The automatic transmission is a component comprised of many precision manufactured parts. The fluid level should be checked and, where applicable, changed during the recommended service intervals. If nothing else, inspect the transmission for potential fluid seepage at gaskets and seals and repair in a timely manner. Occasionally check the area under which the vehicle is parked to see if there are any fluid spills.
Running a transmission low on fluid could have severe mechanical consequences, which timely repairs and maintenance will help to avoid. The cost of maintaining a transmission is less than 1 / 10 of the cost of replacing it.
If the transmission is in need of repair, check with a local dealer about the cost of an exchange transmission. These transmissions usually offer a reasonable warranty, and the failed transmission is given partial credit toward the replacement transmission as a rebuildable core.
The other advantage of installing an exchange transmission is the time savings. The transmission unit is shipped complete and ready to install. Otherwise the failed transmission must be disassembled, diagnosed, and the failed parts ordered, and when they arrive, the transmission is then assembled.
Due to the need for special equipment, its complexity, and the replacement cost of an automatic transmission, it may be wise to have a knowledgeable BMW service facility perform service and routine checks to the transmission on models not equipped with a dipstick.
Servicing an automatic transmission requires the removal of the sump pan(s), which, without the proper equipment are susceptible to messy fluid spills.
Drain, Filter Service & Refill
Automatic transmissions rely on many precision manufactured components, such as check valves, hydraulic pumps, hydraulic valves and the valve body, and use friction materials similar to a brake shoe or clutch disk for gear engagement.
Because the transmission fluid is exposed to high operating temperatures, and wear related debris from the metal components and clutch material fibers, it is possible for dirty or contaminated transmission fluid to mask a worn component. If the fluid has not been changed regularly, the transmission can build up sludge, carbon and other wear related debris that can make a moving hydraulic component stick or assist the operation of worn components by reducing their clearance.
Use caution when changing the fluid and filter on a transmission that has not been regularly serviced and/or has high mileage. Changing the fluid and filter could result in a sudden failure or erratic operation and/or shift engagement. This usually happens because the built up contaminants that were once compensating for the internal wear have been flushed out and removed when the fluid and filter is changed.
This is not meant to discourage someone from servicing their transmission. Statistics have proven that routine maintenance pays off over the long run. However the consequences that could result from servicing a transmission which has high mileage and/or has not been maintained within the service interval guidelines may not provide the results anticipated.
If the transmission's fluid level is within specification, and the transmission is either slipping or shifting erratically, it should be examined by a BMW dealer or a transmission specialist, before servicing the transmission oil and filter.
To remove the transmission sump and replace the filter, the vehicle will need to be raised, and safely supported to remove the fluid pan and change the filter. On models without a dipstick, the vehicle must also be level, and the fluid level is checked from underneath the vehicle.
Because of the size of the oil sump, to minimize fluid spills, a transmission fluid service drain splash shield should be placed over a suitable drain pan. If a transmission fluid service drain splash shield is not available, a sturdy non metallic mortar mixing pan works well as a substitute and is available from most hardware stores.
4hp 22 And Thm-R1 Transmissions
- Raise and safely support the vehicle in a level plane. Place a suitable drain pan equipped with a transmission fluid service drain splash shield or a suitable sized drain pan under the transmission sump. Remove the dipstick on vehicles so equipped. On vehicles with locking dipsticks, tilt the top of the dipstick to unlock.
- Loosen and remove the oil filler tube from the sump pan if not equipped with a drain plug. Be ready to catch fluid as it drains.
- Remove the sump pan drain plug and catch the draining fluid.
- Note the positions of the pan holder at each bolt and loosen and remove the bolts.
- Remove the pan and gasket. Remove the screws from the filter. Note their positions. Check that the O-ring from the filter did not stick to the transmission valve body.
- Install the new filter and O-ring. Replace the screws in their original positions.
- Clean the pan and magnets. Replace the pan gasket and install the pan on the transmission. Replace the pan holders and bolts at their original positions. Torque to 53-62 inch lbs. (6-7 Nm).
