Slight thump sound and jerky feeling from the rear when switching gears ?

tscdennab · 07-12-2011, 03:11 PM

Hi,

I replaced my clutch with an OEM one, and after breaking it in for about 250-300 miles (of which 100 in city traffic) I went to a drag strip event (12.56@113

). The clutch works perfectly, but on the way home from the strip I started to notice a "thump" sound coming from the differential area when switching gears and the gear change feels a bit jerky. I "think" it was also present before the drag strip event, but to a lesser extent. It feels like a "play" or "slack" somewhere on the drivetrain. One problem is that the new clutch seems to grab more abruptly compared to my old one (visually they are identical though), could this be the problem of me not being used to it and lifting my foot from the pedal too abruptly ? Maybe the driveshaft rubber mounting to the gearbox is worn ? Or the rubber piece that unites the two driveshaft parts is worn out ? I don't want to think about differential gear play yet...but who knows. I also read stories about damaged clutch plate springs...

Anybody had this problem before ?

Thanks !

Potty_Pants · 07-13-2011, 05:18 AM

subscribed... i wish you luck.

from an unedumacated point of view id say drivetrain linkage like you suggested.

ppp

Dr_Dirt · 07-13-2011, 07:49 AM

Just a guess but I wonder if your dragstrip run may have worn out the motor mount bushings causing some backlash effect you feel in the rear differential.

07-12-2011, 03:11 PM	#1
tscdennab Banned 151 Rep 1,809 Posts Drives: BMW 335i Join Date: Oct 2010 Location: Europe iTrader: (0) Garage List 2008 BMW [6.24]	Slight thump sound and jerky feeling from the rear when switching gears ? Hi, I replaced my clutch with an OEM one, and after breaking it in for about 250-300 miles (of which 100 in city traffic) I went to a drag strip event (12.56@113 ). The clutch works perfectly, but on the way home from the strip I started to notice a "thump" sound coming from the differential area when switching gears and the gear change feels a bit jerky. I "think" it was also present before the drag strip event, but to a lesser extent. It feels like a "play" or "slack" somewhere on the drivetrain. One problem is that the new clutch seems to grab more abruptly compared to my old one (visually they are identical though), could this be the problem of me not being used to it and lifting my foot from the pedal too abruptly ? Maybe the driveshaft rubber mounting to the gearbox is worn ? Or the rubber piece that unites the two driveshaft parts is worn out ? I don't want to think about differential gear play yet...but who knows. I also read stories about damaged clutch plate springs... Anybody had this problem before ? Thanks !
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07-13-2011, 05:18 AM	#2
Potty_Pants Colonel 66 Rep 2,189 Posts Drives: 2012 Genesis Sedan Rspec Join Date: Apr 2007 Location: Southern NJ iTrader: (0)	subscribed... i wish you luck. from an unedumacated point of view id say drivetrain linkage like you suggested. ppp __________________ Olds Starfire > Chevy Malibu > Isuzu I-mark RS & Honda Magna 500 > Grand Am GT & YSR50 > Nissan Maxima & Ninja 750 > X-Wife > Hyundai Excel > Honda Prelude > Honda Accord > Honda Prelude & Ninja 250> Infiniti G35 > E90 335i > Hyundai Genesis Rspec, Hyunadai Sonata > Kia Sorento > Honda CRV-EX
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07-13-2011, 07:49 AM	#3
Dr_Dirt Major 62 Rep 1,476 Posts Drives: E90 335i 6AT Join Date: Apr 2007 Location: DFW iTrader: (1)	Just a guess but I wonder if your dragstrip run may have worn out the motor mount bushings causing some backlash effect you feel in the rear differential.
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