2006 325i tranny problems...need opinions/advise

[TonyAngel]

OK, so I just ordered my tranny fluid change goodies, but a few days ago, I started having a problem. Out of the blue, I started getting a hard downshift from 2nd to 1st when coming to a stop. I'm feeling a jolt and I noticed that it happens just as the mpg gauge is popping back to the left after its trip to the far right, while stopping. I've also found that when I sit parked with my foot on the brake, I shift into DS mode, then go manual by shifting into second and it's a hard shift causing a jolt. When I go from 2nd back to 1st, it's a hard shift causing a jolt.

There are no lights on and the only codes I'm getting are those that I've been getting since I got the car which are for the eccentric shaft sensor and thermostat, which I haven't gotten to yet due to all of the crap I've had to get straight with the cars. I'm at the point of doing things in order of priority.

Of course, I know almost nothing about the inner workings of a transmission, especially BMW transmissions, but my research has led me to suspect the solenoids. So.....my question is this....

Does anyone have a definitive answer on the hard downshifts? If not, my options are: 1) When my fluid change supplies come in, do the fluid change and change the solenoids, or 2) I've sourced a tranny out of Texas for $800 shipped. It came out of a 2006 325i with 67k miles on it and I could just do a swap.

Advise?

[cochise325]

The ZF tranny is very solid. A fluid change with ZF fluid should be done first. And reset the tranny settings to the baseline. How many miles on the vehicle?

[TonyAngel]

I have 90k miles on the car. I have no way to reset adaptations, if that is what you are referring to.

[RocketSurgeon]

http://www.bimmerfest.com/forums/showthread.php?t=733273
This thread describes something similar. It's hard to say what the exact source of the hard shift was since he did everything at once. Since your car is a 2006 it most likely has the zf transmission. I'm a big fan of ZF transmissions in general, they are better built than most other brands. It's uncommon to have a problem with the "hard parts" of the transmission, so I would try to service the existing one personally. There are a couple of seals known to go bad on these that can cause slips or goofy adaptations. Theres a figure-8 shaped mechatronic seal, and three sealing tubes that sit on top of the mechatronic. It might be worth a try to reset the adaptations and see what happens. I can give you the software to do it, you just need a K+DCAN with pins 7 and 8 bridged.

[TonyAngel]

Thanks Rocket. I do, in deed, have a zf tranny. I suppose I'll have to over come my discomfort of getting into the innards of a transmission and just do it. I'm gonna drop the pan and see what at the bottom. I don't mind spending the 600 or so to fix the transmission, if that's going to do it. The cable I ordered never came in. I suspect that my postman screwed it up and a neighbor will bring it by in a day or two.

I suppose it will work out, since I've temporarily lost the use of my garage. I can do the repair in my driveway. The swap I'd wanna do indoors.

Can you believe it? My older son bought a DeSoto and has delusions of doing an LS conversion on it. Eh, I guess it could be pretty cool. I just had to tell him that my play money is tied up into BMWs at the moment.

[TonyAngel]

It's been a little while since I visited this, but this is where I am now. I did the transmission fluid/filter/pan change. When I drained the fluid, I didn't see any unusual discoloration. The fluid looked MAYBE a little thin, but that's about it. No black sludge or anything like that. The pan magnets had what I'd describe as a small amount of black sludge stuck to each of them. It had the consistency of about like vaseline. I didn't see anything that was readily identifiable a metal in the bottom of the pan or on the magnets. Still, changing the fluid did nothing to improve the stop/bump.

I also changed my eccentric shaft sensor. I wasn't getting any lights, but the codes were there. Now, the only code I'm getting is related to my moon roof. I don't know what that's about, since my roof works fine. The car runs much better at under 3k rpms now. Made a big difference. I also acquired a method of resetting transmission adaptations, so I reset them. Engine is running right and no more stop/bump, until last night. It just started doing it again.

At this point, I'm thinking it's one of two things. 1) Maybe I do need to do some sort of relearn procedure on the tranny other than just driving it after the reset. Honestly, I've been driving it a little hard since the ESS replacement because it's a lot of fun to drive now...or 2) there's something wrong with the innards of my transmission.

As I've said before, I'm no transmission guru, not by a long shot, but I have to imagine that if there was something wrong with the hard parts of my tranny, I'd be having other problems. Like the slipping or its refusing to shift or some strange grinding or something. This brings me back to seals and/or solenoids.

Can I get some advise here? I'm getting ready to put my car on stands to get the numbers off of the transmission so I can order the right solenoids.

Oh, and what's the difference between E-shift and M-shift transmissions? I think E-shift refers to the option with the shifter that is electronic (have to push a button to put it into park and stuff) and the M-shift is just the regular shifter. Depress lever to move from park to reverse to drive, etc. Is this right?

Thanks.

[RocketSurgeon]

Since you did fluid and reset and the clunk returned, I'd probably do seals and solenoids. Often times clearing the adaptations will get you a short period of good behavior, but the symptom will eventually return because the underlying cause hasn't been addressed. It's hard to say whether seals or solenoids are more likely, but for the effort of raising up the car and getting everything opened up, I'd do everything at once. Klaus with TheCTSC is great, he helped me with my ZF 5HP24 rebuild. I couldn't tell you the difference between E-shift and M-shift, unless it's electronic vs mechanical shifting. The older transmissions have a mechanical shift lever, and the newer ones are completely electronic with the f10 style shifter.
There actually is an adaptation procedure, you can find the manual here.
https://mega.nz/#!Z00z0bzK!PnhfQzmKUgJ0UFri8YCdFOsphRyJVAcX_oPUec7 ETgg

[TonyAngel]

Yeah, I guess I'm going to have to open her up again. I really like this car, especially now that it's running right, but it seems that the problems are never ending. I think I have a guibo problem.

In any case, thanks Rocket. I have seen that particular relearn procedure before, but honestly, there's no way that I can perform that procedure. I just don't have a place to do it. I guess I'll just throw more money at this thing and do the seals and solenoids and hope for the best.

[TonyAngel]

Quick question about tranny fluid. Yes, I have searched, but haven't found a definitive answer with changes in specs. I really don't want to throw another $20+ per liter of ZF tranny fluid at this thing. I've read several post regarding Valvoline Max Life Synthetic tranny fluid, which is much cheaper and readily available. Can I use this stuff in my ZF 6HP19 tranny?