Technical information

This page provides technical guides, tips and explanations for common repairs and modifications
to your 1964–1973 Mustang. Whether you're working on the transmission, steering, brakes or bodywork –
we'll show you which parts you need and how to carry out the work correctly.

Engine Oil

For classic inline-six and V8 engines, we recommend using a mineral engine oil with a viscosity of 15W40 or 20W50.
For vehicles driven only during the summer or engines with some wear, 20W50 is recommended. If the vehicle is also driven during winter
and the engine is still in good condition, 15W40 is the better choice.
It is important to use oil with an API SE or SF classification, as modern additives may damage older seals and materials
and often contain too little zinc for proper lubrication of the flat tappets on the camshaft.

Recommended Oils:

MILLERS CLASSIC SPORT 20W50 5L (API SJ with zinc additive)
GULF CLASSIC 20W50 5L (API SF)
ORLEN Universal 15W40 5L (API SF)

Recommended engine oil capacities for original Ford Mustang oil pans:

Oil Filter

All Ford Mustang inline-six and V8 engines use the same oil filter.
We recommend filling the oil filter with a small amount of engine oil before installation
to ensure oil pressure builds immediately when the engine is started.

Recommended Models:

Motorcraft FL-1A
Autolite FL1 Replacement
WIX 51515

Automatic Transmission Fluid C4 and C6

Ford ATF Type F
The fluid is available in 1-liter containers and 4-liter containers.

Important:
Check the automatic transmission fluid level with the engine running, at operating temperature and the selector in position P.

Changing Automatic Transmission Fluid (C4 & C6)

The original automatic transmissions do not have a drain plug. During every fluid change, we recommend removing the transmission oil pan
to replace or clean the filter and remove clutch material deposits from the pan.
The torque converter should also be drained. Remove the inspection cover
at the bottom of the bellhousing and rotate the engine until the drain plug
of the torque converter is positioned at the bottom.
Drain the transmission fluid from the converter. When refilling the transmission,
the converter will refill automatically.
To refill the transmission, first add approximately 3 liters of ATF. Start the engine,
let it idle, and continue filling the transmission with the engine running.
Check the dipstick repeatedly until the fluid reaches the FULL mark.

Manual Transmission Oil T10, Toploader, T5

Checking the Fluid Level:
The transmission is considered "full" when the oil reaches the bottom edge of the fill opening (you can feel it with your finger).
All manual transmissions are equipped with a drain plug to remove the old oil.
The fill and drain plugs are normally self-sealing NPT threads.

Original Ford Power Steering

Ford ATF Type F approx. 2L
The fluid is available in 1-liter containers and 4-liter containers.
Fill the power steering pump to approximately 3/4 full. Then start the engine and continue filling while the engine is running.
Turn the steering wheel fully left and right several times to bleed the system. Continue adding fluid until the dipstick indicates FULL.

Borgeson Power Steering

DEXRON III approx. 2L

Ford Steering Gearbox

Liqui Moly LM47 approx. 100–200 g

Rear Axle 7.25", 8" and 9"

80W90 GL5 Mineral Hypoid Gear Oil

A Ford XL-3 (120 ml) friction modifier is required for clutch-type limited-slip differentials, Trac-Lok and Equa-Lok differentials.

7.25" approx. 1.4–1.7 liters (used on inline-six engines, 4-lug wheel pattern. V8 models use a 5-lug wheel pattern.)

8" approx. 1.9–2.0 liters (commonly used with the 289 and 302 engines, occasionally with the 351)

9" approx. 2.3–2.5 liters (commonly used with the 351 and always with the 390 and 428)

How to identify the 7.25", 8" and 9" rear differentials:
The 9" differential requires a box-end wrench to remove the two lower nuts.
On the 8" differential, all nuts can be reached using a socket and extension.
The center section can be removed from both the 8" and 9" rear axles.
The 7.25" rear axle has a removable rear cover. The differential cannot be removed from the axle housing.

Checking the Oil Level:
The differential is considered "full" when the oil reaches the bottom edge of the fill opening (you can feel it with your finger).

The original differentials do not have a drain plug. We recommend removing the center section from the rear axle (8" and 9" differentials only), as this is the only way to completely remove sludge and deposits from the axle housing.

Coolant

Recommended Coolant for Classic Mustang Cooling Systems

For original or largely original cooling systems, we recommend using a silicate-containing hybrid coolant meeting VW TL 774-C/G11 or equivalent G48 specifications, regardless of whether your Mustang is equipped with a brass/copper radiator or an aluminum radiator.

