550 Groaning sound from passenger side rear when driving slowly

Hi Terence,

My 550 made the same light groaning noise a few years ago and it is getting loud nowadays when going at high speed. My mech said it is the differential that needs replacing. Also tried adding additive but didn't solve the problem.

I am thinking of getting it replaced. Anyone here has the tightening torque specs for the replacement of the differential? Appreciate your kind assistance.

Regards

 

Have you tried driving in a circle to see if the noise changes at all or becomes more constant? Maybe try doing figure 8's in a parking lot somewhere.
In a previous car I had wheel bearing issues and it would only make a groaning noise during turning because of the added force.

 

Does anyone else find this hilarious ? Of course a Ferrari us unhappy being driven to slowly.

Sorry Terrence I just couldn't help myself... good luck in finding the cause of this.

m

 

Sounds like a wheel bearing to me.

 

Mine have been a bit like that for the last half year too, but it is just there some times. Some days you can’t hear anything. I don’t understand why. My car has 157.000 kms. now. Can it have something to do with the anti-slip function in the differential? It comes for every rotation of the wheel/tire, not the rpms. of the engine. My gearbox oil looks as if it came out of a new bottle of oil. Do the transaxle oil use to get black? We decided not to replace it when I checked it at a workshop close by, but it has more kms. than the shift interval... Can it become condensation (water) in the oil from the hot/cold cycles and that make the lubrication more weak and less efficient? The level was also slightly over max on the dip stick. I want to fix this!!

 

Check both rear wheels, with the wheels of the ground. (2 post lift , or 2 heavy duty jacks with stands)
And if all is secure (be sure!!!), and you are brave enough, start the car to let the engine do the wheel spinning.
See if you can notice differences between the left and right wheel that way. Or hear where the sound comes from, middle right of far right.
Often a car with a wheel bearing that is on its way out, will spin more easily than a good bearing (resistance of the internal bearing grease).

And after using 1st gear, set the car into neutral, and see if the right wheel stops at around the same time as the left while slowly applying the hand brake.

This way you have more info we can discuss about.

 

When I do this on my car on jack stands, the wheels turn slowly even in neutral. I need to disable the ASR in order to stop the engine from «cutting off» even in neutral, so without traction control on, the engine run as it should and the wheels turn a bit slower than in gear. This is said to me to be normal. Same for a propeller on a boat... Normally on a car, when you turn one wheel around in the air while the engine is off, the one on the opposite side turn the other direction. On mine, the other wheels turn the same direction. I have never really understood why...!? Anyone here know why? Thanks!

 

Yes, when a car has a Limited Slip Differential, the wheel will turn in the same direction. This is normal for your car.
(cars without an LSD have wheels turn in opposite direction when one is turned).

 

Gosh, I dunno how much a rear diff replacement would cost, but I’d sure hate to do that and then find out it was a wheel bearing.

 

If there is a bad wheel bearing, one should think there would be play in it when you shake it in and out? Or is it normal not to feel any play even if it is bad...? Is it one bearing or two cone bearings? Two cone bearings use to be able to tighten at the center bolt to put more tention to them. Is thet the matter? Anyone knows?

thanks,
Erik

 

There shouldn't be any play when shaking the wheel, but it might not be reliable because bad ball joints would also have the same affect when shaking. I can't think of a simple test without the wheels being under some kind of load.

 

Yes this ^^^^ it’s true that many times you can locate a bad bearing through play, tugging, turning, listening. But what I’ve found is that this is hardly a definitive method, and many an experienced mechanic has misdiagnosed things because the unjointed/wheel bearing passed the tug test.

 

My last one did that but only when I lifted at higher revs, and it seemed to be in unison with the shock travel (at the bottom). No one could ever figure it out and I couldn't hear it from my side.

You can hear it in this video.

 

Mine is not like that. It is more like a little sound for each revolution of the wheel.