If you have aftermarket lower control arms or even if you don't, then it's very possible that the metal bar attached to the lower control arm nut is rubbing on the sway bar. When you tighten the lca bolt that bolts to the rear axle this nut spins till it makes contact. It's there so you don't have to put a wrench on the other side to stop the nut from spinning.

What I do is wedge a thick piece of flat steel between the nut arm and the sway bar, then once I torque it to spec, i knock the piece of steel out. On the passenger side it will wedge itself against the axle tube.

it makes a noticeable squeek on slow speed bumps, not going fast though, at least I can't hear it at highway speeds.

Wish i had a picture to show what I'm talking about.

It's called a flag nut and the flag part can cause a squeak if it's contacting metal.

 

Thanks for that! I'll look, but my squeak is opposite, at slow speeds I can't hear it, but at about 35+ is when I hear it

 

In that case I'd suspect the exhaust hangers rubbing on their mounts.

 

I had the most annoying front right suspension squeak over every bump. Installed Eibach springs and dampers and the squeak is completely gone! I'm thinking its the dampers.

 

My new 2013 mustang with 3900 miles was squeaking when I go over speed bumps. So, I took it in to the dealer and they said the rear stabilizer links were bad. They replaced them under warranty and no more squeaks

 

Awesome! Thanks for the update, pykim007.

Deysha

 

Last time I brought it in for rear 'squeaking' over bumps, they replaced the rear stab. Now it's back with a hollow rattling sound to go along with it.

 

Let me get this escalated to the customer service manager for your area, WesleyEng.com. Please, PM me with your VIN, dealer, mileage, full name, and best daytime number so I can help.

Deysha

 

I've had my car for 2 years and 3 months. When my car was just 3 months old, I started to get that annoying squeak over bumps. Long story short, my car has now been in 8 times for this squeak. I can't remember the order, but my front steering control arms were replaced (even though it was super obvious that the squeak was in the rear), bring it back, stabilizer links replaced, bring it back, bushings replaced, a couple other times, they just greased everything up and sent me on my way. After 15 months, one year ago, they replaced the shock. That made the squeak go away... until now. It's back. I will say, I have noticed that the squeak appears at this time of year, when it's cold and snowy. Could it be the cold? Could it be the sand and salt on the road? I don't know. The dealership took it out for a drive last week and it only squeaked once, so they couldn't figure it out. After I told them that when the shock was replaced, it seemed to go away for the longest period of time, they decided to order me another new shock, so my car is booked in a couple of days to go back. But, I just washed my car tonight (it was the filthiest it's ever been)... I sprayed underneath really good, and now it's squeaking nice a good. Which makes me happy because now the dealership will be able to diagnose what they "think" is the cause. I have less than 800km left my warranty, and all I ask is that they fix it. I don't care if they have to rebuild my entire rear end.

 

[QUOTE=CincyGT2009;7432945]Assuming it is the stabilizer bar bushings, what would you use to lube them and is there something that can be sprayed rather than disassembling everything?[/QUOTE
The stabilizer bars walk across the forward bushing until they rub on the bracket. I took them off and knocked the bushing back in. Then I welded straps on the other side to keep the bar from walking over.
Straps hold bushing in