fsim6080

I have just replaced the transmission on my 2008 BMW 528xi (LCI), and I am running into some serious issues. I have spent hours researching and trying to fix these issues and have not been able to find a similar issue to mine. I have learned a lot from these forums but it is my first time posting on any car forum my entire life: I am at my last resort.

For background information, my original 6HP19 transmission started throwing the dreaded E clutch error. Long story I replaced the solenoids and serviced the transmission too late. I decided to purchase a used transmission off of eBay. I paid a premium for it as it had only 65k miles and came off of a 2008 BMW 528xi, which was an exact match. I replaced the transmission following the BMW TIS repair manual. Additionally, I replaced the 5 mechatronics to transmission seals, the mechatronic TCM connection seal, put new solenoids, new oil pan, and ZF Lifeguard fluid into the transmission. All of these parts were genuine ZF OEM parts.

My problems started while trying to fill the transmission with fluid. I followed the TIS repair manual pumping fluid into the tranny until it was dripping out. I closed it up and started the car, and after this, I checked the fluid again and it was at the same level (dripping out). I then let the car warm up and tried to shift into gear per the standard fill procedure. The car would not go into gear. The shifter shifts into D or P or M1 and M2, and lights up showing that it’s in that gear (also says that on the dash) but approximately 2 seconds after shifting it into gear the shifter clicks back to park. The car is not actually going into gear. I ran codes on the car with my Foxwell scanner and the only code that I am getting in regards to the transmission or drivetrain is error code A0B1, CAS input selector-lever position implausible. Everything that I am reading online was pointing to the mechatronics sealing sleeve or a possible pressure leak between the mechatronics and transmission. Additionally, after warming up the car and trying to shift into gear, fluid is still dripping out of the hole: the fluid is at the exact same level. I put in roughly 3 to 4 quarts but the transmission is completely empty as I drained it and should take 7 quarts. Basically, the tranny or TCM isn't working to suck up the initial fluid.

To fix this I thought that maybe my mechatronics or sealing sleeve was not seated properly. I removed the mechatronics again to check the sealing sleeve and re-torque it down and nothing was out of the ordinary. Because of this, I decided that it could be the TCM that came on the used tranny so I swapped it with my old one as I know that it worked. I reassembled it and I am still having the same issue. I thought about what it could be next and I came up with a course of action: maybe I got sent the wrong mechatronics rectangular seal (the one that goes into the 6HP26 looks the same but is 14.4mm tall instead of the 15.4mm that my 6HP19 takes.) My plan was to drop the mechatronics again and measure the seal. If it was the wrong one then there was my issue. If it wasn’t then I decided that I should put my old mechatronics back into the car swapping the new solenoids onto it (because it worked.). I dropped it again and measured that seal, it was the right one. But I also noticed some metal shavings on the rectangular mechatronics seal. These were on the top of the larger square section of the seal. The shavings were also inside of the mechatronics right below the seal. I have included pictures of them and I believe that they came from the transmission.

I am wondering if anybody knows what is going on here, or has any experience running into an issue like this? I had removed the mechatronics on my old transmission twice to replace the seals and then the solenoids and it worked after that so this was not my first time performing the job on the mechatronics, I don’t think that these issues are resulting from an error in my work.

Sorry for the long post, but I thought that it was necessary to describe all of the details, as I have seen similar issues to this on forums but they all happened to be a defective seal, and mine is in perfect condition.


I noticed metal shavings on top of the mechatronics seal. Looks like they came from above inside of the transmission its self.

Metal shavings below seal inside of mechatronics.

Only error code that I am getting in regards to the drive train.

seanjordan20

Is the selector lever on side of the mechatronics(the one you can slide back and forth) in the right position before closing it up. It's not seeing the car in the park position. That's all I can think about.

If the plug didn't seat all the way you would have a "press the brake to start" message.

Do you have a BMW scanner to see more than what error you are getting now?

scottalexander

You said you put in roughly 3 to 4 quarts but the transmission is completely empty as I drained it and should take 7 quarts. Basically, the tranny or TCM isn't working to suck up the initial fluid.

Historically, in past posts on the forum when the 6hp19 won't take a second fill (when the engine is running), one of the issues is a bad transmission oil pump. That is, the pump is not circulating the oil in the pan.

If you were using ISTA, would ISTA identify a bad oil pump?

fsim6080

Yes I have made sure and adjusted the selector lever into the right position position before closing it up.

I have a BMW scanner, that code that I posted is the only code that it is picking up. It's the Foxwell scanner with BMW specific software on it.

fsim6080

I don't think that ISTA or any software would identify a bad oil pump. I believe that I would get an error similar to the one that I got, which basically can be triggered by a lack of pressure in the mechatronic. I am also really thinking that it might be the transmission oil pump, especially after seeing those metal shavings. They were not there when I originally mated the valve body to the transmisison.

scottalexander

Regarding a potential bad oil pump in the ZF box, I was watching a Youtube video recently of Gary Ferraro transmissions. He tears down ZF transmissions on a daily basis.

When he pulled apart one of his customer's ZF transmissions the oil pump had a few teeth disconnected and the entire main gear on the oil pump was split in half. In this case, no oil was circulating.

My question was how could the pump split in half?

I can see the clutch packs wearing and the A clutch and E clutch bushings wearing, but how does the oil pump gear get severed in half?

Redballs1

This could be a coding conflict in the cas module, this will occur if the doner vehicle had paddle shifters and your’s do’s not or vice versa. Do you have access to NCS-expert to read the module? If so i’ll tell you what the settings should be.