So what does it sound like when a clutch pack is starting to wear or go bad?

[lemetier]

Originally Posted by TheHouseWon

Reviving thread to ask a question about my DCT:

When in 1st gear and reverse I take foot off of brake, but the car doesn't move until I give it a little gas. In reverse there is a bit of chatter (very little) and in 1st gear the clutch slips and doesn't grab fully until I reach around 2k rpm.

Should this be a concern or is it normal as my SA has stated?

BMW DCT (and the ZF8HP Automatic in the F85/86) do not have automatic creep from a standstill. The throttle must be depressed 1/2" or more to engage it. In manual mode the car will behave just as a non-automated manual and will roll unclutched on slopes forward or backwards after the hill assist releases. In automatic mode, it will again roll forwards or backwards, however the car will engage the clutch and creep forward if the car rolls backwards 15' without driver intervention.

Reverse and 1st are both on Clutch 1 but use different sliding clutches.

If one wants to test clutch slippage, on an incline with drivelogic in M1, engage creep mode and count the time for the clutches to fully engage. Repeat in M3 and count the time. The other obvious sign is a CCM Drivetrain error for a Hall Speed Sensor, Clutch Pressure, Shift Travel, or Transmission Temp Warning.

[lemetier]

Originally Posted by Lalit@autocouture

Keep in mind the S65 makes less than half the torque of an S63tu

But the DCT in the E9x M3 has a much greater margin safety. Fxx M5/6 are right at the limits even without CP/30J.

[apexlocator]

Well took the car into dealer and described slow speed jerkyness. They are updating the software, says it will take 6+ hrs so I'll pick it up tomorrow and see if there's any difference.

[TheHouseWon]

Originally Posted by apexlocator

Well took the car into dealer and described slow speed jerkyness. They are updating the software, says it will take 6+ hrs so I'll pick it up tomorrow and see if there's any difference.

Good luck. Did you code any features via esys? Please let us know if after the update the coding is erased and reset back to stock.

[apexlocator]

I have not started any coding because I thought a 6-hr software update might wipe everything.

[NightM]

Might as well change it to dodson stage2

[apexlocator]

Well, got the car back and I would say there's not much of a change. There might be a slight improvement in slow speed jerkyness in 1st, and overall a minor bump in smoothness of low speed, around-town driving. It would be imperceptible to anyone who doesnt drive it daily, but since its my daily, I feel there MAY be a small improvement. Could all be placebo effect too, so.....

In hindsight, I probably would not bother because I was without the beast for a day, puttin around in my EV

[lemetier]

Originally Posted by apexlocator

Well, got the car back and I would say there's not much of a change. There might be a slight improvement in slow speed jerkyness in 1st, and overall a minor bump in smoothness of low speed, around-town driving. It would be imperceptible to anyone who doesnt drive it daily, but since its my daily, I feel there MAY be a small improvement. Could all be placebo effect too, so.....

In hindsight, I probably would not bother because I was without the beast for a day, puttin around in my EV

Keep in mind it's still a manual transmission...just one with automated clutch operation. It's ability to change gears "faster" than the driver could doesn't apply for when lugging around in low speed situations. You stated earlier that S+ Throttle and S3 Drivelogic is the normal configuration, low speed, stop-go traffic can feel jerky in 1st since the clutch is trying to fully couple as quickly as possible to maximize acceleration but the conditions are the opposite. S+ throttle mapping at low speed is artificially boosted as well which can further increase the clunky feeling. When the situation is constant on/off throttle at low speed, the car has to do something to keep from stalling. Another thought is if you are the type that downshifts manually all the time and selects 1st before the car stops rather than allowing the car to do this on its own.

If the dealer doesn't suspect a mechanical problem, take a moment and pretend there is a clutch pedal to operate when you feel the jerkyness and slipping.

Its extremely rare for me to use D mode and I operate the selector the same as I would a standard manual. If there is a lot of low speed stop-go, I start off in second from a stand still.

[apexlocator]

Always like reading your posts miami, as they're always informative. I, like most on this forum, am no stranger to how a manual behaves. I just stopped by the dealer to inquire about recent software and the jerky feeling of the DCT. I think I would have been ok if the SA told me it was normal, and been on my way. But, he said there is newer software and to leave the car with them....so, what the hay.

I too rarely use D, and I do downshift but only to 3rd and let the car do the rest to a stop.

[lemetier]

Originally Posted by apexlocator

Always like reading your posts miami, as they're always informative. I, like most on this forum, am no stranger to how a manual behaves. I just stopped by the dealer to inquire about recent software and the jerky feeling of the DCT. I think I would have been ok if the SA told me it was normal, and been on my way. But, he said there is newer software and to leave the car with them....so, what the hay.

I too rarely use D, and I do downshift but only to 3rd and let the car do the rest to a stop.

Ah ok I understand now and appreciate the compliment. I had the impression from an earlier reply that you were concerned about chattering and slippage as well.

[TheHouseWon]

Originally Posted by apexlocator

Well, got the car back and I would say there's not much of a change. There might be a slight improvement in slow speed jerkyness in 1st, and overall a minor bump in smoothness of low speed, around-town driving. It would be imperceptible to anyone who doesnt drive it daily, but since its my daily, I feel there MAY be a small improvement. Could all be placebo effect too, so.....

In hindsight, I probably would not bother because I was without the beast for a day, puttin around in my EV

Did you have to pay or was it under warranty? Do you have the name or part number of the updated software? I would like to try it out. You can pm me if it's too personal or you want to recommend the service advisor that helped you.

Thank you

[apexlocator]

I PM you house, hope you got it because this site was really buggy for me yesterday...so not sure if you got 2 copies or none....lol.

[TheHouseWon]

I got it. Thanks so much!