Rear End Wiggle on Bumps

CALWATERBOY · 10-23-2014, 01:51 PM

Quote:

Originally Posted by JStang

I recently had new Michelin PSS's put on and since have noticed that the back end seems to move a little side to side when one wheel hits a bump in the road. I haven't noticed this if both wheels hit a bump.

What could be the cause? Worn subframe bushings, struts going bad, control arm bushings, bump stops etc? It's really an odd feeling.

Replace those wimp stock subframe bushings w/M3 - ~$260 parts. Use HP Autowerks' subframe bushing tool - rents for, what, $55?

Distinct improvement! Now start saltin' away that spare change for a LSD....

parksjm7 · 10-23-2014, 02:17 PM

I replaced the rear traction strut and upper control arm recently but couldn't tighten the bolts and nuts properly given the space. it's something like 79 lbft at the subframe and 125 lbft at the hub. I experienced the same loose wiggling rear end.

I wasn't going to buy tools just to do this job - I took it to midas and they torqued them to spec for $30. Problem gone.

I'm sure subframe bushings and m3 susp components will solve the problem too, but this is what did worked for me.

If you need more details, PM me.

robc1976 · 10-23-2014, 02:30 PM

Quote:

Originally Posted by whosdady

I have this wobble/wiggle and I have the 235F/265R PS2 tires as well. My suspension has been replaced 100%. Ohlins, Power Flex, M3, OS Giken, Megan, etc... I have had 6 different alignments and my car pulls/steers to the right under hard acceleration. It drives completely straight under normal acceleration. The only thing I don't have is a lockdown kit or brace.

This is not the first time I have heard of issues with the PS2's. SteveAZ had similar issues prior to changing tires...

Scott, you have PSS

whosdady · 10-23-2014, 06:45 PM

Thanks Rob. You're right, I have the new PSS which are the replacements for the PS2's.

MIL.SPEC · 10-28-2014, 07:36 PM

Quote:

Originally Posted by DrRobert

IME my 335 had two distinctly different types of rear bounce. See my post #41 in this thread for my detailed description:

http://www.e90post.com/forums/showthread.php?t=1024256

Based on the photo of the kitty (sideways rear end wiggle going over a bump while turning) I would agree you are most likely feeling the inherent weakness of the stock subframe bushings. That is an expensive repair though (if you are paying someone to do it for you), so I'd make sure you are talking about the same rear bounce as the other people who have replied. If it is more of an up and down rear bounce when going over bumps I'd have a look at your dampers.

From what I understand, the subframe inserts by Whiteline is a simple, straightforward job. If you opt for M3 bushings, well, that's a whole lot more involved.

AWD Addict · 08-15-2019, 09:42 PM

Just installed the subframe bushing inserts (whiteline). Definitely improved the left /right wiggle/slop quite a bit on my tired originals. I think I'm going to do the m3s this fall when I swap my winters on though. There's still enough wiggle that I notice it.

streetpro · 08-19-2019, 03:14 AM

Quote:

Originally Posted by JStang

to move a little side to side when one wheel hits a bump in the road. I haven't noticed this if both wheels hit a bump.

Worn subframe bushings, replace them with after-market or M3. I has helped a lot for me but I still had rear steering when on/off WOT. I have solved it by lock-down kit.
Rear M3 arms has not changed it too much, toe-arms with solid joints also just a minor improvement.

Tambohamilton · 08-22-2019, 05:13 PM

+1 for rsfb, but also alignment... Make sure you take it to a shop who knows what they're up to. A piece of string would also be a good ballpark check.

I did M3 rsfb recently, and it was a hell of a job...not fun! If you're going to do it yourself, spend the money on buying or renting the proper bushing press - it's worth it! Also I can hear my diff now, faintly.

streetpro · 08-26-2019, 03:22 AM

I don´t hear the diff at all, no even with that lock-down connection (I was kinda of afraid of that direct link between diff case and support frame)...

Tambohamilton · 08-26-2019, 05:28 AM

Yeah, I should probably change the oil in mine (130k miles old...)

hellokitty · 08-28-2019, 12:07 AM

Quote:

Originally Posted by AWD Addict

Just installed the subframe bushing inserts (whiteline). Definitely improved the left /right wiggle/slop quite a bit on my tired originals. I think I'm going to do the m3s this fall when I swap my winters on though. There's still enough wiggle that I notice it.

