Vibration

[ugasouthernpride]

AND...

did you first notice the vibes after the half shaft install?
I’m sure they’re high quality ... Overall, but they’re mechanical parts designed and manufactured by imperfect humans. Mistakes happen. It could be workmanship too.

Whenever you have a problem, always look back to the last good observable performance and work forward through any changes and:

NEVER modify a vehicle that has some problem or concern. Ever. You will amplify troubleshooting efforts.

Let us know what you find tomorrow.

I may be able to feel the vibrations in the steering wheel, but I cannot identify any oscillations.
A description of the entire car vibrating may fit, but it is most certainly felt in the seats.
I also am unable to identify any relationship based on engine RPM.

Sponsored

 

[smurfslayer]

I may be able to feel the vibrations in the steering wheel, but I cannot identify any oscillations.
A description of the entire car vibrating may fit, but it is most certainly felt in the seats.
I also am unable to identify any relationship based on engine RPM.

so it’s purely road speed then? if you’re at speed and go to neutral, the vibes do not change?

so no collisions, no large pot holes, one salient change - ‘aftermarket’(-ish) half shafts, and shortly after a vibration manifests.
This is clueful.

 

[ugasouthernpride]

so it’s purely road speed then? if you’re at speed and go to neutral, the vibes do not change?

so no collisions, no large pot holes, one salient change - ‘aftermarket’(-ish) half shafts, and shortly after a vibration manifests.
This is clueful.

im beginning to think there is noticeable movement at all speeds. It is difficult though because the car has a predictable shutter anytime a bump is encountered.
There is no doubt that a cyclical, predictable vibration occurs on the newly paved highway, which is very smooth with every other vehicle I’ve driven it on…but any minimal bump I encounter results in a shutter of the entire vehicle.
For example, when I feel the front wheels go over a bump, there is a predictable temporal relationship with a vehicle shutter that soon follows.
But, even at low speeds (ie 5-20mph) on what appear to be smooth roads, there seems to be a similar unexpected movement like a bent rim. Idk.

 

[dusman59]

I would check the run out on the half shafts that you had installed. It might not hurt to have a complete alignment.

 

[ugasouthernpride]

I would check the run out on the half shafts that you had installed. It might not hurt to have a complete alignment.

dealer has aligned the vehicle within the month. All in spec.

 

[dusman59]

OK alignment is good. What was the run out on the shafts. Run out has nothing to do with alignment. If run out is too excessive you will get vibrations. It will act similar to a bent shaft. Another place to check is the differential as when installing shafts one would have to go into it.

 

[steveo1960]

Have the original 1/2 shafts put back in and start from square one.

 

[smurfslayer]

Have the original 1/2 shafts put back in and start from square one.

THIS

I’ve never had an alignment cause a vibration, but YMMV

 

[ugasouthernpride]

THIS

I’ve never had an alignment cause a vibration, but YMMV

It would be a secondary cause.

 

[ugasouthernpride]

OK alignment is good. What was the run out on the shafts. Run out has nothing to do with alignment. If run out is too excessive you will get vibrations. It will act similar to a bent shaft. Another place to check is the differential as when installing shafts one would have to go into it.

I don’t have any way to test runout. That’s a great academic thought, but how can I test it myself? I do not run a precision machine shop and do not have a bench lathe. That is what the manufacturer does with quality control. This is why I paid 2500 for the half shafts…so someone would test the balance, concentricity and runout.

 

[dusman59]

A dial indictor on the end of the axle. Dealer should be able to preform. Even though you paid big bucks for someone to do their job doesn't mean things are good. Other option is reinstall what others have suggested. A vibration as you describe will cause other problems later on. Wish you the best in solving your problem.

 

[smurfslayer]

It would be a secondary cause.

How?

 

[ugasouthernpride]

How?

Misalignment can lead to a myriad of tire issues which can cause NHV.

 

[ugasouthernpride]

A dial indictor on the end of the axle. Dealer should be able to preform. Even though you paid big bucks for someone to do their job doesn't mean things are good. Other option is reinstall what others have suggested. A vibration as you describe will cause other problems later on. Wish you the best in solving your problem.

this would require either a setup on a bench or hanging the car in the air and mounting a dial indicator properly while the axles are installed and rotating.
I have been a tech and service advisor in a past life x 10 years. I have rarely seen such precision or detail done.
unfortunately, I have little hope of my dealers capability.

 

[24VertPP]

Do you have a resolution to the vibration yet? I also have a 24 GT convertible, performance pack, magnaride, active exhaust and about 7k miles. The vibration has been there since purchased as a new car. My vehicle also has an oscillating (roughly 5 second cycle) vibration at 70. The vibration is felt in the body as all the mirrors and seats visualy shake. The vibration is consistent no matter the road. I have road forced balanced the wheel assemblies twice and performed an alignment since I have the equipment at my shop to do so (no issues found). I would be very interested in an update. Does your vehicle have magnaride. I will be making a service appointment soon. Please keep us posted as I will do the same.

Sponsored