DIY E46 Rear Differential Flush
 

Decide what you'll use. I went with Redline 75w90 High Performance Gear Oil Find more about what I used here

So, get your stuff

http://www.blinkfile.com/1375/Fluids.JPG

Then lift up the car (in my case that involved cleaning up the bay so my tech would let me use his lift :doh)

http://www.blinkfile.com/1376/Lift car up.JPG

Locate the rear differential, drain plug, and fill up plug.

http://www.blinkfile.com/1381/Rear Diff.JPG

You'll need a 14 mm Hex Socket without that tool, you cannot do this.... sorry....

http://www.blinkfile.com/1382/14 mm Hex.JPG

Go ahead and remove the fill up (top) plug, then remove and the drain plug and flush dirty fluid out.

http://www.blinkfile.com/1383/Rear Diff flushed.JPG

Put drain plug back, fill up the rear differential from the top using a pump.

http://www.blinkfile.com/1384/Filling rear diff.JPG

Once notice that it overfills, you’re done. Cap it up and call it a day :D

wat kinda pump is it exactly?

It's a suction gun. (some folks call it a suction pump) It looks like a grease gun but with a larger open end hose on it that sucks fluid up into the cylinder and then you use the pump handle on it to pump the fluid into trans, diff, whatever

You only need the pump if you have access to a nice lift like Rooz did. Otherwise, while the car is on the ground, you can do it ghetto style by using gravity.

Yea i myself had to do it ghetto style , but they do sell a pump at most autp parts that will screw right on to youe oil/Diff bottle of your favorite fluid.

Awesome post! I have a 2000 323IA and planning to change my diff fluid too. I picked up the same socket but found it difficult to completely access the fill bolt because the rear sway bar is in the way. Did you also experience this and have any tips?

TIA

so you couldn't quite fit it in between the swaybar and the fill bolt? You could always loosen the swaybar, and then tighten it back up after.

I honestly didn't...