So far my transmission still works Week 2
Here is what worked for me on my GM 5L40E Steptronic Transmission, It has been a good 2 weeks since I did this on my transmission and now it is working great and maybe better than it use to when I purchased it a year and a half ago.
1.) I did a fluid drain and fill, Follow the fill instruction for BMW transmissions, warmed up the transmission for about 10-15 Minutes, drove the car for 15-20 Miles. Let the car cool over night and put it on jack stands.
2.) Next day, with the engine cold. Removed the fill plug and drained out about Ĺ quart of fluid and put the fill plug back in. Take a bottle of Trans Tune made by Sea Foam and a pump. Trans tune is designed to clean valves & screens, and the inner workings of the transmission as well as it takes moisture out of the fluid. Start the car and unscrew the fill plug, fill up the transmission with as much Trans Tune you can put in, screw in the plug, slowly run through the gears. Warm up the car again for 10-15 minutes and drive it around for 20 miles or so.
3.) Put the car up on jack stands, you may want to wait for it to cool a little so you donít burn your hands, drain the transmission fluid, remove the pan and pull the filter, Make sure you clean off the magnet in the pan. After pulling the filter down check to see if there are any rubber gaskets stuck in the hole. If so remove them. Install the pan and gasket. Fill the transmission and add a ľ bottle of Trans Tune while you are filling it up. Start the car and fill up the remaining amount with transmission fluid.
Hopefully it will work for you. It did for me. I had done a transmission fluid and filter change one year before and put on about 10k then this happened. Thinking back I should have done another fluid change to get all the old fluid out. Looking back at the fluid it was very dark since I donít think that it had been done for quite a while. When I changed it this go around it looked more like Tea color the first time, doing the fluid change, second time it looked better and now it looks pink.
I used Volvoline Max Life Dex/Merc, I have heard good thing about this fluid.
Its $6-7 a quart at OíReilly auto, Autozone has a Gallon (4 Quarts) for $15.99, Better deal. Each fluid change is about 6-7 Quarts
Filter and pan gasket part #FK353 are $24.99 at OíReilly Auto, only differences is the Gasket is all rubber compared to and original which is rubber and Metal. Just don't use gasket sealer on a rubber gasket or it will leak.
Good Luck and I hope it works for you!