BMW X3 (F25) Service & Repair Manual: Checking transmission fluid level

4.0 CHECKING TRANSMISSION FLUID LEVEL

Due to the substantial expansion of transmission fluid when heated it is only possible to measure the oil level correctly at specified oil temperatures (after driving a distance of about 12 mi./20 km).

ZF 3HP AND 4HP

Due to the substantial expansion of transmission fluid when heated it is only possible to measure the oil level correctly at specified oil temperatures (after driving a distance of about 12 mi./20 km).

A5S 560Z, A5S440Z, GA6HP19Z, GA6HP26Z, GA6HP26Z, GA8HP70Z A5S325Z, A5S 310Z

All 5, 6 and 8 speed transmissions require the fluid to be checked when fluid temperature is between 30-50º Celsius using DIS Plus or GT1. Do not check fluid level after temperature has exceeded 50º Celsius.

A4S 270R, A4S 310R, A5S 360R, GA6L45R

Fluid Level Checking Procedure for all Transmissions without a Dipstick:

1. The transmission temperature must be between 30ºC and 50ºC before checking can begin. Use the DIS or the MODIC to determine the transmission temperature.

2. The vehicle must be level and without load. With the engine running, switch on the air conditioning. This will increase the idle speed and ensure that all oil passages in the transmission are filled with oil.

3. Step on the brake firmly, apply parking brake fully and move the selector lever through each gear position, pausing briefly in each gear.

4. With the engine running and the selector lever in Park position, remove the filler plug located on the transmission (see illustration for location). If a small stream of oil runs out, the fluid level is correct.

5. If no oil runs out when the filler plug is removed, the fluid level is too low. Add oil until it starts to overflow.

6. With the engine running, reinstall the oil filler plug and tighten.

8HP TRANSMISSION: FLUID LOSS FROM COOLER LINE CONNECTIONS - FROM SERVICE BULLETIN SI B24 02 15 (6/2015)

Applies to the following models with N20, N26, or N55 engine and 8HP transmission:

• E84 (X1)
• E89 (Z4)
• F22 (2 Series Coupe)
• F23 (2 Series Convertible)
• F30 (3 Series Sedan)
• F31 (3 Series Sports Wagon)
• F32 (4 Series Coupe)
• F33 (4 Series Convertible)
• F34 (3 Series Gran Turismo)
• F36 (4 Series Gran Coupe)

Situation:

There is a transmission fluid leak in the area around the oil cooler lines (on the transmission side).

Cause: Damaged o-rings due to unfavorable cooling line connection tolerances.

Procedure: Verify that the transmission fluid leak originates from the cooling lines area.

If so, replace the o-rings and the cooling lines.

Only replacing the o-rings may cause a repeat failure.

E70, E71, F25: OIL LEAK FROM TRANSFER CASE - FROM SERVICE BULLETIN SI B24 01 13 (3/2013)

Applies to the following models:

• E70
• E71
• F25

Situation: Oil is leaking from the transmission area, or oil seepage is noticed from the transmission/transfer case area during a service.

Cause: The leak can be misdiagnosed as a transmission fluid leak from either the mechatronics sleeve or transmission oil pan. The leak is actually coming from the transfer case (input or output shaft seal).

Procedure: Before attempting to perform any repairs, check the fluid level in both the transmission and transfer case.

If the level is low in the transfer case, repair as necessary.