- Attach the oil filler tube, if disconnected, and torque to 72 ft. lbs. (98 Nm).
- Replace the gasket or crush washer on the drain plug and torque to 11-12.5 ft. lbs. (15-17 Nm) for transmissions with a M10 drain plug or 29.5-34 ft. lbs. (40-46 Nm) for transmissions with a M18 drain plug.
- Initially fill the transmission with approximately 3.2 quarts (3.0 liters) of DEXRON® III automatic transmission fluid through the dipstick tube on vehicles with dipsticks or through the fill plug on the side of the sump for transmissions without a dipstick.
- Refer to the fluid level checking procedures in this section and top off the fluid level as necessary.
- Test drive the vehicle and check for normal operation and fluid leaks.
Symptoms of a damaged, missing, or improperly installed filter-to-valve body seal and/or gasket include:
A4s 270 R, A4s 310 R, And A5s 310 Z Transmissions
- Raise and safely support the vehicle in a level plane. Place a suitable drain pan equipped with a transmission fluid service drain splash shield or a suitable sized drain pan under the transmission sump.
- Remove the drain plug located at the corner of the transmission sump and drain the fluid into the drain pan.
- Note the location of the fasteners and brackets and remove the oil sump and gaskets. On A4S 270 R and A4S 310 R transmissions, remove both oil sumps and gaskets.
- Remove all but one of the fasteners securing the filter assembly onto the transmission valve body. Slowly begin to remove the last fastener, turning it about 3-4 complete revolutions. Carefully wiggle the filter assembly until it releases itself from the valve body and allow the additional fluid to drain, then remove the fastener and the filter.
- Inspect the filter and the valve body for any remaining gasket material and/or O-rings. Remove any residual gasket or O-ring material from the valve body, cleaning the mounting surface on the valve body as necessary.
Install the new filter using new gaskets and/or O-rings and torque as follows:
- A4S 270 R, A4S 310 R transmissions ( 5 / 16 inch fasteners): 14.75 ft. lbs. (20 Nm)
- A5S 310Z transmissions: 53 inch lbs. (6 Nm)
- Clean the sump(s), gasket mating surfaces and magnetic drain plugs thoroughly.
- Replace all drain plug crush washers, seals, gaskets and O-rings as necessary.
- On A4S 270 R and A4S 310 R transmissions, use new fasteners, or clean and install with locking compound. Use care to not overtighten. Install the sump(s) making sure all sump brackets, if equipped are in their correct positions.
Following are the torque specifications for the A4S 270 R, A4S 310 transmissions:
M14 fill plugs: 18 ft. lbs. (25 Nm)
Following are the torque specifications for the A5S 310 Z transmissions:
M10 drain plug: 11 ft. lbs. (15 Nm)
- Initially fill the transmission with the proper amount of the recommended fluid and top off as necessary Refer to the fluid level checking procedures in this section.
Initial transmission fluid fill amounts:
- Check and top off the transmission fluid as outlined in this section.
- Test drive and check for fluid leakage and normal operation.
Symptoms of a damaged, missing, or improperly installed filter-to-valve body seal and/or gasket include:
Fluid Level Check
- With the car parked on a level surface or raised and supported in a level position, remove the filler plug from the side of the transmission housing.
- If the lubricant begins to trickle out of the hole, there is enough and you need not go any further. Otherwise, carefully insert your finger (watch out for sharp threads) and check to see if the lubricant is up to the edge of the hole.
- If the fluid level needs to be topped off, add lubricant through the access hole until the level is at the edge of the hole. Refer to the filling drivetrain fluids heading in this section and top off the fluid level as necessary with the recommended fluid.
On manual transmissions, because the transmission fill access hole is on the side of the transmission, a long section of suitable hose can be routed through the right side of the engine compartment and along the side of the transmission. To do this:
- Allow the engine to cool.
- Place a suitable drain pan under the fill hole area.
