Ok recently my '05 GT with 33K miles has started to physically feel 'rough' while driving. I want to call it a vibration, but its important to understand its a constant feel and not a "clang clang clang" obvious feel. Its soooo constant and fast. It basically happens throughout the car. Its nothing specific, its just something is vibrating the whole car.

It happens with RPMs. The lower the rpms the lower the noticeability, and it increases with RPMs.

It happens in drive and while sitting still, completely based on RPMs.

The clutch cover which had a TSB for missing bolts is already completed, I have the bolts for a few years now.

The TSB for exhaust hangers on the tranny crossmember is not needed. I banged on them with a hammer, they don't budge at all.

I'm questioning the rear muffler mounting.... But its never been a problem before?

I had issues with engine mounting after my shorty install, as I left a few bolts out of the motor mount bracket. I put them in, and the problem didn't start until later.

Theres definite 'whirring' going on below the shifter, around the tranny/spydershaft mounting area, and clunking in the hurst from the tranny (not badly, and maybe nothing new)

I've banged on the entire exhaust with a hammer but can't seem to get anything from it...

Any ideas?

Whats important to understand is the vibration is not a well defined CLANG CLANG CLANG at all, its an extremely constant and extremely fast vibration that basically gives the car a rough feel, rather than seeming like something is wrong. The car used to feel solid, with the only thing you hear and feel coming from the back from the tailpipes. Now its like its happening throughout the whole car (while still hearing the exhaust out the back).

 

Does it only happen when you're moving and/or in gear? Or does it also happen in neutral? If not, you can rule out the driveshaft and probably the tranny.

I get the whirring in the tranny too. There's a TSB that says it's normal. I did the synthetic oil swap and it helped a bit.

Possible you have a bad/cracked engine mount?

 

Can't really help, but I gotta admit that it sucks to hear that your car has been giving you so much ish lately

 

True, but its all my fault anyways. Ford built a great car.

To the guy above... The sound follows RPMs, and it doesnt matter if its in gear moving or sitting in neutrel.

 

b

 

Keep hitting it with the Hammer, maybe it'll behave....

 

Well, by process of elimination, it's not anything gearbox backward as it does it in neutral sitting still, and it's almost definately NOT exhaust either. An exhaust rattle will peak at a certain RPM as it hits resonance which you don't mention it does.

Therefore it has to be something motor/clutch/input shaft related.

Does the clutch work well? If so, does the vibration come/go when you have your foot on/off the clutch?

If it only makes a noise with the clutch depressed it the release bearing.
If the noise is only present with the foot OFF the clutch, it's your gearbox input shaft.
If the noise is not related at all to the position of the clutch pedal, and your clutch works perfectly (ie, does not drag) then it's something motor related.

 

is this problem happening since the shorties or before?

 

+1