Help! Fishtailing on dry pavement?!

suspension

#1

Hi guys, I’ve got a 2011 Dodge Challenger SE Rallye Redline with 73xxx miles. Tonight while driving around, I suddenly started feeling the rear end begin swaying side to side lightly at 25-30mph. At first I thought I’d accidentally pressed the traction control button at some point, but no. The road I was on was completely smooth and there was no gravel/oil/etc to warrant this sudden behavior.

As I was trying to find a safe place to pull over, the swaying began getting worse and worse. It felt like I was driving on an ice rink. When I did regain control of the car, it seemed to drive “crooked”. It felt like the car suddenly threw itself out of alignment very badly at that very moment. I had to fight the steering wheel to stay in my lane.

As I accelerate from a dead stop, the wheels in the back seem to drag a bit, then the weight in the back feels like it shifts slightly to the right. I checked all 4 wheels to see if one had gone flat or was low on pressure, they were all fine.

When coming to a stop, there’s a light vibration (unlike what you’d normally feel from bad rotors) it felt like a droning grind when you lay on the brakes and roll at 2-3 mph.

I had my rear brake pads and rotors replaced about a month ago. It was driving great until about an hour ago, and kept getting progressively worse on my crawl home.

I did some research and came across Rear Cradle Bushing Failure, but it seemed to occur in the 2010 and earlier Challenger models from what I’ve read so far. It’s probably happened in newer models, but I’m not sure. But with the bushing failure, there seems to be no warning like I have now, and no one described a fishtailing/swaying effect from it.

Could the shop have installed the rotors wrong somehow, or put the tires back on incorrectly? I’m going to have it towed to a dealership this weekend, but I’d just like some input from others in the meantime, thanks in advance.


#2

First thing I would check is that all the lugnuts are tight. If the mechanic forgot to tighten one wheel it could take some time to loosen enough to cause a problem.

2nd. if your car has a rear sway bar…one of the links may have snapped. crawl under enough to check the rear end and you may find the problem.

Check those lug nuts before you drive it again.

Yosemite


#3

If Yosemite’s suggestions don’t find the problem, check the back brakes, especially the right one. Check to see if it’s sticking or seized up.


#4

I suspect your limited slip differential has a failure. Low fluid or old fluid may have contributed to a clutch or bearing failure. I don’t think the car is safe to drive. Getting a tow is the right call.


#5

While the other theories are good ones, I believe that Uncle Turbo is on the right track by suspecting a problem with the Limited Slip Differential (LSD). The severity of the problem suggests to me that this is a failure within the LSD–assuming that the car is equipped with an LSD.


#6

yeah, LSD makes things seem to sway back and forth sometimes…

but seriously, the car is unsafe to drive until you solve this problem


#7

My first guess, this is what our esteemed Car Talk Forum colleague @Yosemite suggests, the wheel lug nuts have come loose, and a wheel is wobbling hither-nether.


#8

Wow…Esteemed…I’m flattered!!! @GeorgeSanJose

But I hate to admit, I knew that one from experience.
Replaced the U-joints on a old ranger that I had, years ago. I had the rear tires off and when I put them back on, I must have only tightened the drivers side lug nuts.
The next day I went about 30 miles and started to feel a bad vibration. Checked the lug nuts and, Yep I forgot the passenger side. I probably got distracted by a pretty girl or something.

Yosemite


#9

IIRC the Challenge SE was the V6 model. It only came with an open diff.


#10

Wow thank you so much for the input guys! I haven’t driven it since the problem showed up. I won’t be hearing back from the dealer until Monday though, so I’ll update with their findings asap. I’m really hoping it’s a simple fix like loose lug nuts! :slight_smile:


#11

Considering the recent work on the brakes one has to consider the possibility of lugs being left loose.
Another possibility is a brake caliper sticking. The car is a bit young and how low enough miles that a caliper piston should not be sticking but a caliper hanging up on a slide is feasible.

Cleaning and lubing caliper slides should be part of any brake job but many times this chore is neglected.