Oil Tanks for Big Twin 1936-1939
Select variant:

fits Knucklehead, Big Twin Flatheads 1938-1939; chrome-plated; drain plug: 5/8”-18 UNF; Fitting Thread: 9/16“-24; replaces OEM HD 3503-38


fits Knucklehead 1936; black; drain plug: 5/8”-18 UNF; Fitting Thread: 3/8“-24 / 1/2”-20; replaces OEM HD 3503-36

fits Knucklehead, Big Twin Flatheads 1937; black; drain plug: 3/4”-20 UNF; replaces OEM HD 3503-36

fits Knucklehead, Big Twin Flatheads 1938-1939; black; drain plug: 5/8”-18 UNF; Fitting Thread: 9/16“-24; replaces OEM HD 3503-38
Price and stock:
Item №
50-068
Price incl. VAT
386.67 €
Available
4
Ready for immediate delivery from our Würzburg, Germany warehouse
The price includes 61.74 € German VAT.
- Oil tank
- fits Knucklehead, Big Twin Flatheads 1938-1939
- sheet steel, chrome-plated
- drain plug: 5/8”-18 UNF
- filler spout: 1-1/4”-20
- Fitting Thread: 9/16“-24
- replaces Harley-Davidson part number HD 3503-38
- gross weight: 3.4 kg
Accurate reproductions of the distinctive horseshoe-style oil tanks as used on Knuckleheads and Big Twin Flatheads 1936-1939. All stampings and fittings precisely match the original counterparts. You will need the exact oil lines for installation. Although these tanks are correct only for one or two model years, they will fit all Big Twin frames 1936-1964 for custom applications.
Spare parts:

Strange Bird Repair Brackets Horseshoe Oil Tank
The left side lower rear mounting bracket, where chainguard and inner tin primary are attached, is typically rotten on most original Horseshoe oil tanks. These weld-on repair pieces come in handy to restore the bracket to its original state.

OEM Style Oil Tank Filler Cap and Gauge 1936-1964
Accurate reproductions of the factory filler caps and dip sticks as used for stock Horseshoe style oil tanks.
Accessories:

50-076
Drain valve by stahlbus; fits OEM horseshoe oil tanks 1938→, 45" →1973, FLT 1980-early 1981, XLCH →1973, XLCR 1977, Sportster 1979-1981; steel / aluminum; thread: 5/8”-18; with valve, a copper seal, 40 cm hose, a protective cover, detailed instructions; Germany; NOTE: On 1958-1964 swingarm frames space under the oil tank is limited. Pls check before trying to mount the valve.; gross weight: 140 g

Fittings for Rubber Oil Lines
WR style, one-piece solution when you want to run flexible oil lines. Can be used on all oil tanks, oil pumps and crankcases with 9/16"-24 fittings.

Baseplates for Horseshoe Oil Tanks

Oil Tank Mounting Kits for Big Twin 1936-1964
Reproduction of all original screws, nuts and spacers to mount oil tanks of 1936–1964 Big Twin models.
See also:

Bates BattBoy HM5
Modern gel or Li-Ion batteries offer a significant advantage - they are leak-proof. Those who ever experienced spilled acid in their horseshoe oil tanks will highly appreciate this fact. On the other hand, owners of classic bikes do like the looks of their original energy store and the corresponding cover and mounts. With a Bates BattBoy Battery Box you can have the best of both worlds, because what looks like a period type HM5 6V accumulator on the outside can house a safe, modern battery within. Just hook it with two eyelet wires to the terminals on the bottom of the lid and you are all set. Perfect for 6 to 12 volts electrical system conversions, too. When using suitable Antigravity versions you even have some storage room left for a few small spare parts, safety vest, Cuban cigars, etc. Ain't this one heck of a cool solution for an old problem?

Battery Top Covers Big Twin 1936-1964
Reproductions of the 6 V battery top covers as used on 1936-1964 Big Twin models.

PanAm Oil Slide
Oil change without a mess! This rubberized aluminum alloy sheet allows you to form an individual funnel or trough to direct your waste oil from the hard-to-reach oil tank drain hole or oil filter plate to any suitable container. Of course, you can also use it to fill fresh oil into your tank. Tapered at one end so it can be shaped to reach tight spots. You can reshape and use it a thousand times and on different bikes. With suspension eye so you can hang it up for drip-off. Easy to clean.

Cannonball LION Battery Boxes
Our electric start system just got even more stealthy....

PanAm Oil/Ignition Shut-Off Valves
Pre-TwinCam engines have a spring loaded ball check valve to prevent the engine oil from seeping down to the crankcase. These check valves don’t last forever. If you try to start your engine after a lengthy period of inactivity (e.g. winter), the oil in the crank case gets forcefully ejected via the breather. Creating an ungodly mess on your garage floor....

6V Acid Type Batteries 1929-1964
The legendary battery as used by the Motor Company for decades. These accurate reproductions exactly fit into your stock horseshoe oil tanks or battery trays and have the poles in the correct positions.

Hex Oil Tank Filler Cap and Gauge 1936-1964
Custom oil tank filler cap and dipstick with chrome-plated hex head. Fits all stock H-D horseshoe oil tanks or similar aftermarket oil tanks.

PanAm Oil SAE 50
Our traditional single grade lubricant for engine and transmission for heavy thermal and shear loads. Complies with H-D recommendations up to 1984 for Big Twins and Sportsters up to 1981. This high performance lubricant complies with API CF.

12V Acid Type Battery for Horseshoe Oil Tanks
Custom battery which fits into your stock horseshoe oil tank or 45” battery tray. It is shorter than the original 6 V battery, therefore the use of standard mounting components requires a spacing block or extension.

Have any questions?
Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: service@wwag.com