Go with aluminum. No nvh and keeps everything FIRM in the rear

ExtensionCable · 09-15-2022, 07:17 PM

FYI, my recently purchases 2011 E92 with 82k was having the rear end wobble problem. Just as you have all described: going over uneven bumps above 40 mph and the rear wobbling from side to side, mile after mile, week after weeks of bumps. Took it to an experienced BMW independent shop. They saw my run flat tires were quite scrubbed down on outer sides. Suggested I get an alignment first along with new tires. Well.... problem completely gone now. They found the front and the rear were way out of alignment and would therefore be likely to want to change direction at any new bump. I chose Pirelli non-run flats which I assume would make wobble worse. But no, it was the alignment that was the problem. Very pleased.

10-23-2014, 02:17 PM	#24
parksjm7 Second Lieutenant 81 Rep 228 Posts Drives: E92 07 335i Join Date: May 2012 Location: Edison, NJ iTrader: (0) Garage List 2007 BMW 335i [0.00] 2002 Honda [0.00]	I replaced the rear traction strut and upper control arm recently but couldn't tighten the bolts and nuts properly given the space. it's something like 79 lbft at the subframe and 125 lbft at the hub. I experienced the same loose wiggling rear end. I wasn't going to buy tools just to do this job - I took it to midas and they torqued them to spec for $30. Problem gone. I'm sure subframe bushings and m3 susp components will solve the problem too, but this is what did worked for me. If you need more details, PM me.
	Appreciate 0 Quote

10-23-2014, 06:45 PM	#26
whosdady Major 135 Rep 1,075 Posts Drives: 335i Coupe Join Date: Aug 2012 Location: STL iTrader: (10)	Thanks Rob. You're right, I have the new PSS which are the replacements for the PS2's.
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08-15-2019, 09:42 PM	#28
AWD Addict Chief Executive 300 Rep 2,886 Posts Drives: 2008 335xi 6spd Coupe Join Date: Dec 2007 Location: Boston iTrader: (1) Garage List 2008 335xi [0.00]	Just installed the subframe bushing inserts (whiteline). Definitely improved the left /right wiggle/slop quite a bit on my tired originals. I think I'm going to do the m3s this fall when I swap my winters on though. There's still enough wiggle that I notice it.
	Appreciate 0 Quote

08-22-2019, 05:13 PM	#30
Tambohamilton Brigadier General 3058 Rep 3,909 Posts Drives: E91 330d Join Date: Apr 2019 Location: Herefordshire iTrader: (0)	+1 for rsfb, but also alignment... Make sure you take it to a shop who knows what they're up to. A piece of string would also be a good ballpark check. I did M3 rsfb recently, and it was a hell of a job...not fun! If you're going to do it yourself, spend the money on buying or renting the proper bushing press - it's worth it! Also I can hear my diff now, faintly.
	Appreciate 0 Quote

08-26-2019, 03:22 AM	#31
streetpro Second Lieutenant 87 Rep 236 Posts Drives: e92 335iA Join Date: Nov 2018 Location: Prague iTrader: (0) Garage List 2006 Bmw e92 335iA [0.00]	I don´t hear the diff at all, no even with that lock-down connection (I was kinda of afraid of that direct link between diff case and support frame)... __________________ "If everything seems under control, you're not going fast enough.” Mario Andretti
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08-26-2019, 05:28 AM	#32
Tambohamilton Brigadier General 3058 Rep 3,909 Posts Drives: E91 330d Join Date: Apr 2019 Location: Herefordshire iTrader: (0)	Yeah, I should probably change the oil in mine (130k miles old...)
	Appreciate 0 Quote

09-15-2022, 07:17 PM	#34
ExtensionCable ExtensionCable 0 Rep 2 Posts Drives: 2011 BMW E91 Join Date: Jul 2022 Location: Washington, DC iTrader: (0)	FYI, my recently purchases 2011 E92 with 82k was having the rear end wobble problem. Just as you have all described: going over uneven bumps above 40 mph and the rear wobbling from side to side, mile after mile, week after weeks of bumps. Took it to an experienced BMW independent shop. They saw my run flat tires were quite scrubbed down on outer sides. Suggested I get an alignment first along with new tires. Well.... problem completely gone now. They found the front and the rear were way out of alignment and would therefore be likely to want to change direction at any new bump. I chose Pirelli non-run flats which I assume would make wobble worse. But no, it was the alignment that was the problem. Very pleased.
	Appreciate 0 Quote