[BeastMode335i]

Hey there guys, just looking for some input from any trans gurus so I don't waste a ton of money or time heading down the wrong path here.

So my 08' 335i with 90k miles started acting up about 8 months ago, and what it would do is when shifting from 3rd to 4th it would kind of rev up a little before settling down in to the rpm range in 4th gear. I researched and figured since I was at 90k miles I'd go ahead and do a trans pan/filter and oil change (Redline D4), followed by a trans adaptation reset with INPA and see where I stood. Well after I did all that it actually made the problem worse and more pronounced, for a little while at least. After about a week of driving around, the hesitation settled back down and wasn't as bad, but it still did it. If I'm going WOT from 3rd to 4th, you barely even feel it at all and can't really tell it's there, but when going at a normal rate of speed and switching from 3rd to 4th, you definitely feel the hesitation/jerk and can see it visibly on the tach as the rpm's briefly jump up when switching gears, than after that initial jerk, 4th holds just fine. Well now I've encountered a different issue in that when I'm in 5th gear, no matter where the RPM's are, or if I shift @ WOT from 4th to 5th, it will totally "slip" and it kicks me out of M mode. I know it kicks me out of manual mode as switching from M5 back to M4, M3, M2, M1 does nothing at all until I move the shifter over to D, then back over to DS/M mode and it will then recognize that I want to manually shift again.

So I thought maybe this was a clutch pack issue, but in researching it seems that those valvebody solenoids have often been a culprit to this kind of activity, and also those seals and sleeves down there (mechatronic, etc)... When I changed the pan/filter I noticed 0 traces of clutch wear on the magnets, so I figure my clutches are fine, and I've actually read these transmissions are very stout in regards to usage.

Question 1: Is there a way to check these solenoids to see if that actually could be my problem?

Question 2: If a clutch pack went bad, wouldn't I have noticed clutch material on the magnets of the old pan?

I have been on the Alpina flash for about 3 years, also am FBO and tuned on E60 @ 18psi running RB Stage 1's, and I definitely don't beat on my car, no burnouts, no mexico trips, etc...

So I think that's about it.. Basically just trying to see if anyone had luck diagnosing a transmission and comparing whether it was the electrical side or mechanical side giving them issues.. Thanks in advance..!

[RocketSurgeon]

1-The solenoids have internal filters and complex operation, short of a dead solenoid, there's not a great way to diagnose them.
2-the friction plates are non-metallic, so you would not see anything on the magnets from them. They are also quite thin, so they would not generate much debris. I've seen ZF transmissions with 160k that had almost zero wear on the clutch plates. They last a very long time, as long as they aren't slipping or abused.

You can read the adaptation values for clues. I would suggest replacing the three little tube seals and the figure-8 seal above the mechatronic, they are a very common failure point. They shrink and bleed off critical hydraulic pressure. I would also change all of the fluid over to an m1375.4 fluid. That redline is the wrong spec, Valvoline maxlife ATF is very affordable, and M1375.4 compatible.

[BeastMode335i]

Originally Posted by RocketSurgeon

1-The solenoids have internal filters and complex operation, short of a dead solenoid, there's not a great way to diagnose them.
2-the friction plates are non-metallic, so you would not see anything on the magnets from them. They are also quite thin, so they would not generate much debris. I've seen ZF transmissions with 160k that had almost zero wear on the clutch plates. They last a very long time, as long as they aren't slipping or abused.

You can read the adaptation values for clues. I would suggest replacing the three little tube seals and the figure-8 seal above the mechatronic, they are a very common failure point. They shrink and bleed off critical hydraulic pressure. I would also change all of the fluid over to an m1375.4 fluid. That redline is the wrong spec, Valvoline maxlife ATF is very affordable, and M1375.4 compatible.

Thank you brother I really appreciate the insight.. Ordered those tube seals and that figure 8 type "double squared" seal as well.. I figured that if those seals were bad, I'd have problems in all gears not just shifting from 3rd to 4th, and when WOT in 5th.. But we'll see I suppose..!

Also thank you for the referral on the ATF, I ordered some of that as well..!

[BeastMode335i]

Originally Posted by RocketSurgeon

1-The solenoids have internal filters and complex operation, short of a dead solenoid, there's not a great way to diagnose them.
2-the friction plates are non-metallic, so you would not see anything on the magnets from them. They are also quite thin, so they would not generate much debris. I've seen ZF transmissions with 160k that had almost zero wear on the clutch plates. They last a very long time, as long as they aren't slipping or abused.

You can read the adaptation values for clues. I would suggest replacing the three little tube seals and the figure-8 seal above the mechatronic, they are a very common failure point. They shrink and bleed off critical hydraulic pressure. I would also change all of the fluid over to an m1375.4 fluid. That redline is the wrong spec, Valvoline maxlife ATF is very affordable, and M1375.4 compatible.

