Manual drivers - bit of shudder at very low speed creeping in 1st

JoeFromPA · 10-17-2014, 08:59 AM

Hi all,

So first, let me premise with this question: What RPM do you find yourself taking off at during normal every day driving in 1st gear?

I find myself easily taking off at 1000rpms and a very light clutch slip. I can take off much faster of course at 1500-2000rpms, but with more clutch slipping which I don't care for.

...

Ok so my real question is this: Recently I've been in bumper to bumper traffic a bit and just edging along where you literally just go to 3mph to close the gap in front of you. During this, I try my hardest to keep the RPMs minimal to minimize clutch slip...I might edge along at 600-800rpms so I'm barely outside of idle and it's only for a quick blip to get up to 3-5mph.

During this, I occasionally am getting a drivetrain shudder that is NOT engine shudder/lugging.

It feels like clutch shudder but feels like it's coming from the rear end. I have two theories and wanted to get other feedback on it:

1. It is clutch shudder as the dual plate clutch chatters lightly due to my low engine speed.

2. It's drivetrain lash felt through the solid mounted rear diff.

karussell · 10-17-2014, 09:03 AM

throttle set to comfort?

i think its the clutch in the diff you are feeling. its trying to figure out what to do with what the automated clutch is feeding. this effect is largely negated if in comfort throttle setting on DCT cars and in a manual well...only if driving like a newb.

sh55 · 10-17-2014, 09:33 AM

Quote:

Originally Posted by karussell

throttle set to comfort?

+1 put throttle in comfort when your in gridlock, makes it much smoother at low speeds.

///M/// · 10-17-2014, 10:13 AM

Quote:

Originally Posted by karussell

throttle set to comfort?

i think its the clutch in the diff you are feeling. its trying to figure out what to do with what the automated clutch is feeding. this effect is largely negated if in comfort throttle setting on DCT cars and in a manual well...only if driving like a newb.

I used to feel this in the first gear in my E90 DCT when under load in first gear standing on a slope. Only happened when just starting from a stop and up a slope (load). It was supposedly a characteristic of the DCT.

Wei718 · 10-17-2014, 10:37 AM

Has anybody noticed the car will raise the rpm slightly for you when you have it in first gear and when releasing the clutch slightly? Whenever I try to give it more fuel the car tends to be more jerky but if I use that feature it'll take off smoothly and quietly.

phil.harlow · 10-17-2014, 01:17 PM

Quote:

Originally Posted by Wei718

Has anybody noticed the car will raise the rpm slightly for you when you have it in first gear and when releasing the clutch slightly? Whenever I try to give it more fuel the car tends to be more jerky but if I use that feature it'll take off smoothly and quietly.

I noticed that the other day as well. If you're stopped with the engine at idle and gently ease the clutch out to just scoot a little, it seems to add enough fuel to keep the engine happy. Interesting stuff

solstice · 10-17-2014, 01:50 PM

Quote:

Originally Posted by phil.harlow

I noticed that the other day as well. If you're stopped with the engine at idle and gently ease the clutch out to just scoot a little, it seems to add enough fuel to keep the engine happy. Interesting stuff

Indeed, when in slow stop and go I don't give any gas, just use the clutch to slow down and get going. It's perfectly smooth.

10-17-2014, 08:59 AM	#1
JoeFromPA Colonel 1797 Rep 2,997 Posts Drives: '15 AW M3 6MT Stripper Join Date: Aug 2013 Location: SE PA iTrader: (0)	Manual drivers - bit of shudder at very low speed creeping in 1st Hi all, So first, let me premise with this question: What RPM do you find yourself taking off at during normal every day driving in 1st gear? I find myself easily taking off at 1000rpms and a very light clutch slip. I can take off much faster of course at 1500-2000rpms, but with more clutch slipping which I don't care for. ... Ok so my real question is this: Recently I've been in bumper to bumper traffic a bit and just edging along where you literally just go to 3mph to close the gap in front of you. During this, I try my hardest to keep the RPMs minimal to minimize clutch slip...I might edge along at 600-800rpms so I'm barely outside of idle and it's only for a quick blip to get up to 3-5mph. During this, I occasionally am getting a drivetrain shudder that is NOT engine shudder/lugging. It feels like clutch shudder but feels like it's coming from the rear end. I have two theories and wanted to get other feedback on it: 1. It is clutch shudder as the dual plate clutch chatters lightly due to my low engine speed. 2. It's drivetrain lash felt through the solid mounted rear diff. __________________ AW/Carbonstructure 6MT 2015 M3 picked up 8/22/2014. Stripper except for adaptive suspension. Weighed at 3,450 pounds with 1/4 fuel. 70,000 miles as of February 2020.
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10-17-2014, 09:03 AM	#2
karussell Lieutenant Colonel 356 Rep 1,749 Posts Drives: 4 wheels Join Date: Sep 2009 Location: NorCal iTrader: (1)	throttle set to comfort? i think its the clutch in the diff you are feeling. its trying to figure out what to do with what the automated clutch is feeding. this effect is largely negated if in comfort throttle setting on DCT cars and in a manual well...only if driving like a newb. __________________ "It gave you amazing satisfaction, but anyone who says he loved it is either a liar or he wasn't going fast enough." - Jackie Stewart on racing at the Nurburgring
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10-17-2014, 10:37 AM	#5
Wei718 Major 340 Rep 1,089 Posts Drives: 718 GT4 Join Date: Nov 2012 Location: Hayward iTrader: (9)	Has anybody noticed the car will raise the rpm slightly for you when you have it in first gear and when releasing the clutch slightly? Whenever I try to give it more fuel the car tends to be more jerky but if I use that feature it'll take off smoothly and quietly.
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