[STR8-6IX]

hey guys, so i've noticed a problem that has been occurring recently with my 8 speed. whilst at a cruise (roughly 1500rpm) when i kick down a gear or two (revving at roughly 2000rpm, sometimes happens at 2500) the transmission seems to "stutter" theres no other way i can explain it but whatever its doing, it is very noticeable. I have changed transmission fluid recently. am currently at 73,000 miles.

the thing that confuses me is that it doesnt always happen, and it never does it if i downshift to a more aggressive RPM (3000RPM + usually doesnt happen at 2500) other then this, the transmission shifts smooth, quick and sturdy. no other problems to report but some ideas or help would be appreciated.

thanks guys

[madmonkey]

Did you also change the filter?

[STR8-6IX]

Originally Posted by madmonkey

Did you also change the filter?

yes of course.

[madmonkey]

I am not a transmission expert, but in doing some quick research for you, I have come across a few people who mention that a transmission reset fixed their jerky shift issues.

Now while that might not be 100% the same as your case, I think that maybe your transmission doesn't know you put in new fluid and filter. Maybe a reset will work. Posts I have seen say that a battery disconnect for 30min resets the trans ecu. I'm guessing that can't hurt anything.

[STR8-6IX]

Originally Posted by madmonkey

I am not a transmission expert, but in doing some quick research for you, I have come across a few people who mention that a transmission reset fixed their jerky shift issues.

Now while that might not be 100% the same as your case, I think that maybe your transmission doesn't know you put in new fluid and filter. Maybe a reset will work. Posts I have seen say that a battery disconnect for 30min resets the trans ecu. I'm guessing that can't hurt anything.

i changed the fluid 6000 miles ago and have already done a reset. it only happens when i downshift and force the engine to rev from a low rpm.

[madmonkey]

So like I said, I'm no transmission expert. You could be experiencing side effects of minor wear on the transmission. Check out the youtube video for more detail around the 6min mark...

[VikH]

I have similar issue where my transmission at low speeds shifts roughly or delayed. I tried to have the dealer identify and fix this issue, but they/I could not duplicate the problem. Keep us posted if you find a solution.

[STR8-6IX]

Originally Posted by VikH

I have similar issue where my transmission at low speeds shifts roughly or delayed. I tried to have the dealer identify and fix this issue, but they/I could not duplicate the problem. Keep us posted if you find a solution.

try doing a transmission adaptation reset.

[otay]

Originally Posted by VikH

I have similar issue where my transmission at low speeds shifts roughly or delayed. I tried to have the dealer identify and fix this issue, but they/I could not duplicate the problem. Keep us posted if you find a solution.

Ruh-roh. Sounds like the problems I had. After many service visits, they replaced the entire transmission. At first, they could not duplicate either. Hope it's not the same thing. The entire saga is in another thread, but my issue was delayed upshifts in lower gears.

6IX-F10-N52...problem sounds different. Happens on downshifts?

[VikH]

Originally Posted by STR8-6IX

try doing a transmission adaptation reset.

Originally Posted by otay

Ruh-roh. Sounds like the problems I had. After many service visits, they replaced the entire transmission. At first, they could not duplicate either. Hope it's not the same thing. The entire saga is in another thread, but my issue was delayed upshifts in lower gears.

6IX-F10-N52...problem sounds different. Happens on downshifts?

Thanks for the reply guys. Any risk of making it worse if I do the transmission adaptation reset? Also, is this the right procedure?

Well, tried the procedure again today, and...it worked!
- Foot off brake
- Press start to turn on car (but not start)
- Press accelerator for about 30-40 seconds
- Press start to turn off car
- Release accelerator
- Waited about 3 minutes, then started normally and drove off

[STR8-6IX]

Originally Posted by otay

Ruh-roh. Sounds like the problems I had. After many service visits, they replaced the entire transmission. At first, they could not duplicate either. Hope it's not the same thing. The entire saga is in another thread, but my issue was delayed upshifts in lower gears.

6IX-F10-N52...problem sounds different. Happens on downshifts?

I believe it has something to do with the engine. I have been getting a drivetrain malfunction lately. (happens only at high rpm, or when aggressively on the throttle when the drivetrain is still cold) a simple restart makes the problem along with the CEL go away. I believe it is a misfire that has to do with the coil packs or spark plugs.

anyways, I think this is the culprit for my stuttering problem. because it only happens when I am applying a bit too much throttle for the RPM I am at. if i back off the throttle a little and just let the engine take its time, the stuttering does not happen. I will go and finally get the car scanned and figure it out. will post with an update if the issue is resolved.

[otay]

Originally Posted by VikH

Thanks for the reply guys. Any risk of making it worse if I do the transmission adaptation reset? Also, is this the right procedure?

Well, tried the procedure again today, and...it worked!
- Foot off brake
- Press start to turn on car (but not start)
- Press accelerator for about 30-40 seconds
- Press start to turn off car
- Release accelerator
- Waited about 3 minutes, then started normally and drove off

This is supposedly the throttle adaptation reset. I haven't done it in a while, but could tell a difference after doing it. For the transmission reset, you need special software...or your dealer can do it.

I'd try the throttle reset anyway. No risk of making anything worse.

[STR8-6IX]

Originally Posted by VikH

I have similar issue where my transmission at low speeds shifts roughly or delayed. I tried to have the dealer identify and fix this issue, but they/I could not duplicate the problem. Keep us posted if you find a solution.

this is a known issue with the ZF 8 speed. the jerky shift and hesitation happens at 1500RPM right? anyways, there is a "sweet spot" in the throttle position that will prevent the shift from jerking the whole car. you just have to experiment at low speeds in a parking lot or something and find it.

also, please refer to the post above this one. I believe the problem I am talking about is engine related and not transmission.

Originally Posted by VikH

Thanks for the reply guys. Any risk of making it worse if I do the transmission adaptation reset? Also, is this the right procedure?

Well, tried the procedure again today, and...it worked!
- Foot off brake
- Press start to turn on car (but not start)
- Press accelerator for about 30-40 seconds
- Press start to turn off car
- Release accelerator
- Waited about 3 minutes, then started normally and drove off

there is no harm in doing an adaptation reset and yes, that is the right way to do it. it will probably help, but like I said you do need to find that sweet spot to help with low RPM jerkiness. It would help to reset your transmission when you buy a used car or something like that.

[VikH]

Thanks for the help. I will try the adaptation reset today.

Yeah, I have seen other threads complaining about this issue. I have had the car for almost 4 years and the transmission has not been like this previously. There are times where the shifts are jarring which is not normal and leads me to think either it's software or hardware problem. Just bought extended warranty so hopefully will be covered if trans needs to be repaired.

[rinaprasant]

dear , its sure gearbox problem 100% , i change 2 & code with exproller job done , but i want to know where is the problem in gearbox
1 valvbody , 2 megatronic 3 cluth problem

thanks

[eluded]

73k + miles ? That's uncharted territory?

[BMW1984N55]

73k + miles ? That's uncharted territory?
__________________

If Ali says a mosquito can pull a plow, don't ask how. Hitch him up.
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I am sitting at 42k miles and i have harsh shifting on my 8 speed. worse when cold, but pretty much always there. Slowing down i get a bump when almost to a stop, and taking off is delayed and not even close to smoothe and linear. 2012 BMW 535i. Im thinking about getting a seperator plate and solenoids and rebuilding the mechatronics myself.