blittle

They are replacing the "control arm" and doing a recommended 39,000 mile trans. drain and flush. The control arm is part of a known issue...at least on the 07's.... a very annoying "clunking" metalic sound coming from underneath the the left front floor area. Apparently the bushings don't do their job once the vehicle gets up in mileage. The only solution is replacement of the control arm soooooo.... Hope that does it because the sound it makes is sort of what you expect from a 10yr. old pickup truck!!

StevethePilot

Huh. I wonder if they did that on mine without me realizing it. I never had the clunk and I'm at 55K+ miles on the 'aught-seven 320.

STP

Roujin

Do you guys mean the Driver's side? My wife is noticing something on the front passenger's side. Thanks

blittle

It could happen on either side and most likely they won't do the work UNLESS you are having the problem. It is a fairly expensive piece of warranty work....the service bulletin calls for them to 1st try squirting a type of wax in the bushing area to see if that cures it.........it did not on mine.....so the next step is replacing the control arm.........just got a call from the dealer....car is ready and noise is gone

MB500

What about the trans. drain and flush? Is this something that you are getting done under warranty? By the way, my 07 is also having that 'clunking noise'. First I thought it was the brake caliper. The car is now at the shop and they are trying to put wax to see if it cures the problem. Isn't wax going to wear out over time? Should I insist on replacing the control arm?

oknish

Good to hear about succesful repairs, blittle.

Can you describe what this "clunking" sounded like? Was it at low speeds or all the time? I am also hearing a rattling/clunking from Front left at low speeds.

MB500

I just received a call from my dealer when they told me that appropriate grease (wax) was applied and 70%-80% of clunking noise is now gone. They are keeping the car over night and going to test drive it in the morning. I asked my adviser if the noise is going to come back over time but he assured me that most of the time the issue is fixed with wax. Do you guys buy it? How can the noise be 80% gone? It's either there or not.

Oknish, the clunking noise is most noticeable at lower speeds around 30-40mph. I could hear it as I pressed brake pedal. Sounded like brake caliper was hitting brake pad. Almost like a clunk/ping type of noise. Once you hear it you will know for sure.

blittle

Yep....I thought brake caliper as well! The wax was an immediate failure on mine. Mechanic took the vehicle out to test drive and there was no difference......noise was still there. My mechanic is a personal friend of mine.....told me that the wax MIGHT cure the problem but he had his doubts from the beginning. Since replacing the arm is not what MB specifies on "first try" I don't think they will do if for you unless the wax fails. The trans drain and flush is an MB suggested service at 39,000 miles. Mechanic highly recommends it on the 7speed trans. He said this trans. is "fussy and really likes to be clean." He knows his stuff......I do what he says.

blittle

You guys are dead on......there is no such thing as 70% gone.....it's either there or not. Also correct is that it is most noticeable at lower speeds when applying the brake and then somewhat upon acceleration after brake application. Sounds like groaning or clunking metal against metal. Mech. told me that it makes the noise as the weight of the vehicle transfers from back to front on braking. I don't think wax is going to stop an issue like that..... at BEST it might hide it for a while. But wax is no match for the weight of a GL! Mech. also said "no MB should sound like that!) I agree!

blittle

Sounds like you might have it...............

MB500

My dealer has already replaced control arm and will be replacing ball joint to address the clunking noise issue. Just FYI.

blittle

ball joint as well?

MB500

Looks like it. It's on order and should come in on Monday. Control arm has been installed and I cannot hear any clunking noise at all. The old ball joint looks fine to me but I'll let them go ahead and change it anyway. Those joints go out sooner or later.

blittle

This is probably obvious....but....they should do an alignment when all done. The alignment on mine was covered as part of the warranty work.

MB500

Very good point. No mention of alignment on my paperwork yet. I will ask if they were planning on doing it when they changed ball joint.

Thank you for the tip.

MB500

The dealer refused to do alignment under warranty as it claimed that it would not be necessary after changing the upper control arm and the ball joint. I was told that the only time MB would do alignment is when they change the lower control arm. I spoke with three different people at the dealership -- my adviser, MB warranty rep and the shop foreman and they all told me same story. I was also offered to get alignment for $159. What do you guys think? Are they just giving me the 'run around'?

blittle

Well........I don't know for sure about that one BUT in my case it WAS the lower control arm that they replaced. It may be that they are right....upper control does not have an impact on the alignment. I'll check with my mechanic at my dealership......he will give me the straight scoop!