Rattle- Left Front wheel- Solved
 

Hey folks!

Among other issues with my ABS/DSC module taking a dump (new one on order); I've been having a harsh shudder (steering wheel wobble) from the left front wheel only when braking at 40 mph + speeds. I searched and most say its the thrust arm that's the issue but, I don't think it is for me?

I've replaced the suspension components and re-torqued to BMW specs and still have the shudder.

Now after checking everything again it has an annoying rattle like if someone put a bottle cap inside your old hub caps! When I'm at a stop then start rolling the rattle isn't as apparent until I roll over the first bump/ pot hole. Then it becomes a constant rattle during driving at all speeds and when rolling over a significant bump or pot hole the rattle intensifies (if you will) with the harshness of the bump.

It's not the brakes or the spring rattling as it's nice and tight and still rattles when braking.

I'm beginning to think it's either the wheel bearing or the CV axle lost a bearing or two and is causing the wheel shudder, almost a bounce feel with the now present rattle.

Has anyone else experienced this or have a good idea what is actually causing this?

Thanks!

JJ

You need to use your air suspension, raise the car, and get under there with a crow bar. Sounds like two things, either your end link is gone, or your thrust arm is gone. Also. check the bolts holding the skid plate. If they were re-used before, they may have sheered off, and they also hold our sway bars mounts in place.

Big J,

So did you replace your front control arm bushing? If so, did you happen to check the front ball joints while you were in there?

I recently picked up a set of the powerflex front control arm bushings and replacement ball joints. It there's any play when I change out the bushings, the ball joints are going to be changed out too!

Thanks Slick!

I'll check those parts tonight and update afterwards. Ugh!...very frustrating.

Hi BB48!

I did change both arms (thrust and wishbone) along with the solo ball joint. I have the Meyle HD thrust arm bushing and does appear to be okay at rest but, as Slick suggested will take a pry bar and check it for excessive play.

How many miles on the ball joints? As you probably know when one part of the suspension is worn out it is time to replace all the other bushings and ball joints.

Have you considered the left front rotor could be warped?

Hey bud! Ball joints and all were replaced about a month ago..... a warped rotor has crossed my mind but, I replaced those about 6 months ago. I guess I'll take the rotors off and have them turned at Oreilly's or the like and see if they come back saying they're warped?

Wonder if a bad wheel bearing or bad CV axle could cause the hub to wiggle enough to make it feel like a warped rotor or bad thrust bushing?

O'reilly's may be able to tell you if it is warped but it is not recommended to turn BMW rotors. I have seen new rotors that were warped out of the box.

If it happens when the brakes are cold or have not been used for some time when driving that is a clue that it is brake related. If you can get it to happen then let off the brakes and then apply them again and it goes away and then won't happen the next time you brake from the shuddering speed that is more than a clue. Have you place the pads or rotors recently?

Have you checked the sway bar link on that side? Are bolts tight? Did you replace the links with the rest of the suspension?

If it has been doing this for some time and still only happens over 40mph I would be somewhat skeptical that it would be a wheel bearing or CV, especially with the rattle rather than a grinding or clunking noise. I would be checking other potential problems first.

The rotors have plenty of meat on them and should spec out ok if they're not warped too bad. It would be just my luck that I got warped rotors out of the box...Lol!

You are on track with the shuddering happening when cold and after I let off the initial attempt (above 40), then I don't feel it as bad when pressing the brakes and slowing to a stop or crawl. Braking under speeds of about 30 mph, the shudder isn't as noticable.

Pads and rotors were replaced last November with brembo's and semi-metalic's.

Sway bar links are over a year old but, I do have a new set of Meyle's (was for my daughters 03 X5 3.0) and will put those on tonight when checking the thrust bushes and skid plate bolts.

I hope to be toasting a "Moose Knuckle" ... I mean a "Moose Drool" beer in y'alls honor! :beerchug:This has been plaguing me for sometime!

Rattle Solved!!!

The rattle is from the round metal dust and debris cover that sits around the wheel hub on the knuckle. It jarred itself loose and was causing the wheel rattle.

Next just need to figure out the brake shudder/ steering wobble when braking from high speeds. Checked the thrust bushing and sway link and both are good. I'll get the rotor removed and have it check & turned to confirm a warped rotor and report back.

Oh! BTW- my new Bosch 8.0 ABS/ DXC module arrived and will be installing and coding that tonight! Woot woot!