These coolants are suitable for classic mixed-metal cooling systems containing cast iron, steel, aluminum, copper and brass. Even with an aluminum radiator, switching to a silicate-free or newer coolant is generally not necessary.

Suitable products include:
• Glysantin G48
• Ravenol HTC Protect MB 325.0
• Mobil Antifreeze Extra
• Ravenol TTC Protect C11
• Other coolants that clearly meet VW TL 774-C / G11 specifications and are approved for cast iron, aluminum, copper and brass cooling systems.

Alternative Modern Coolant Technology

If the cooling system has been completely drained and thoroughly cleaned, modern Si-OAT coolants meeting VW TL 774-G / G12++ specifications may also be used, provided the product is suitable for all materials used in the cooling system.

Examples include:
• Glysantin G40
• Valvoline G12++
• Other coolants clearly specified as VW TL 774-G / G12++ Si-OAT coolants.

However, switching to G12++ is not mandatory simply because an aluminum radiator is installed. Always follow the recommendations of the coolant manufacturer and, where applicable, the radiator manufacturer rather than relying solely on the radiator material.


Which Water Should Be Used for Mixing?

Coolant concentrate should preferably be mixed with demineralized or distilled water. Depending on the local water hardness and mineral content, tap water can cause lime scale and other deposits.
Tap water can be used for initial flushing. For the final rinse and the final refill, we recommend using demineralized or distilled water.

Mixing Ratio

The recommended mixing ratio is:
50% coolant concentrate and 50% water.
Premixed coolants must not be diluted further.
Keep in mind that after flushing, water often remains inside the engine block and heater core. In this case, calculate the amount of concentrate based on the total cooling system capacity to achieve an overall mixture of approximately 50:50.

Coolant Compatibility

Different coolant technologies should not be mixed. The same color or an ethylene glycol base does not automatically mean that the corrosion inhibitors are compatible.
Small accidental mixtures usually do not cause immediate damage. However, they may reduce corrosion protection, shorten coolant life and affect the recommended service interval.
If the previously used coolant is unknown, or when changing coolant type, the cooling system should always be completely drained and thoroughly flushed before refilling.

Important:
The exact capacities may vary depending on radiator size, hoses, whether a heater core is installed, thermostat type, and other components.

Cooling System Filling Procedure:

- Fill the radiator to approximately 1" (2.54 cm) below the filler neck. Do not install the radiator cap yet.
- Start the engine and allow it to reach operating temperature.
- Once the thermostat opens, top up the coolant to approximately 1" (2.54 cm) below the filler neck again, then install the radiator cap.
- Allow the engine to cool completely and recheck the coolant level.
- The correct coolant level is always approximately 1" (2.54 cm) below the top of the radiator. The upper section of the radiator serves as the expansion chamber.

Thermostat

- 180°F (82°C)
- 195°F (90°C)

! Do not use a 160°F (71°C) thermostat. The engine will run too cool, resulting in increased wear, higher fuel consumption and sludge formation inside the engine.

Radiator Cap

13 PSI

Brake Fluid

DOT 3 (approx. 1 liter)

Ignition Timing

- With an electronic ignition system such as the Pertronix Ignitor: 10–12° BTDC at idle with the vacuum advance disconnected.
- With a conventional breaker-point ignition: 8–10° BTDC at idle.
- Maximum mechanical advance: 34–36° at approximately 3,000 RPM.
- Maximum combined mechanical and vacuum advance: approximately 50°.

Wheel Alignment

Camber / Toe / Caster

On 1965 and 1966 Mustangs, camber and caster are adjusted using shims.
These are alignment shims installed between the upper control arm and the shock tower.

Shims are available in three different thicknesses.

Starting in 1967, caster is adjusted using the threaded adjustment at the front of the strut rod.
Camber is adjusted using the eccentric cam on the lower control arm.
Always adjust the suspension in the following order: Camber first, then caster, and finally toe.

The specifications listed in the original Ford shop manual were intended for bias-ply tires.
For modern radial tires, the following settings provide significantly better handling (with or without the Shelby Drop).

Normal Street Driving

- Total toe-in: 3 mm (measured at the tire tread)
- Equivalent to approximately 20 minutes of toe on 14" or 15" wheels
- Camber: 0°
- Caster: +2.5°


Sporty Driving

- Total toe-in: 2 mm (measured at the tire tread)
- Equivalent to approximately 12 minutes of toe on 14" or 15" wheels
- Camber: −0.5°
- Caster: +5°

Mustang Wheel Alignment Video

With this technical information, we aim to help you keep your Mustang original, reliable and safe on the road.
Happy wrenching!

All information is provided without guarantee. We accept no liability for the accuracy or completeness of the information provided above.