In the early years the majority of the BMW's delivered to the U.S. were equipped with manual transmissions. Most of the automatics were installed in 6 or 7 series models. Since the early 90's the horsepower ratings and transmission designs have improved to a point where owning an automatic offered very similar, if not better performance than their manual transmission counterparts. As a result the vast majority of the newer BMW's are sold with automatics. The only downside is that the automatic transmissions cannot be neglected to the degree of the manual versions. This is largely due to the fact that automatic transmissions create far more heat than a manual transmission. The heat is a result from the friction created by slipping internal clutches and bands during the numerous up shift and downshift cycles while driving. A manual transmission creates the majority of this heat within the clutch assembly, which is independent of the transmission fluid and gear assembly.

Pre 1992 Models:
This includes all 3 and 4 speed automatics prior to the e36, e34, and e32 body styles. These vehicles quite often suffered transmission failure do to lack of service and/or transmission fluid overheating due to extreme engine temperatures which in turn overheats the transmission fluid that was attempting to cool while being circulated through the vehicles transmission heat exchanger located in the engine radiator. Yes your engine radiator may be over heating the transmission fluid causing premature transmission failure due to fluid breakdown. To avoid this, vehicles that operate at the 1/2 mark on the temperature gauge during average ambient temperature (85 degrees or less) should have the cooling system repaired or serviced. If your engine runs hot, your transmission will suffer!

Items that need to be checked are:
Radiator: Check for blockage or poor heat transfer due to calcium build up. Vehicles that have over 100,000 miles should have the radiator replaced, as the plastic tanks do not allow for proper flushing.

Thermostat: If your vehicle has over 70,000 miles replace the thermostat. If you are located in a region that exceeds 90 degrees in the summer install a low temperature thermostat if available for your model.

Auxiliary Fan: This is the 2 speed electric fan in front of the radiator. This needs to operate when A/C is on and if the temperature gauge begins to rise above the 3/4ths mark.

Transmission Service
Automatic transmission fluid will break down over a period of time when subjected to extreme heat cycling. Although BMW has claimed that their later model vehicles are equipped with a lifetime fluid that does not require replacement, due to numerous premature transmission failures BMW now has modified their policy to recommend that you do perform a periodic transmission service. It is our recommendation to change transmission fluid and filter every 20,000 miles or more often if fluid condition so indicates. Most ATF is a pinkish red color and has little odor. If the fluid has a brown or very dark coloration with a burnt odor, flush and replace the fluid as soon as possible. Drain all old fluid in a clean oil pan so that you can examine it for metallic particles, which would indicate transmission internal wear or damage. Inspect the bottom of the trans oil pan for metallic glitter (remember all that glitter is not gold, it could be transmission bearing failure). Replace the filter and fill to a proper level. Since each vehicle and model may vary slightly on fluid type, for service procedure we recommend you consult your Bentley Repair Manual or call our sales staff for the proper Red Line oil for this project. Later model vehicles without oil filler tubes and transmission dipsticks are somewhat difficult for filling and checking levels. For these units we recommend collecting all drained fluids into a clean container and measuring the exact amount removed and refilling with that same quantity.

Driving School & Towing
We do not recommend these activities for any of the automatic vehicles. However if the need should arise, we recommend performing a transmission service before the event, and checking fluid for condition, discoloration, and odor after the event. Limit towing to light duty payloads.