Oh yeah one more thing, how would I read the adaptation values for those specific solenoids? I've never done that before, so if you could just point me in the right direction that'd be great.. Is it done through INPA..??

[Komec]

*bump* I would like to get answer for this as well

[RocketSurgeon]

I'll look tomorrow in INPA and ISTA. I'm pretty sure both can read them off

[RocketSurgeon]

Sorry for the delay, I've been busy. I could find how to reset adaptations in INPA, but not where to read them. I found them in ISTA+ though. It's under vehicle management>service functions>transmission>read or clear adaptations. It shows clutch A-E with clutch fill pressures and rapid fill times for each of the 5.

[NapsterAU]

Originally Posted by RocketSurgeon

Sorry for the delay, I've been busy. I could find how to reset adaptations in INPA, but not where to read them. I found them in ISTA+ though. It's under vehicle management>service functions>transmission>read or clear adaptations. It shows clutch A-E with clutch fill pressures and rapid fill times for each of the 5.

I have 5th gear slip and have so for some time now.
I replaced solenoids and the rubber gaskets between the mech unit and gearbox and still could not resolve 5th gear slip.

I did however have a large buildup of gunk on my magnets and my trans was at 200k KM
I now have a spare gearbox sitting in my shed which i need to swap in at some point. I just find it strange that 5th has failed when it get's hardly any abuse

Also to read adaptions you can now use xHP TCU Flash Tool

[seccsc]

Originally Posted by NapsterAU

I have 5th gear slip and have so for some time now.
I replaced solenoids and the rubber gaskets between the mech unit and gearbox and still could not resolve 5th gear slip.

I did however have a large buildup of gunk on my magnets and my trans was at 200k KM
I now have a spare gearbox sitting in my shed which i need to swap in at some point. I just find it strange that 5th has failed when it get's hardly any abuse

Also to read adaptions you can now use xHP TCU Flash Tool

Looks like possibly two different areas of the valve body that may be the culprit.

https://s3.amazonaws.com/sonnax-dev/...AutoChoice.pdf[IMG][/IMG]

[TemjinX2]

before you do all that....i say give it one more try with oem atf. transmissions are very sensitive to what kind of fluid they use

[seccsc]

Originally Posted by TemjinX2

before you do all that....i say give it one more try with oem atf. transmissions are very sensitive to what kind of fluid they use

I don't necessarily agree. Fluid will cost you more than $100. Sonnax zf6-gen2-zip kit will cost $100. If you drop the fluid, change it, and that doesn't work. You still have to change the fluid again when reworking the valve body. Except instead of replacing just 4-5 quarts, now you've added additional ~7quarts and the valve body kit. At $20 a quart, that adds up.
That is just my opinion.

[NapsterAU]

Originally Posted by seccsc

Looks like possibly two different areas of the valve body that may be the culprit.

https://s3.amazonaws.com/sonnax-dev/...AutoChoice.pdf[IMG][/IMG]

Shit if i had known that i would have done the whole valvebody in one go.

[matreyia]

Here some things to sort out.

1. Make sure you have ZF or BMW fluid and not aftermarket brand otherwise you cannot procede with certainty. On stock 6hp21 transmissions use only stock fluids. I don't care what anyone thinks they "know" about the matter.

2. Valve bodies are very robust. You can try sonnax kit along with replacement of solenoids with new set. But I don't think that is the issue.

3. Clutch packs are nigh indestructible if driven stock turbo...even at aggressuve driving.

4. Your bushings are therefore the likeliest cause of your shifting woes. Unfortunately you have to take apart entire trans. To replace them. Use Propulsive Dynamics bushings if you can. Otherwise same thing will repeat after time.

While trans is apart, replace all seals and o rings qith overhault kit. And again...do not cheap out with fluid. Avoid aftermarket brands.

[Boland01]

Our 335i with 94K started shifting erratically and would go into neutral while driving. When you shut it off and restarted it would be fine for a while.

I changed the pan, fluid, and solenoids. Turns out the real culprit was the adapter seal that was torn. It sits above and connects the valve body to the transmission. I also changed the three other seals along with the mechatronics seal.

Ever since that it shifts like new. I'm thinking the torn adapter seal was causing a loss of pressure transfer. I did also have a code. I think it was implausibility between 3 and 4 gears. I did not have any debris in the fan or fluid. Hope this helps.

[BeastMode335i]

Yeah I got rid of the car, not sure what the problem ended up being.. After driving the 8AT F30 335i I was very attracted to it so I just traded the e92 in and got the f30.. My local dealer gave me $10k even with the trans issue, so I know I could have got more out of a cash sale, but for an on the spot deal I took it..