Torque converter about to fail?

[BC00]

Hi guys,

Strange things started to appear with Stinger 3.3T.

Enormous amount of vibration/shudder appeared twice. Was driving very easily between 40-60 mph. Experience like driving on very rough road or like having a blown tire. Both times I gently stopped, put in parking, went around the car checking wheels and started driving again. Vibration was gone. Scanner shows no codes, neither misfires, nor powertrain.

Did anyone experience similar symptoms? Possible that torque converter is about to fail? If so why there are no codes?

 

[BC00]

Update:

Besides enormous vibration there is similar sound to banging, looks like it firstly comes from the rear end and after a while spans across all car.

Vibration/banging looks not to be dependent on speed. Gears up/downshift normally.

 

[HolyCarp]

Hi guys,

Strange things started to appear with Stinger 3.3T.

Enormous amount of vibration/shudder appeared twice. Was driving very easily between 40-60 mph. Experience like driving on very rough road or like having a blown tire. Both times I gently stopped, put in parking, went around the car checking wheels and started driving again. Vibration was gone. Scanner shows no codes, neither misfires, nor powertrain.

Did anyone experience similar symptoms? Possible that torque converter is about to fail? If so why there are no codes?

Hey man, sorry you're dealing with that, sounds super unsettling. I’ve been around a few cars that showed similar symptoms and here’s a list of most likely possibilities based on what you described

Driveshaft or CV axle issue – A bad u-joint or CV joint can cause serious shuddering and banging, especially if it’s starting to bind or about to fail. The fact that it comes and goes could point to something in the drivetrain binding under load and then resetting when you stop.
Center support bearing or carrier bearing (especially with AWD models) – These can make it feel like you're driving over rumble strips when they go bad. Vibes can echo through the whole car.
your Torque converter– Yeah it could be failing, especially if it's locking up weird or slipping under light load. But usually when a converter starts dying, you'll get codes eventually—P0741, P0744, or even transmission temp warnings. The fact that you’ve got no codes or slipping at gear changes might point away from this unless it's early stages.
Trans mount or engine mount failure – If one’s completely toast, it can make the drivetrain shift and thud, causing momentary banging and vibration that disappears after things resettle.
Diff or rear subframe bushing issue – If that banging really is coming from the rear first, maybe a rear diff mount or bushing gave out or is about to. Especially on hard decel or load change.

If it’s not speed dependent and feels like it just hits out of nowhere, I’d lean toward something mount or driveshaft-related over the converter for now. Might be worth jacking it up safely and checking for play in the driveshaft, axles, and rear diff area.


Let us know if it happens again or if you can feel it building up to the event. Hope it’s something simple

 

[BC00]

Thank you very much for your in-depth insights, HolyCarp,

Unfortunately I can not provoke these symptoms driving in harsh way, more load to the rear doesn't do anything. The car is silent when making turns too. I think bad CVs will make some noises.

Yesterday mechanic went underneath the car, nothing suspicious.

In recent days I drove 200 km, but experience was normal. Both previous times vibration/banging came from nowhere when I was driving very easily.

Could you tell me please what are parts number of center support bearing/carrier bearing? I have MY18 AWD.

 

[Thomby]

Before you start swapping parts, it's probably better to narrow down the source. You mention it happening while driving at 40-60mph.
- Were you in gear and accelerating, or steady cruising?
- Does pushing or releasing the accelerator change it?
- Does shifting into neutral make it stop?
- Does steering or braking change it? What about "leaning" the car to one side or the other while it happens?
- Is it tied to engine speed or wheel speed?

If it's downstream of the engine, you can put the car up on 4 jack stands and see if there's any free play at the wheels, suspension, diff, or driveshaft.

 

[BC00]

Before you start swapping parts, it's probably better to narrow down the source. You mention it happening while driving at 40-60mph.
- Were you in gear and accelerating, or steady cruising?
- Does pushing or releasing the accelerator change it?
- Does shifting into neutral make it stop?
- Does steering or braking change it? What about "leaning" the car to one side or the other while it happens?
- Is it tied to engine speed or wheel speed?

If it's downstream of the engine, you can put the car up on 4 jack stands and see if there's any free play at the wheels, suspension, diff, or driveshaft.

-Hard to remember my exact foot connection with the throttle pedal. Was driving in constant speed and this appeared;
-No connection with throttle pedal;
-Haven't tried;
-No connection with braking and steering. There was no feel of pulling car to one side;
-No connection with car's speed and RPMs

 

[Thomby]

-No connection with braking and steering. There was no feel of pulling car to one side;
-No connection with car's speed and RPMs

If the motion of the car caused it, it has to be tied to something, whether that's engine, wheel speed, brakes, or something weird like wind. What was happening when the vibration/shudder stopped? Did anything change when you released the throttle, did it stop as you were coasting down below a certain speed, did it continue until you braked...?

 

[BC00]

If the motion of the car caused it, it has to be tied to something, whether that's engine, wheel speed, brakes, or something weird like wind. What was happening when the vibration/shudder stopped? Did anything change when you released the throttle, did it stop as you were coasting down below a certain speed, did it continue until you braked...?

It continued till I stopped. Put into parking and left engine running. Car moved normally and all symptoms were gone. No, it cant be wind for sure

 

[Thomby]

It continued till I stopped. Put into parking and left engine running. Car moved normally and all symptoms were gone. No, it cant be wind for sure

Does it repeat under certain conditions? The next time it happens, I'd note the specific conditions, and see if throttle, brakes, or steering/lean change anything, shift into neutral and see if it continues while coasting down, etc. The goal being to tie it to the drivetrain or not, upstream or downstream of the transmission, etc.