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How to Drain and Fill Transmission Fluid 97-06 BMW 325Xi

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How to Drain and Fill Transmission Fluid 97-06 BMW 325Xi

Created on: 2021-01-16

This video shows you how to drain and refill the transmission fluid on your 01-05 BMW 325Xi. 1A Auto shows you how to do it yourself!

  1. step 1 :Draining the Transmission Fluid
    • Remove the Phillips screws securing the transmission trim panel
    • Remove the transmission trim panel
    • Remove the T40 drain plug
    • Allow the fluid to drain into a pan
    • Reinstall the T40 Drain Plug
  2. step 2 :Refilling the Transmission Fluid
    • Remove the 17 mm transmission fill plug
    • Fill the transmission with fluid specified by the manufacturer using a fluid transfer pump
    • When the fluid drains steadily from the fill hole, reinstall the fill plug
    • Run the vehicle and cycle through the gears
    • With the vehicle still running, remove the 17 mm fill plug to check for a steady stream of fluid
    • If there is no stream of fluid, more needs to be added
    • Be careful around the exhaust while the engine is running
    • Reinstall the transmission trim panel with the Phillips screws

Tools needed for replacement

  • General Tools

    Drain Pan

  • Star Drivers & Sockets

    T40 Socket

  • Wrenches - Metric

    17mm Wrench

Installation Video
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What's up, guys? I'm Andy from 1A Auto. In this video, I'm going to show you how to drain and fill the automatic transmission fluid in this 2001 BMW 325xi. If you need parts for your vehicle, click the link in the description and head over to

To gain access to any of the transmission area, you're going to need to remove this panel. There's some Phillips head screws, these are retainers that hold it in. We already took these out because they're a little bit rusty. Most of these are broken, so there, there. There's two right there, and one goes right there, we just slide that off.

So, I want to drain this transmission pan, there is a drain plug. I'm going to use a T40. Now, this drain plug's pretty rusty, so I'm not sure if it's a T40 or a T45, T40 fits, but it does seem a little bit loose. Let me just try. All right, I'm going to try the T45, so I'm going to use a T45. I'm just going to tap it in. There we go.

Now, I'll just use a socket, loosen it up. Open this up. Make sure you have a drain bucket underneath to catch the fluid. And that fluid looks pretty nasty. Should have a red color to it, and it does not, definitely not red. Right, now that's dripped out, most of the fluid. I'm going to take the drain plug, put the drain plug back in, just make sure the seal looks okay on that, there's a little O-ring on there.

Take my ratchet and snug it up. That's good. All right, I'm going to take a 17-millimeter wrench, and I'm just going to take the fill plug out, loosen that up. It would be a good idea to pull this fill plug out before you actually started draining the fluid, just in case this does not come out, because in that case you would not be able to get fluid into the transmission. So make sure you try to take this off before you drain the fluid, or take the pan off, we forgot to do that before.

Now we're going to want to transfer the fluid. You can use a pump and make sure you use the appropriate fluid, you can check the owner's manual to make sure you got the right fluid. A lot of times it tells you what kind of fluid right here, so check that. And then, we're using this gun-style pump. This is more like a grease-gun-style fluid transfer pump, so we put the fluid in here and then transfer it in there. Takes a lot of effort, so a regular pump would work better.

All right, there we go. Oops. All right, I'm just putting my finger over the hole for a second, all right, and I got a nice stream coming out, which is good. So, what I'm going to do now is I'll take the fill plug, put that back in, and I don't have tighten this all the way down, but I am going to start the vehicle and run it through the gears and then with the vehicle running, still in Park, we're going to come back down and check it.

To check the transmission fluid level, I need to start the vehicle, let it run for a minute, shift from Park to Reverse to Drive, then back to Reverse, then back to Park, do that a couple times, and then I'm going to raise the vehicle up, and I have to check it at the fill plug with the vehicle running. You want to do this before the transmission warms up too much, if it warms up over 130 degrees, then you're going to have to wait till it cools down.

A 17-millimeter wrench, I'm going to check. The pill plug is right here. Pull this out. Now, we want to see a slight stream of transmission fluid. There's no stream, so what we're going to do is we're going to add a little bit of transmission fluid.

Keep in mind the engine is still running. It is getting pretty hot right here near the exhaust, so be careful. Ah, there's the little stream. I'm just going to hold my finger over the plug for a second in the fill hole, and that looks pretty good, so that's a nice stream draining out, so that's full. That's what you want. Take the fill plug, if you have a new seal, put it on, and this one looks pretty good.

Take our 17-millimeter wrench and snug it up. That looks good. Take a little break parts cleaner, and wash off the excess. Just be careful around the exhaust.

Thanks for watching. If you want the parts to do it yourself, check out, the place for DIY auto repair.

Tools needed for replacement:

    General Tools

  • Drain Pan

  • Star Drivers & Sockets

  • T40 Socket

  • Wrenches - Metric

  • 17mm Wrench

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