Light clunk w/brake

[ecrabb]

Sitting at a stop light, maybe on a light incline or something... Release brake a little, and poke it back on... I can feel a little but of a "clunk" that seems to translate well through the steering right back up into the steering wheel where I can feel it.

CABs?

Almost 42,000 miles on the car now.

Thanks!!!
SC

[BCS_ZHP]

So with the boss and several other long termers invited to my house in Oct 2012, I did a brake job the week before as PM to ensure I was ready for some spirited driving. A day or two later I heard a clunk when pressing the pedal at slow speeds. I assumed it was suspension related so for this mini-meet I ordered and had the dirty dozen assist me in replacing my whole suspension on a 68K mile car with a complete Dealership sourced suspension refresh. Afterwards, still had the clunk at slow speeds. Our boss himself was driving, coming back into my driveway, myself and others alongside the car to try to find the noise. It ended up being the brake caliper carriers themselves, I obviously had not tightened them enough and they loosened up the more I drove the car and used the brakes. Now, I tighten the brake carrier backets by hand and then smack the rachet with a hammer a couple of times to ensure they are more fully tight.

[danewilson77]

So with the boss and several other long termers invited to my house in Oct 2012, I did a brake job the week before as PM to ensure I was ready for some spirited driving. A day or two later I heard a clunk when pressing the pedal at slow speeds. I assumed it was suspension related so for this mini-meet I ordered and had the dirty dozen assist me in replacing my whole suspension on a 68K mile car with a complete Dealership sourced suspension refresh. Afterwards, still had the clunk at slow speeds. Our boss himself was driving, coming back into my driveway, myself and others alongside the car to try to find the noise. It ended up being the brake caliper carriers themselves, I obviously had not tightened them enough and they loosened up the more I drove the car and used the brakes. Now, I tighten the brake carrier backets by hand and then smack the rachet with a hammer a couple of times to ensure they are more fully tight.
[emoji12]

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[TristanHunter]

Sitting at a stop light, maybe on a light incline or something... Release brake a little, and poke it back on... I can feel a little but of a "clunk" that seems to translate well through the steering right back up into the steering wheel where I can feel it.

CABs?

Almost 42,000 miles on the car now.

Thanks!!!
SC

I had a similar issue when I first bought my car. Grabbing the brakes fast or releasing them after I stopped caused a minor clunk and a "twitch" in the steering wheel. FCABs fixed it completely

[ecrabb]

I had a similar issue when I first bought my car. Grabbing the brakes fast or releasing them after I stopped caused a minor clunk and a "twitch" in the steering wheel. FCABs fixed it completely

That sounds exactly like my issue. Thanks!

I can do the front suspension when I have the car up on stands getting the wheels resprayed and new tires on.

Off to YouTube to learn the process.

Cheers,
SC

[Simmsled]

Get Z4M FCABs.

They are perfecto.

[BCS_ZHP]

[emoji12]

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What the heck is that emocon boss man, why not just the laughing one. I farted in public on that one, you guys covered it up and didn't beat me too hard that day ( probably just because I was the source of food & drink, lol), but a definite screw up on my part and hopefully putting it out there will keep others from repeating the mistake.

[fredo]

What the heck is that emocon boss man, why not just the laughing one. I farted in public on that one ...

LOL ... I wanna know as well. I've seen those emoticons in some other posts. :dunno

[ecrabb]

Just confirming... I don't need to replace the control arms themselves; just the bushings, right?

Any bushings I should do on the rear end at the same time? I could be imagining it, but I feel like there's just the teeniest, tiniest bit of change in the track of the car when I go from throttle-on to throttle off.

I can be pretty certain none of this has been done on this 42,000-mile car. I just feel like anything rubber could be replaced... It's all going on 12 years old after all.

Thanks!!!

Cheers,
SC

[ecrabb]

Hey, I answered my own question for once! Reading here:
http://www.rogueengineering.com/rogue/S_BUSH/RE_RTAB.html


Problems with Factory Mounts
The factory BMW RTABs (Rear Trailing Arm Bushings) are a very soft material to provide the quietest, most comfortable ride possible. Because of this, we have seen factory mounts require replacement in less than 50,000 miles and 3 years. On modified vehicles, expect them to require replacement sooner.

Are your bushings already shot?
A simple test to determine if the stock rear trailing arm bushings require replacement is driving the vehicle in a straight line. While in gear, under full acceleration, does the car pull to one side? Additionally, under full, firm application of the brakes, does the car pull again? If you answered yes to either one, the bushings probably require replacement.

After reading that, I'm even more convinced. It's not a major problem at typical or even higher highway speeds, but I can see if you were at 120 and had to get into the binders hard, it could get interesting. I'm a little surprised it's so noticeable (if subtle) with only 42k on the clock.

So, anybody done FCABs and RTABs lately that has a favorite source because they're happy with the results? There are so many options and I'm just not clear on what I should use.

Cheers,
SC

[TristanHunter]

Just confirming... I don't need to replace the control arms themselves; just the bushings, right?SC

CAs shouldn't need replacement unless there is play in the ball joints or the rubber boots on the ball joints are damaged (in which case they would probably be making noise). At 42k miles, they should be OK; I'm at 145k on the original CAs and they still haven't worn out.



So, anybody done FCABs and RTABs lately that has a favorite source because they're happy with the results? There are so many options and I'm just not clear on what I should use.

Echoing Simmsled: z4m offset FCABs are awesome. They're solid rubber (oem are gel filled i think), so they last last longer. They'll also increase your caster angle a little, which improves turn-in and stability at speed and gives slightly heavier steering.

[BMWCurves]

CAs shouldn't need replacement unless there is play in the ball joints or the rubber boots on the ball joints are damaged (in which case they would probably be making noise). At 42k miles, they should be OK; I'm at 145k on the original CAs and they still haven't worn out.



Echoing Simmsled: z4m offset FCABs are awesome. They're solid rubber (oem are gel filled i think), so they last last longer. They'll also increase your caster angle a little, which improves turn-in and stability at speed and gives slightly heavier steering.

I bought Z4M FCABs for the reasons Tristan mentions but haven't installed them yet. I'm still unsure what I'm going to do for RTABs, but in my suspension refresh thread (link: http://www.zhpmafia.com/forums/showthread.php?16182-Help-with-Suspension-Refresh-at-50k-miles-10-years) I decided to wait and see how Slater likes these sealed spherical RTABs he got from Bimmerworld. If he isn't satisfied I'll probably grab M3 or Z4M RTABs because of their increased longevity and mild increase in stiffness and pair them with limiters, probably from Vorshlag.