x5 e53 4.4 rocks back and forth when braking

[BmwBrian]

when you finally come to a stop the car rocks front to back.

im not sure whats causing this.

theres new shocks, sway bar links, lower control arm bushings and thrust arm bushings.
lowered on H&R springs for 2 years now.

any ideas?

[TwinTurboGTR]

Has this happened before? Did it just start or did your driving style change? his topic was covered a few months ago. Other concurred it is normal. Due to braking, you should release pressure once the vehicle starts to slow down. If more pressure is applied until the vehicle stops, i.e. rapid braking all the way to a stop, the X will rock back and forth slightly.

Mine does it as well if I am key braking. If I slowly let my foot off the brake once the X beings to crawl, no back and forth movement.

[epdarks]

Warped brake rotors?

[BmwBrian]

Although now it has a fresh set of ebc green stuff pads
And brembo rotors.
With a brake fluid flush

Could be its biting harder and causing the sway

Just feels funny even when braking lightly you get
A lighter rock.

I'm going to put the factory wheels on just to see if it could be a
Tire issue...but I highly doubt it but since I'm going on a long trip
I'm swapping them we shall see.

[Big "J"]

Mine does this too. I always thought it was the gasoline swashing around in the tank that was causing the rocking.

I thought I saw somewhere that someone said they changed their rear subframe bushings and it fixed the rocking issue? Idk?

[SlickGT1]

Its a 5000lb car. Don't slam the brakes so hard. I can get it to do this too. Just be easy, unless you have to stop hard. Then don't be easy.

This will also be affected by tire sidewall height, and shock / spring age.

[TwinTurboGTR]

Bingo! Subframe bushing will take out some play but not a whole lot. Just take it easy and all is good.

[BmwBrian]

swapped my 20inch rims with toyo pro street 2 tires on them only 2 years old but seems like a tire issue. problem is gone.

it was pulling right and had 2 alignments i was checking for shits and giggles i suppose i have a ripped belt or week sidewalls.

in any case i had brand new oem michellins on the factory wheels nice and tight now.

i mentioned it as i never noticed it before im ocd when it comes to my rides i tend to notice everything and being a bmw owner for 10 years i know them well.

for now problem solved but noticed a torn cv boot !!
im just going to replace all control arms and axles on both sides.
axels are so cheap now its not worth doing just a boot.

thanks for the insight and cheers.

[Rusty Pancelode]

Mine does the rocking fore and aft thing no matter how you modulate the brakes.
It felt like the driveline to me, so I tried stopping after shifting to neutral...
Doesn't do it then, so...

[SlickGT1]

Anyone of you ever did the software update for your transmission? Your trans might be doing the lurch slightly. Only other thing I can think of.