For 1999 X5 First generation BMW recommends to use: and genuine OEM transmission oil with a part number: 83 22 9 407 858. To select the right transmission oil see the table below.
How much transmission oil you need to put into 1999 X5 depends on conditions listed below.
Gearbox oil replacement might take 30–60 minutes, and will save you $30–$50 depends on the region you live in.
To replace oil in gearbox onin 1999 BMW X5 first locate refill and drain plugs on the gearbox body. Unscrew the refill plug first and then the drain plug. Use a spanner or a retched with the correct size head to do the job. When all oil came out screw the drain plug back with a new gasket. Refill the gearbox with new oil and screw the refill plug back.
Please be noted that all capacities listed here are approximate. Check fluid levels when adding or refilling as recommended in your 1999 BMW X5 user's manual. Keep in mind that all information here is provided “as is” without any warranty of any kind.
Before doing any DIY service please check your insurance policy and BMW warranty policy for your region. In some regions DIY service may invalidate your warranty.
DIY car service is not as difficult as it looks like and it might save you thousands of dollars per year. It might be even fun and a good thing to do with your kids on a weekend to teach them how basic machinery works. It's really hard to screw something up and damage your car permanently if you use right tools, follow BMW X5 service manual and use right parts and fluids in prescribed amounts. Even modern cars stuffed with electronics can be serviced in your garage or even in your driveway. Changing engine oil, brake fluid, ATF, replacing brake pads, and etc. It's all may be done by yourself in a mater of a couple of hours.
Doing basic service for your 1999 BMW X5 you're not only saving money, but also also improving your technical skills and learning something new.