Diff Slap?

enVmyIX · 10-27-2016, 04:10 PM

I have a 2012 335i Sport with the ZF8 sport auto tranny, RWD, and from time to time will hear a noticeable slap/clunk coming from the differential under sudden acceleration from a speed of about 20-30mph. The noise and feel is similar to going over a sharp bump on the road, and is only present when the transmission has to drop a gear or two as you mash the accelerator.

Has anyone else experienced something like this?

Coming from an Evo IX, diff slap was a common thing when shifting gears too aggressively because of the AWD drivetrain, but I figured that a RWD car will just break the rear tires loose a little and be on its merry way without any drama from the diff.

Chicken_Joe · 10-27-2016, 06:55 PM

I just get wheel hop in my car depending on how good the traction is. Usually it's a big chirp though

Lancelot · 10-28-2016, 12:57 AM

Could be worn out diff bushings, diff will bang into the rear subframe under heavy torsional load.

10-27-2016, 04:10 PM	#1
enVmyIX New Member 4 Rep 22 Posts Drives: F30 335i Join Date: Aug 2016 Location: Los Angeles iTrader: (0)	Diff Slap? I have a 2012 335i Sport with the ZF8 sport auto tranny, RWD, and from time to time will hear a noticeable slap/clunk coming from the differential under sudden acceleration from a speed of about 20-30mph. The noise and feel is similar to going over a sharp bump on the road, and is only present when the transmission has to drop a gear or two as you mash the accelerator. Has anyone else experienced something like this? Coming from an Evo IX, diff slap was a common thing when shifting gears too aggressively because of the AWD drivetrain, but I figured that a RWD car will just break the rear tires loose a little and be on its merry way without any drama from the diff.
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10-27-2016, 06:55 PM	#2
Chicken_Joe Lieutenant Colonel 606 Rep 1,782 Posts Drives: 2013 F30 335i M Sport. EB 6M Join Date: Dec 2015 Location: Frontenac, Missouri iTrader: (3)	I just get wheel hop in my car depending on how good the traction is. Usually it's a big chirp though __________________ 13' 335i M Sport. EBII/Coral Red 6MT. RPI GT exhaust, Resonator delete, PS1, GFB DV , BM3 Stage 2, ER CP, VRSF DP, VRSF 5.5in Stepped FMIC, Dinan Shockware. Carbon M Performance rear diffuser. M4 trunk lip. Conti DWS06 225/40/19 and 255/35/19
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10-28-2016, 12:57 AM	#3
Lancelot Major 568 Rep 1,291 Posts Drives: 2017 m550i Join Date: Sep 2012 Location: France iTrader: (0)	Could be worn out diff bushings, diff will bang into the rear subframe under heavy torsional load.
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