Hey Richmod, how did the driveshaft work out for you?

 

They still have the car. Should be ready tomorrow. I'll post when I get it.

 

Service director just called. Driveshaft is in. His exact words - "So far we've made it worse". They're gonna try to get it right, and if they can't, the Ford engineer is coming for a look see. If he can't get it right, I'm asking for anew car.

 

Good luck, I'm taking mine in next Wednesday to give it a go at another dealership.

 

Good luck to you as well. This is already my second dealership. The car's been in for service about 27 days and counting, had 4 TSB ring and pinions, one whole new rear diff and axles assembly, new driveshaft, all new related bearings, and yet it still vibrates and whines. I'm done with the dealers. The wierd thing is, I drove another new 2007 GT off the lot wth the service director, and it had the same vibration, and WORSE whine on decel. He told me he has since driven 4 more and they ALL had varying degrees of whine and vibration. Thing is, mine had NO vibration and NO decel whine when new - just a slight hum on accel. It was only after they did the first TSB when the decel whine started, and after the 4th TSB that the vibration started. Even a whole new rear end didn't fix it. Makes me wonder if Ford started using crappier parts and now this vibration/whine is a "normal" characteristic for cars built after a certain date.

 

Just an update - service director called. Said no matter what they did, the new driveshaftvibrated worse than mine. He said he's gonna try swapping driveshafts with another GT on the lot. If that doesn't work, he's putting mine back on and calling for a Ford engineer to come look at it.

 

There's a few possibilities:

1. Tires out of balance or resonating at that speed.
2. Driveshaft out of balance
3. Resonant virbration in the drivetrain at those speeds.

If it goes away when you exceed that speed range, it probably isn't the driveshaft or the tires as those would only get worse as the speed increases.

 

No vibration here but I have 1800 miles and runs great! Great explantion by PW

 

Man, it's not looking good for us . I hope you have a more timely response from the for engineer than I am.

I'm starting to think it has nothing to do with the driveshaft. When things that rotate are out of balance, they usually cause harmonics/vibration at a specific RPM. One would assume that if we are all having the problem at the same exact speed, then our driveshafts would have to be spinning at the same speed. However, we all have different rear ends, as I have a 5sp, and I've read where automatics have the same problem (don't know what you have Richmod). This would mean our DS is spinning at different speeds. I think it would be too much of a coincidence that they would spin at different speeds and cause a vibration at the same road speeds. We know the vibration has to be aft of the transmission ouptut shaft, as the vibrations are independent of rpm or gear selections.

I'm going to try and take my car to a tire shop with a Hunter GSP9700 and have all 4 tires completely rebalanced. I tried swapping rear to front, and side to side to see if I could notice a change, maybe feel it in the steering wheel, but I had no luck with that. However, I'm running out of patience and at this point will try anything.

 

It's notthe drive shaft.

Anyway, just got the call from my service guy and said the car is ready to be picked up. The put another ring and pinion set back into the rear and I'm back to 3.31 gears again. Can't pick it up til Tuesday.

Oh, one more thing!!! I got a new front windshield installed. While they weretest driving it and a rock hitand cracked it.

Let ya know the outcome when I test drive it.