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Rear End Wiggle on Bumps
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10-15-2014, 07:18 AM | #1 |
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Rear End Wiggle on Bumps
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. |
10-15-2014, 10:24 AM | #2 |
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What did you have before, RFTs?
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10-15-2014, 04:08 PM | #4 |
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Hmm, I know I picked up on that feeling when I switched over from RFTs to non-RFTs, but never had it happen between brands of tires.
I believe the general consensus is that the soft subframe bushings the non-M E9x's come with are the cause of this squirreliness/softness in the rear end on launch and over bumps mid-turn. The non-M E9x's were setup softer to compensate for the stiff sidewalls of the RFT's that come stock on the car. |
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10-15-2014, 04:18 PM | #5 | |
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10-15-2014, 10:11 PM | #6 |
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IDK why the tires have made you notice it - but what you are noticing is the slop in the OE subframe bushings.
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10-16-2014, 07:15 AM | #7 |
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10-16-2014, 07:26 AM | #8 |
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PSS's have a lot of grip, which will exacerbate any looseness already present in the suspension.
That said, I felt the subframe wigglyness on my car when it was bone stock, low miles, and with RFTs... it's that bad |
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10-16-2014, 07:58 AM | #9 |
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Actually bumps are what first made me notice it. Esp. with the wheelbase of E8x, the back end wants to hop and skip over those bumps with the OE bushings. It was awful....
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10-16-2014, 03:13 PM | #10 |
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10-20-2014, 10:23 PM | #12 |
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i had the same feeling, upgrade your rear suspension.i went with power flex race subframe bushings and also m3 rear control arms.... rear feels PLANTED now. i also got m3 rear sway but i have an LSD. don't do sway without the limited slip.
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10-21-2014, 07:51 AM | #13 |
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I've noticed this recently as well. I have PSS' all around, and for a while, was convinced it was my rear struts. Changed them out to TCKline/Koni adj. struts, and still the rear end wiggles around over bumps. I'm starting to look at the strut mounts (Dinan for upper, Meyle for lower), and shortly after the M3 guide rods, and upper links.
Hope to report back with better results before looking at the subframe bushings but at 80k, it's a definitely possibility for slop. |
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10-21-2014, 02:46 PM | #14 |
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If you are looking to get rid of the wiggles over bumps, I would start at the subframe bushings.
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10-21-2014, 09:00 PM | #15 |
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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. |
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10-21-2014, 09:51 PM | #16 |
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trailing arm ? i would look into it pretty sure if its bad it will wiggle just like the cat lol. when i put on pss i felt that it was a soft side wall feeling and had to inflate them pretty close to max to get rid of that feeling . i must say i did love the tires other than that though.
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10-22-2014, 08:28 AM | #17 |
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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... |
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10-22-2014, 08:35 AM | #18 | |
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10-22-2014, 12:47 PM | #19 | |
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upgrade the looks of your car ... realize now you need the "Go" to match the "Show" upgrade power... realize you need better cooling upgrade cooling... realize now you need more grip upgrade tires... realize rear suspension cant cope upgrade rear suspension.... realize front end is weak upgrade front end... now brakes are not at par with rest of car upgrade brakes... realize your bank account took a big hit by buying this car |
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10-23-2014, 08:13 AM | #21 |
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I'm not sure where you live or what the weather is like now but I would recommend switching out wheels/tires with a friend (with similar size, offsets, non PS2) and see if that helps.
It could be that a lot of modified 335i guys have PS2's and they just happen to have issues. Or it could be there really is a problem with PS2's? |
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10-23-2014, 12:49 PM | #22 |
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PSS's you mean, right? Very different from PS2's.
I run PSS's on the street. I have all the M3 bits on both front and rear. No wiggle at all. |
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