[maxor]

So my 328 has 160k miles, I’m planning on changing the transmission fluid within the following weeks as it is due for an oil change anyways, kill 2 birds with one stone while I’m under the car.

Since I’m a second hand owner of this car, I don’t really have any service records on if the trans fluid has been changed before which is what worries me. I’ve heard some people say before that after changing trans fluid they experience issues with gear shifts etc..., or the good old “if you’ve never changed the trans fluid in 60k intervals, don’t bother changing it now” saying...

Currently the car is shifting fine and smoothly, I’d hate for the transmission to stop working after changing trans fluid.

[CTinline-six]

Doing a drain and fill can only help the transmission. I think the old wives tale about fluid at higher mileage is to not do a fluid flush. Many quick lube places have a flush machine that power flushes fluid through the transmission. This can dislodge any built up contaminants inside the transmission and send it through solenoids, the valve body, etc, not to mention quick lube shops usually don't put in the correct fluid.

Changing the fluid and filter will be beneficial to your transmission, which being a 328i should have the GM 6l45. I run Valvoline MaxLife synthetic ATF in mine with good results but any Dexron VI fluid should work well. Many on this forum have used plain old SuperTech Dexron VI and reported smoother shifting.

[kkasson]

I used Valvoline Dex-VI on mine, but yeah any Dexron 6 will work.

Be very careful that you fill the correct amount. I think almost all of the problems people report after changing it is from their fluid level being too low. If you fill it while the transmission is too warm, it will be quite a bit low on fluid.

I think the safest way to do it is to fill it as best as you can, then let it sit for at least a couple hours to cool back down and check it again. It's very hard to get it right if you're not using a scan tool to monitor the fluid temp. I was able to add at least 1/2 a quart more after letting it cool down. The filling range is 86F to 122F, so being in LA you basically want it to be full at ambient temperature.

I posted a thread a couple years back with some tips I learned doing mine, if you want to take a look: https://www.e90post.com/forums/showthread.php?t=1257476

[bkwld]

Originally Posted by kkasson

I posted a thread a couple years back with some tips I learned doing mine, if you want to take a look: https://www.e90post.com/forums/showthread.php?t=1257476

Great write up!

[AlisoBob]

Originally Posted by kkasson

I used Valvoline Dex-VI on mine, but yeah any Dexron 6 will work.

The best DEX VI replacement fluid is Mobil Delvac 1 ATF

https://www.summitracing.com/parts/m...62-1/overview/

Drain , drop the pan and swap out the filter...refill.. Run it for 10 minutes.. Drain and refill again and your done for another 100k miles.

[rothwem]

The main tip I can offer is that you should put down a big piece of cardboard under the car when doing the fluid change. I've done it three times now, and I was soooo close to not spilling any the last time, but I spilled some at the very end when my transfer pump tube popped out of the fill port.

The first time, though, it was a bloodbath. I had ATF in my hair and down the back of my t-shirt because I couldn't get the fill plug back into the transmission without burning myself on the cats. Being the bright star that I am, I figured I'd turn the car off so it could cool off and I could put the fill plug back in...bad plan. Fluid will GUSH out of the fill port when you do this.

This is a job that would be dramatically easier with a lift, so if you have access to one, you should use it. Otherwise, just try to get it as high as you can on four jack stands so that your arm can be as straight up as possible when you're putting the fill plug back in.

Oh and DON'T TURN THE CAR OFF UNTIL THE FILL PLUG IS RE-INSTALLED.

[Mantraxalos]

Originally Posted by rothwem

The main tip I can offer is that you should put down a big piece of cardboard under the car when doing the fluid change. I've done it three times now, and I was soooo close to not spilling any the last time, but I spilled some at the very end when my transfer pump tube popped out of the fill port.

The first time, though, it was a bloodbath. I had ATF in my hair and down the back of my t-shirt because I couldn't get the fill plug back into the transmission without burning myself on the cats. Being the bright star that I am, I figured I'd turn the car off so it could cool off and I could put the fill plug back in...bad plan. Fluid will GUSH out of the fill port when you do this.

This is a job that would be dramatically easier with a lift, so if you have access to one, you should use it. Otherwise, just try to get it as high as you can on four jack stands so that your arm can be as straight up as possible when you're putting the fill plug back in.

Oh and DON'T TURN THE CAR OFF UNTIL THE FILL PLUG IS RE-INSTALLED.

I made that mistake a few years back with an E46. Very messy.

[Love The Drive]

My vehicle is a manual transmission E90 328i and just passed 178k miles. More recently there was an issue with shifting. In summary, seemed like the clutch was not fully disengaging when pressing the clutch pedal in. So when letting off the pedal, the clutch would nearly immediately engage, which is unexpected given the normal engagement point is much higher up. Was not happening all the time, more so when revving high RPMs/quick shifting. So I was shifting and driving it like a grandma letting off very slowly to not let it "pop" on release for a few weeks.

Was due for an oil change and tire rotation so I took it in to my mechanic and he first checked the slave valve and master valve for leaks, which there were none showing. As a simple starting point he then checked the transmission fluid level, which was just slightly low, and suggested flushing and refilling the transmission fluid before diving into opening up the transmission. He had also asked me if the clutch was slipping at all, and it is not, so one additional reason to avoid opening up the transmission given the additional time and labor cost. (Still on the original clutch BTW! )

Been driving the car for about a week now since the transmission fluid change, and the issue seems to be minimized to nearly gone. Shifting is also much smoother as it was previously very difficult putting the shift knob into gear at times. Although time will tell, I'm not convinced the fluid change completely resolved the clutch not-fully-disengaging issue I was having, but the transmission is definitely happier now.

By the way, he also noted that old fluid was black while the new fluid is more transparent, so it was well overdue for a change.