- Use a fuel/oil compatible 4 foot (120 cm) length of 1 / 2 inch (12mm) hose and a suitable funnel.
- Route the hose through the right side of the engine compartment and along the side of the transmission.
- Place the end of the hose into the fill hole opening.
- Working from the engine compartment, install a suitable funnel into the hose, and pour the fluid slowly until the transmission fluid level is correct.
- Replace the filler plug, run the engine and check for leaks.
The ATF dipstick is located toward the back of the engine compartment. The dipstick has two or three notched lines. On models with three notched lines, the upper two are used as the MIN (minimum fluid level) and the MAX (maximum fluid level) notches.
When checking the transmission fluid level, the fluid temperature is critical. On transmissions equipped with a dipstick, the transmission fluid can only be checked when the fluid temperature is 175°F (80°C). The difference between the MAX (Maximum) and MIN (Minimum) marks on the dipstick is 10 ounces (0.3 liter), or less than 1 / 3 of a quart.
- Park the car on a level surface with the engine idling. Shift the transmission into Neutral and set the parking brake.
- Use a BMW scan tool or remove the transmission dipstick and use a temperature probe long enough to be capable of reading the fluid temperature via the transmission dipstick tube. Allow the fluid temperature to reach 175°F (80°C).
- If measuring the temperature through the dipstick tube, temporarily remove the probe and check the fluid level.
When checking the fluid level:
- Remove the dipstick.
- Wipe it clean and then reinsert it firmly. Some models have locking dipsticks that require the top of the dipstick to be tilted to unlock. Be sure that it has been pushed all the way in.
- Remove the dipstick again and check the fluid level while holding it horizontally. With the engine running, and the fluid at the specified temperature, the fluid level must be between the MIN (upper MIN on models with three notches) and MAX marks on the dipstick.
If the level is too high:
- Use a siphon gun to reduce the fluid level, verify that the fluid temperature is within the acceptable range and recheck the level.
If the level is too low:
- Add a small amount of DEXRON® III automatic transmission fluid through the dipstick tube. This is easily done with the aid of a funnel.
- Verify the fluid temperature is within the acceptable range and recheck the fluid level.
- Repeat the above procedures as necessary until the fluid level is within specification.
Models Without A Dipstick
As of February 1991, use of an automatic transmission fluid dipstick has been discontinued. The transmission fluid level is checked and added through an opening on the side of the sump on early THM R1 (A4S 310R) transmissions. The transmission drain and fill plugs are on the bottom of the sump on later THM R1 (A4A 310R and A4S 270R) transmissions and early ZF A5S 310Z transmissions.
The transmission drain plug is on the bottom of the sump and the fill plug is in the transmission casting on the right rear portion of the sump-to-transmission gasket mating surface on the later ZF A5S 310Z transmission.
- Safely raise and support the vehicle enough that the lower portion of the transmission sump can be accessed and if necessary a fluid pump or siphon gun can be used to correct the fluid level. The vehicle must be level.
- Using the BMW DIS, MODIC, or a compatible scan tool, start the engine and monitor the transmission fluid temperature. The transmission fluid temperature must be below 86°F (30°C) before checking.
- With the engine running, press on the brake pedal, set the parking brake and move the gear selector slowly through each gear position, then place the gear selector in Park.
- If equipped, operate the air conditioning on low speed.
- Place a suitable drain pan under the transmission fill plug.
- Remove the transmission fill plug while watching the transmission fluid temperature. When the transmission fluid temperature reaches 86°F (30°C), a small stream of transmission fluid should begin to flow out of the fill hole. If the transmission fluid temperature is between 86-122°F (30-50°C) when the fluid runs out of the fluid fill hole, the fluid level is correct and the fill plug along with a new sealing washer should be installed and properly tightened.
