Ever since installing my UPR UCA/LCA's I have been having a loud loud thunking noise going over bumps and when a shift isn't super super smooth. It is coming from the rear end and is on both sides of the vehicle.

I installed the uppers first and didn't hear any noise. I then installed the lowers and had noise immediately.

The parts that I installed were all adjustable. The front joints of both sets were heim and the lowers have poly on the rear and the uppers have rubber. I put rubbers in the uppers because that was what Max. Mot. recommended.

I spoke with UPR and the guys there think that I am having deflection issues due to the rubber bushings since the rest of the rear send is solid.

Here are the things that I have checked/tried to remedy the noise.

Removed the quad shocks
Rear end aligned/ lengths of arms checked
Retightened all bolts
Checked for loose parts, all of which are tight

I can hear the noise when the car is parked and off and the e-brake on, and then jerking the car back and forth from the trunk. Thing is I can't tell if it is the uppers or the lowers making the noise, but am figuring it HAS to be them cause it is happening simultaneously on both sides.

What do you guys think? The guys at UPR think I need to switch out the rubbers for polys and the noise will be cured. I figured I would ask around and see what people think before I go spending anymore money on fixing this damn problem.

Thanks guys for any help.

ps. other suspension mods include springs and struts, and subframe connectors.

 

I'm going to agree with UPR. It is never a good idea to mix poly with rubber bushings. any flex will be tranfeed to the weakest link. And in your case it is the rubber bushings. And it is more than they can take

 

I don't see mix/matching rubber/poly/shperical as an issue, but would suggest you check the following. I don't recall the year of your ride, but though it was a New Edge...? If not... did you possibly buy '99~'04 LCA's an have a pre-'99 ride? The bolts for the LCA's are smaller diameter on them and would account for some "play" in the LCA's.

Without looking directly at them and checking it out, I don't know what else could be at the moment.

Jazzer

 

Car is an '03, sorry about that.

Well I ordered new bolts. Going to put them in, see if that cures the issue. If not....I guess I'll try the poly bushings.

If that doesn't fix it.....I don't know.

Here's a vid.... the noise that sounds like popcorn is the noise. It isn't quite as harsh as it sounds (at least on my computer it sounds real harsh) in the vid, but my phone did a much better job of picking it up than I expected....

 

Boy..... something sure sounds loose, but seems a second person to be underneath the car while you do the hippy-dance inside will help to track it down. This may be completely unrelated to the suspension work, but failure of another part at the time of your work. It could also be something on an exhaust braket loose, I just don't know.

The bolt issue to which I refer, is that pre '99 Mustangs used smaller bolts and if you were to put a '99 LCA, there would be slop around the bolt that passes through the bushing on the axle side. Since you have an '03, this is not the issue, so is a mute point.

Jazzer

 

Well. Finally installed poly's in the diff housing. Sure enough, noise gone. Though there is a hitch in the rear end now when shifting. I'm wondering if driving on the rubber bushings and that clanking happening opened up a hole or something. Either way, that noise is gone and it is so nice ot not hear it.

Lesson learned. Do not mix soft/hard bushings.

 

i thought it was recommended not to use poly bushings in the uppers due to the fact that they have little deflection, which is needed for natural articulation with stock 4 link?

3 link ftw... lol

 

I am thinking along the same lines as my boy, zero here....

Please give us a link to the specific UCA's you have installed and the bushings you are now using, please.

Jazzer

 

Spherical and poly control arms will never be smooth and quiet like the factory rubber arms and bushings, you will expereince increased NVH, if you're trying to get a factory feel and sound level you aren't getting it with those control arms.

 

The NVH wasn't the issue, it was a definite knocking/thunking/something isn't right noise. Jazzer hopefully remembers the vid I posted. Don't know how the link is broken now.

I got the UPR Pro Series uppers
http://www.uprproducts.com/mustang-c...trol-arms.html
with the poly urethane diff housing bushings
http://www.uprproducts.com/mustang-b...-bushings.html

and UPR Chrome Moly Adjustable Urethane Lowers.
http://www.uprproducts.com/mustang-9...trol-arms.html