Something happened to my transmission that might interest the group.

I have a 2010 528i with automatic transmission. Its only got 40,000 miles on it and the transmission has never been serviced. I wanted to drain the fluid and refill it. I first loosed the fill plug and then started loosening the bottom drain plug.

My brother was playing with the fill plug and took it out all the way before I could get the drain plug off. To our amazement about 1/2 a quart of fluid came out the fill plug.

How did the factory over fill the transmission? Isn't it odd and even damaging,that 1/2 quart would come out of the fill plug?

 

Perfectly normal with engine not running. Think you need to brush up on servicing the ZF HP6 transmissions.

 

Agreed. You should not have tried to get this far servicing your auto trans without already knowing this.

In many ways, yes this BMW is just a car like any other car, but in many ways it is nothing like whatever cars we worked on growing up. Don't assume you know these things.

Get the proper service procedure for this sort of work.

ZF has a great web site with all the service procedures easy to print out.