Fill plug torque specifications:
A4S 270 R, A4S 310 transmissions:
A5S 310 Z transmissions:
- If fluid does not flow out of the fill hole, using the recommended fluid and a fluid pump or siphon gun add fluid until the fluid begins to run out of the fill hole. If the transmission fluid temperature is between 86-122°F (30-50°C) when the fluid runs out of the fluid fill hole, the fluid level is correct and the fill plug along with a new sealing washer should be installed and properly tightened. It is preferred that the fluid level be topped off at 86°F (30°C) as this allows the transmission to hold more oil than if topped off at 122°F (50°C).
- If the transmission fluid temperature exceeds 122°F (50°C) while topping off or checking the fluid level, the engine should be turned off and the transmission fluid temperature allowed to cool. After sufficient cooling, the fluid level checking procedure can again be carried out.
- Carefully lower the vehicle and test drive and check for fluid leaks and check for normal operation.
BMW recommends the use of non-hypoid GL4 SAE 80 in all models prior to 1993. Beginning with model year 1993 the 3 Series, and Z3 models use Dexron® III automatic transmission fluid (ATF). The E36 M3 models use a lifetime transmission oil (MTF-LT-1). In addition, many of the exchange transmissions supplied by BMW also contain this lubricant.
Beginning with the E36 chassis/platform, some models come from the factory with synthetic-based oils. If in doubt as to what type oil should be used, contact your local BMW dealer. BMW supplies their dealer network with Service Information bulletins to reflect updated information pertaining to procedural or technical changes in their vehicles.
Synthetics can offer easier shifting in cold weather and greater protection from wear, but can sometimes cause noisier operation and they may not be compatible with all transmissions and their synchronizers. If you wish to use a synthetic manual transmission lubricant, check with your BMW dealer for suggestions and details.
BMW states that the lifetime transmission oil MTF-LT-1 that is supplied as original equipment on vehicles with manual transmissions, does not require periodic replacement. The fluid level should be checked periodically following the maintenance recommendations, and topped off as necessary. The fluid is replaced only if repairs are performed to the transmission.
The automatic transmissions fluid used in the production of BMW vehicles will vary from model to model, year to year, and may change during a production run. If the automatic transmission is equipped with a dipstick tube, the recommended transmission fluid is DEXRON® III. On transmissions not equipped with a dipstick, the transmission fluid type should be verified by the fluid information label located on the transmission, and/or by using the transmission identification code and verifying the recommended lubricant with the help of a local BMW dealer.
When checking the transmission fluid level, the fluid temperature is critical. On models without a dipstick, the transmission fluid level can only be checked when the fluid temperature is between 86-122°F (30-50°C). On transmissions equipped with a dipstick, the difference between the MAX (Maximum) and MIN (Minimum) marks on the dipstick is only 0.6 pints (10 ounces/0.3 liter), or less than 1 / 3 of a quart!
The symptoms of an over-filled transmission include:
The symptoms of an under-filled transmission include:
Recommended transmission fluids are as follows:
Approved oils include the following:
Models requiring ATF Dexron® III
Models requiring Esso LT Lifetime Fill:
BMW recommends the use of DEXRON® III Automatic Transmission Fluid (ATF) for the 3 Series E30 models equipped with a transmission dipstick. On E30 models without a dipstick, the recommended fluid should be indicated on a label attached to the side of the transmission. If the label is missing, write down all of the transmission identification codes and consult a local BMW dealer.
The transmission fluid level should be checked at inspections as indicated by the Service Indicator. For specific information on recommended lubricants, and checking procedures, consult your local BMW dealer.E36 Models
The automatic transmissions used by BMW in their E36 vehicles varies by model, model year and production date. The numbers that are cast into the transmission cases should not be used for identification purposes.
The fluid used in the transmissions also varies over the years and from model to model. The transmissions typically have labels indicating the type of fluid to be used. The models using Dexron® III are typically labeled "ATF-Oil!" while those containing a special lifetime oil are typically labeled "Life-Time Öl" and require the use of special lubricants.
If the fluid requirements of the transmission DO NOT call for lifetime oil, use an approved Dexron® III ATF.