03 GT Rear Suspension noise(s)

[bobc83]

I've posted about this rear-end noise a couple times so I wanna try again and give an update. I will pre-appologize for the length but I am so tired of this I want to sell my mustang.

03 gt 5sp
MM extreme duty LCA's
Brand new set of stock UCA
polyurethane spring isolators
Eibach springs
new kyb shocks

Had the stock control arms and lowering springs for about a year and no problems at all with noise. I try to upgrade my rear suspension with a set of MM LCA's and a set of stock style UCA's with stiffer bushings from summit ( they were free from my brother and a bushing on one the original stock arms went out so I just replaced for the hell of it.) Also got the shocks from him and installed them as well.

I installed things mostly one at a time to make sure they worked correctly without any problems, like controls arms and spring isolators one week, shocks the next.

Everything was fine for a week or two and seemed like everything was breaking in just fine and then I heard some wierd noises. When taking off from a dead stop, or taking low speed turns(in my parking garage I can hear it really well turning around the corners) I hear a noise that sounds like a light pop / creaking sound. It def from the rear suspension but can't really pinpoint by myself. Maybe the best way I can describe it is when my suspension is got tension on it. I called the MM guys and they are very helpful with questions. They can't do much over he phone I understand, but they did point me to make sure the arms were lubricated well on the chasis end of the XD arms and I did just that, all checked out fine, even using their grease.
Around town the XD arms ride like a charm, its just that the noise is freakin embarassing. When on the interstate, which I travel frequently, I can feel a bad vibration. When I travel about 75-85 mph and let off the gas and the car is just slowing down I get a bad vibration that vibrates everything inside the cab area. I called MM again about that and they told me I shouldn't pick up any vibrations or noises like what I'm describing from just the XD arms. I really want super performance but I shouldn't have to sacrifice all this for just a good LCA/UCA setup, that's ridiculous. I checked on the website and with MM via phone several times before getting these arms to make sure they would NOT pick up tons of extra noises. (BTW - I went XD arms because for a month I had some cheap LCA's from summit that had poly bushings all around and I kept blowing out the same bushing on the same arm 3 times.) I was thinking maybe the XD arms were too much for my car but I'm afraid to go to a full poly setup again, maybe something wrong with my car? Please help me before I pull out my hair and buy a camaro!! ahhh!!! dont let that happen!!

 

[steve_stang2003]

Have you considered that the problem might not be related to anything you did and just a coincidence?

Have you checked your U-joints?
Your symptoms kind of match what happens when a joint is going bad.

Just a thought.

 

[bobc83]

What is the best way to check them? I put the car on the lift and took a look at them, they appear to be ok, and dont seem broken or unlubricated.

 

[steve_stang2003]

What is the best way to check them? I put the car on the lift and took a look at them, they appear to be ok, and dont seem broken or unlubricated.

You really have to drop the drive shaft to check them and at that point you might as well just replace them.
It's easy to do but I generally just bring the drive shaft to the parts place I use and they press the joints in for about $15.00 or so.

One thing you can do is put a couple of your freinds in the backseat and drive on a smooth road and see if this aggravates or helps the problem.
What this does is change the angle of the drive shaft which will either aggravate the problem or make it better.

I discovered this when my wife started complaining about our GM car vibrating and making funny noises when she drove it.
Every time I drove it the car was fine.

Then one day I picked up the kids and the car started making the noise and I figured it out that she generally drove with kids in the back seat and I generally drove solo.

Making sharp turns in a parking lot will also aggravate sick joints.

This may not be your problem at all but it seems you've done just about everything else.

 

[bobc83]

Has anyone had experience with the MM XD arms? I'm a noob so i'll just propose some things.....would they be hurting anything being bascically solid like the torque boxes? Could they be too solid not letting anything give? Those don't seem possible but I just hear the noise at low speeds either turning or taking off. It sounds like metal creeking too me.

 

[steve_stang2003]

Has anyone had experience with the MM XD arms? I'm a noob so i'll just propose some things.....would they be hurting anything being bascically solid like the torque boxes? Could they be too solid not letting anything give? Those don't seem possible but I just hear the noise at low speeds either turning or taking off. It sounds like metal creeking too me.

You are going to transfer more noise because of the harder bushings for sure, but the kind of noises you are describing sound odd.

Are you supposed to grease the bushings on those things when you install them like you do with sway bars?

Sway bars will creak, squeak and groan if you don't grease the bushings when you install them.

 

[SVT32VDOHC]

All poly bushings squeak over time. I didn't read all your stuff, or the replies, but grease those up every oil change, or after the car sits for an extended period of time.

 

[bobc83]

I bought new "heavy duty" U-joints today and going to install this afternoon to eliminate that possibility.

SVT- the XD arms don't have any poly bushings, just "covers" as I call them on the chasis side of the arm, they have been greased like no other.

 

[steve_stang2003]

I bought new "heavy duty" U-joints today and going to install this afternoon to eliminate that possibility.

SVT- the XD arms don't have any poly bushings, just "covers" as I call them on the chasis side of the arm, they have been greased like no other.

Grease them up!!!!
Haha!!

Well the U-joints certainly can't hurt anything and if they solve the problem, your in business.
If not you might try having a friend ride along side your car, or hang out the window and listen to see if he can localize the sound to one side or the other.

Another thing is if you can put up a sound clip sometimes that will help others with the diagnosis.