering head bearings: repack. Factory: every 50,000 miles or when fork removed, p.32

Every 6 months

1 item

Clean battery terminals, check charge and strap

Ignition and electrics

Guideline

Every 12 months

1 item

Check speedometer / odometer against a known distance

Controls and cables

Guideline

Old speedos drift with tire size and drive wear. Use phone GPS over a measured 10 miles / km.

Every 2 years

3 items

Inspect fuel tank for rust, sealer failure, leaks

Fuel and air

Guideline
Inspect wiring, bullet connectors and ground points

Ignition and electrics

Guideline
Inspect frame, welds and lugs for cracks

Rear suspension and frame

Guideline

Every 4 years

1 item

Replace fuel lines

Fuel and air

Guideline

Old rubber and modern ethanol fuel do not mix well.

Every 6 years

2 items

Replace inner tubes and rim tape with tires

Wheels and tires

Guideline
Replace tires on age (regardless of tread)

Wheels and tires

Guideline

Guideline lines: Intervals here are general guidelines for the machine's era and layout, compiled for this app. They are not factory manual figures. Check your workshop manual, and edit any interval in the bike's Schedule tab.