E60 2008 528i Transmission fluid leak

[tejastarun]

Hello guys so i had a problem with my transmission not shifting only when cold. As a preventive measure i filled up the transmission with new fluid. It took about half a gallon of fluid. I have yet to replace pan and gaskets and couple of O rings that are in the standard replacement list. But just to see where exactly is the fluid leaking i just filled up the transmission and started driving for about a day. The cold shifting problems disappeared with the oil fill. Now i am having small puddles of oil underneath the car after driving. I checked the fluid smell and it was definitely transmission fluid. I have attached a pic to show where the leaks are. Now i took it to a local mechanic shop just to lift the car so that i can see the underside more clearly. There is a lot of fluid everywhere around the pan and on the pan. there is also oil leaking from the plastic cover under the engine where the bell housing is. The mechanic there said that my transmission pump is leaking the fluid and it needs torque converter replacement to do the pump seals and just to get a replacement transmission for cheaper. Now i am not going to believe him as he clearly knew mostly nothing about this transmission. I filled the transmission up myself and made sure i did not over fill it. But i just need advice from actual gurus here to tell me where these leaks are probably present. I made sure to park in a place with no oil leaks before i parked and i moved the car to a different location just to compare and i found almost identical leak spots in both location and intensity. In the picture the small circle is right under the fill/drain plug and the arrow is towards the engine. The relatively big puddles are under the bell housing and the first 2 puddles from the top are probably engine oil or PS fluid. I do use CHF11 and i am leaking it and cannot figure out where ? My airbox is covered in oil residue after just 2 days of cleaning it and filling up the PS fluid. any help on that is greatly appreciated. So by looking at the picture can someone tell me what seals and gaskets needs replacement and what is this issue regarding the transmission pump leaking fluid where bell housing mates with the rear of the engine ? I am also noticing some strange RPM behavior. Since i changed my rear tires from 225/55/17 to 225/45/17 my speedometer shows 6mph more than what i am actually doing which is fine but ever since the transmission gave me issues when cold it shows i am doing 85/86 Mph while engine is still at 3000RPM. does this make any sense to anyone ? i thought low fluid had something to do with this. but even after filling up the fluid i am still seeing 3000 rpm while the speedo shows 91 but my GPS says i am doing 85.. please advise. Thank you.

[plus2]

The usual leak in the 6HP19 automatic is the tube like seal for the Mechatronics electrical connector at the rear of the transmission. It's a bear to replace on the X-drive models but should be easier on yours. You will need to drop the oil pan/filter assembly so you should change it too. I've done both of our e60's in my garage. I raised the rear with good ramps, then jacked the front up to install jack stands. Use the proper pad adapters. The car must be level. Of course, your garage buddy might let you use the lift which is easier.
Pelican Parts has a good tutorial and TheCTSC is also a good into and parts source.
It everything is running fine now, changing the seal and pan is probably all you need to do.
On my 530, I also replaced the square seal above the mechatronic and the 4 rubber ports into the trans body. I also did the solenoids. I was having continued shifting problems after a fluid change.

[tejastarun]

Thank you for the advice. I am going to look into the parts and procedures for that. I saw that there is a detailed procedure for all this on 5series.net too by someone who did this in the garage on jackstands. Now my main concern was something that the mechanic said about the transmission pump. And can you please confirm what rpm will you be at if the car is in 6th gear and 85mph true speed. I am a bit worried about the rpm Indicated in my car.

[plus2]

Just a wild guess until I'm on the highway but 3000 rpm seems close.

[jclausen]

if it's really oily it might benefit with a complete cleaning underneath

[tejastarun]

update ...!!! i did replace the mechatronic sleeve, the 4 tube seals and the bridge seal. took about 30 min to remove the valve body and the seals and to replace them. another 20 min to install the valve body. but took close to 3.5 hrs to replace the fucking mechatronic sleeve. Why ?? because the fucking aftermarket part was about a millimeter longer than the stock one. I finally compared the old and the new one and found out the difference and swapped out the o rings and installed the old one back in less than 5 min. another word of caution use silicon spray to lube the o rings of the sleeve. makes a ton of difference. also use some sort of leverage to push it in. it is impossible to do it with your fingers unless you are extremely skinny. The valve body is heavier than you think. since i was working close to the ground i used my floor jack to lower it slowly and pulled it our from underneath the car. As expected all the seals were hard as rock and crumbling. the bridge seal just fell apart into pieces. Before thinking its the solenoids, do the seals first if the problem persists then do the solenoids. Do not trust these cheap aftermarket parts. they are cheap for a reason. go with FCP euro or CTC or pelican parts. definitely not amazon or ebay. let me know if anyone has any questions about the procedure. I did it on jack stands with minimal space underneath the car. its a pain in the ass but if you have the right parts its easy. all i used is a t40 to remove the pan and the valve body. a torque wrench is highly recommended. do not think you can just hand tighten it. you will over torque it.

[scottalexander]

Let's say you changed your transmission fluid every year.

Do you think the bridge seal would have lasted a lot longer?

[White94RX]

By the way, BMW speedo's always read fast. Indicating 91 while doing 85 is totally normal and cannot be changed or programmed (at least not that I know of). BMW made it that way on purpose.

[tejastarun]

i dont think changing fluid every year will do anything to the health of the seals. they degrade over time regardless. mine just sort of fell apart when it was parked in cold weather for about a month. before that it was perfectly fine. i would still suggest seals to be replaced every 2 years or ~50k miles. Keeps the transmission problems away. Trust me. you do not want to wake up go to your car to see a puddle of fluid under the transmission.

- - - Updated - - -

thank you. thats a relief. I was really worried about it. somehow I did not notice this on my 04 330ci. may be it was different. !!!

[scottalexander]

Did you learn the fluid was leaking out of the mechatronic sleeve or from the pan gasket?

[tejastarun]

everywhere. the mechatronic seal and the pan. i lost about half the fluid in the transmission about 3 weeks