Results of M5 thrust Arms

[infinity5]

well i just finished torquing, under load, my new control arms and thrust arm w/ M5 bushings...


Took it for a ride..

there isn't any difference really. the shimmy is still there, although its a little better... but now that car shimmys at 70-75MPH and vibrates slightly at speeds around there.

grrrrrrrrrrrrrrrrrrrrrrrrrrr

oh, and i found out just now that my radiator is leaking.

530ia for sale..... 120k... $6k. just needs a radiator and some... uh.. suspension trouble shooting?

I toqured *everything* back together with a brand new torque wrench. I doubled checked the tightness of the strut tower nuts, steering arm bolts, control/thrust arm bolts, sway bar links, and every single lugnut. Everything is fine unless there is some weird new issue with the thrust arms becuase of how i wedged the wrench on the nut to tighten them. like maybe getting it off loosened the nuts a little? I really really really doubt it, but its the only part of the entire project that wasn't totally by the book.

I have no idea where this new shaking is from, or why the old shimmy didn't really go away.

The tires could be the issue, but it didn't shake before like it does now, and before it shook *exclusively* at 55-60 MPH. Not to mention that when i first got the car it didn't shake period, at any speed.

Guess i'll take the wheels in to get balanced... :(

Oh, and the m5 bushings are stiffer in that i can feel more detail in the road. Its kind of annoying becuase i'm pissed off about the shaking and my seat hurts my back, but if anyone was wondering its not really a huge difference from stock.

As a matter of fact, does anyone else with lower back pain find these seats really uncomfortable?

[infinity5]

P.S. I'd like to thank Ryan for his ground-down 22mm wrench!!

[SharkmanBMW]

I had my control arm changed also and the shimmy got worse a few weeks ago... balancing did not help!
new wheels are on their way soon!!!

[infinity5]

Well maybe i if i got the car aligned?

I took it for another test drive. If anything the 55mph shimmy is worse than it was before. I'm really dissappointed.

[ryan roopnarine]

are your lower control arms and tie rods in good shape? mebbe if you got your wheels balanced on a machine that could detect bends in your wheels, the problem might be there.

[Robin-535im]

You definitely want to get a balance and alignment since you've put in the new bushings. It's worth the money!

A few other cheap things to try that might help a little:

1) swap tires front to back, or get a set from someone with known good tires. Maybe while Dan is on vacation in San Diego you could steal his :) . If the shimmy goes away, it's the tires and not the suspension, and a good balance should solve it.

2) one wheel at a time, take the wheel and brake disk off and make sure the mating surfaces from the bearing hub to the disk are perfect. Use sand paper to scour off any rust or scale and check for high spots with a sanding block (makes high spots shiny) or with a straight edge (mechanic's type). After you're sure the rotor sits on the hub 100% flush, do the same with the wheel-to-rotor mounting surfaces.

HTH

- Robin

[JAlfredPrufrock]

Check the tie rods.

[infinity5]

thanks for all the suggestions. when i had my wheels off i noticed that when i spun the rotors by hand they seemed out of round.. meaning that they woudl spin freely and then "grab" at a specific point and slow down each time they made a revolution.

This happened on both wheels, and i figured maybe it was just because the newly re-aasembled brake calliper wasn't seated properly and i just needed to pump the brakes a little.