Trying to fix vibe.. what do they replace in the rear?

When they replaced my pumpkin they supposively checked the pinion angle. What do I tell them?

 

They said they have no clue what to do and they will continue to call SVT.

 

I work at a dealership and have replaced my driveline and pumpkin with only minor improvement, probably from the MM irs bushings changing the pinion angle?? I will check my angles with a gauge soon.

 

My car has a new diff, new driveshaft, in neutral the motor spins freely and without vibe from idle through 6000rpm, but I still have a 'fizz' vibe from around 1900 through 2300 rpm.

I have a full Bassani and X-pipe.
I think my clutch is near the end of its useful life (33K miles)

Any ideas what causes a consistent vibe near 2100rpm but nowhere else?

 

I just got my cobra back from the dealership, and no more vibration. They replaced my driveshaft and then indexed the new one before re-installing it. Silky smooth now, I am very pleased.

 

It was the driveshaft. That sounds like the most logical answer.

 

Do you have a stock exhaust?

 

hmwave,

I do not have a stock exhaust. I have a UPR x pipe and magnapacks with 4 inch rolled tips. I do believe that indexing your driveshaft cures alot of the problem. The performance tech that worked on my car is very knowledgable, first they tried to index my original driveshaft that came on my cobra from the factory, and it mad it worse they said. They then installed a brand new driveshaft, and indexed it and checked my pinion angle, and problem solved after that. Now, my vibration problem only arose when I installed my 4:10 gears, I never had any vibration issues at all before the gears. I just thought I would throw that in there.

 

MY CAR IS AT THE DEALER RIGHT NOW, THEY REPLACED MY DRIVESHAFT, VIBE STILL THERE, NOW THEY ARE PULLING THE REAR APART I'LL KEEP YOU GUYS UPDATED epper: :banana:

 

The vibe was fixed with a new driveshaft and reindexed. Smooth up to 120mph.

 

Getting My Car Back Today From The Dealer They Replaced The Driveshaft And Rear Housing/diff/gears, They Said The Back Lash On The Gears Was All Sorts Of Messed Up Almost 6th Of An Inch Out On Some Spots, I Guess We'll See When I Pick It Up Later

 

Man I wish I had the luck you guys do. I have done all of this and still nothing. The only thing left is to try different bushings.

 

My vibe is very dependant on the road surface......... it goes from zero to rear view mirror vibration depending on the type of road. This makes me suspect the tires

 

I took my D/S after the vibe got worse and worse. Druing the removal, I removed 2 of the 4 bolts holding the shaft in place by hand. This worried me to the extent where I was just fed up with Ford's crap about not being to test the car at 80mph.

So I'm stuck between getting a steel driveshaft made to measure or just buying an OEM aluminum shaft from Ford racing and be done with it. Ford sucks and their customer service is bad.

 

dealer now say's my car should be done by friday :mj:

 

VIBE IS STILL THERE, REPLACE R&P, DIFFERENTIAL, DRIVESHAFT, HOUSING. NOT SURE WHAT TO DO NEXT, MAYBE TRANS RELATED????? I'M VERY ANGRY I WANT TO MOD MY CAR, I HAVE SO MUCH STUFF FOR IT. :cuss: :fm:

 

I feel for you and all your troubles. I do like your sig though, it is hilarious and made me laugh.

 

try removing the drive shaft, and having it balanced externally by a drive train/driveshaft specialist

 

Let me know if you figure it out. I have not found anything either.

 

Then advertising 390hp and top speed of 160mph or so should also be illegal :uh oh: