If the transmission fluid does need to be changed on your BMW, the time it takes will depend on how old the vehicle is and how complicated it is to change the fluid.

For the most part, it’ll take a BMW service center about an hour to refill your transmission’s fluid – and maybe a little longer if they’re flushing out all the old fluid and any residue or contaminants at the same time.

Most people understand how important it is to change the engine oil and filters on their BMW, but transmission fluid doesn’t always come to mind. The question of how often to get a transmission flush depends on a variety of factors.

• For a manual transmission, most manufacturers say you need to change the fluid every 30,000 – 60,000 miles.

• Most people these days have an automatic transmission, and that’s trickier to understand. Some vehicles may never have their transmission fluid changed, unless there’s a leak or another problem. Other engines have a regular maintenance interval, just like engine oil or filters.

It is important to follow BMW guidelines on transmission maintenance. If you need to have the transmission rebuilt, that can run you up to $6,000 or more.

For more about when to change your transmission fluid, read the full article

Similar to the function that oil has in your engine, transmission fluid lubricates the moving parts in the transmission. When the fluid is worn out, contaminated or missing because of a leak, you’ll start to see – or, more likely, feel – problems with the way your transmission shifts.

• Difficulty in getting into gear or staying in gear
• A lurching or thumping when shifting. If it’s operating properly, you probably won’t notice your transmission doing its job; if you really feel the shifts, you may have an issue.
• A lag between pressing the accelerator and actually accelerating. A variety of different issues could cause this, but transmission issues could be one.
• Strange noises like whining or grinding.

If you suspect an issue, the best course of action is to take your car to your local BMW service center to get it checked out.

Actually, the first question is “Do I need to change my transmission fluid at all?” For the answer, consult your BMW Owner’s Manual. Unless there’s a leak or a problem, some newer transmissions are designed to never need a fluid change.

But let’s say your car does need a transmission fluid flush as part of preventive maintenance. The top reason to change it is to keep your transmission operating at its best. Like any other fluid such as engine oil, transmission fluid becomes less effective over time. Stop-and-go driving, towing or other high-stress conditions can shorten its life even further. Unlike other fluids, however, transmission fluid doesn’t just lubricate the transmission parts, it also acts as hydraulic fluid, helping keep the transmission cooler and helping with shifts.

In a practical sense, the most important reason to perform preventive maintenance on your transmission comes down to dollars and cents: getting a transmission fluid flush might cost you a few hundred dollars, but a new transmission will cost thousands.

The first thing to determine is whether you’re able to check the fluid at all. Many modern cars don’t have a transmission fluid dipstick, so the only person who can check it is a pro.

But if your car does have a dipstick, here are a few things to keep in mind.

1. First and foremost – and this is always good advice – consult your BMW owner’s manual.
2. Park your vehicle on a flat surface.
3. Based on the owner’s manual, decide whether to check the transmission fluid with the engine on or off. Obviously, you’ll have to be a lot more careful if the engine is running.
4. Apply the parking brake for safety and make sure the vehicle is in Park.
5. Find the transmission dipstick, which is usually brightly colored and toward the back of the engine.
6. Remove the dipstick, being careful not to spill or drip any fluid. Wipe off the dipstick with a clean rag, just as you would do when checking the engine oil.
7. Reinsert the dipstick, then remove the dipstick again to check the fluid level.
8. If you need to top it off, be sure to use the recommended transmission fluid. If the fluid is particularly low, you might have a leak and should get it checked out.
9. Replace the dipstick once you verify that the transmission fluid is at the right level.