Hey everybody my Cobra is experiencing horrible vibrations when going above 60MPH, sometimes worse than others. From the little research that i've done it is a common problem. Also I have read and heard from friends about a recall where the 99 Cobra was not making the advertised HP and were being fixed at no charge. Is this accurate? and if so what do I need to do?
99 Cobra - Bad Vibration at highway speeds! HELP!
- Thread starter mcastro713
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cradicg
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Another possible option...
I had a car that vibrated badly at high speed due to one tire being worn out more than the others. Check your treads. This is the first I've heard of this being a common problem, and mine sure does't vibrate that bad (I have poly motor mounts).
As far as the 99 recall, if it has not already been done, you are SOL having Ford fix it. I called SVT (they can tell you if it was done) and since it is not a safety issue, the recall coverage expired when the factory warranty ran out. Check out this site for all the details on the recall and what to look for.
http://mysite.verizon.net/txsnakecharmer/tech.htm
If it turns out yours was not fixed, the only hard part to get ahold of will be an intake. If you can't find a "fixed" one, SHM will fix yours for big $$$, and Boss 330 racing I think also works on them. I have dealt with Steen Racing and Jason can also P&P your intake. The exhuast and tune can be done almost anywhere.
mcastro713 said:
I had a car that vibrated badly at high speed due to one tire being worn out more than the others. Check your treads. This is the first I've heard of this being a common problem, and mine sure does't vibrate that bad (I have poly motor mounts).
As far as the 99 recall, if it has not already been done, you are SOL having Ford fix it. I called SVT (they can tell you if it was done) and since it is not a safety issue, the recall coverage expired when the factory warranty ran out. Check out this site for all the details on the recall and what to look for.
http://mysite.verizon.net/txsnakecharmer/tech.htm
If it turns out yours was not fixed, the only hard part to get ahold of will be an intake. If you can't find a "fixed" one, SHM will fix yours for big $$$, and Boss 330 racing I think also works on them. I have dealt with Steen Racing and Jason can also P&P your intake. The exhuast and tune can be done almost anywhere.
I called the 800-FORD-SVT line and had them run my VIN # Turns out my car did have the upgrades done back in Oct 2000. As for the vibration, I checked my tires and the rear passenger side tire is more worn out than the rest. I am getting new tires and wheels this weekend. I am going for the 17x9 in the front and 17x10.5" in the rear. Do you recommend the 305 or the 315. I am also stuck between the Nitto 555R and the Falken 452.
I own a 2001 Cobra and previously owned a '99. Actually I think I was the first owner to post a message about the vibration and get the ball rolling toward Ford's finally recognizing the problem. You might be too late, but in '99 Ford issued a TSB where they replaced the transmission, driveshaft and differential with matched and balanced units. It helped with the vibe, but didn't eliminate it. Because of the balance problem and the low horsepower, Ford gave all of us '99 SVT owners a free leather jacket (wow). The 2001's still had the problem, especially if you put in a taller gear. Of course, you might have some other balance problem, but I assume you've checked the obvious.
The problem is that pinion runnout and driveshaft balance tolerances are OK for a live axle, but they are too large for an IRS system which tends to transmit vibration to the body. The easiest fix is to use driveshaft balance to offset the pinion runnout. That's essentially what Ford did with the recall. You might want to get your driveshaft balanced before you try this, but I didn't find that necessary to eliminate 95% of the vibe.
Buy a cheap dial indicator from Harbor Freight, set it up securely under the diff and find the point of maximum axial (vertical) runnout on the pinion flange. Then put 2 hose clamps around the driveshaft with the screws positioned opposite eachother. It doesn't take a lot of weight to dial out the vibe, so instead of starting with the screws up around 95 and 265 degrees, start at something like 135 and 225 degrees. You need to do a bunch of road testing, but you'll rotate the clamps away from the point of max runnout (keeping the screws opposite eachother) until you decrease the vibration to an acceptable point. Adjust the clamps, road test, repeat....
We worked over this issue for a long time back in '99-'01 before we finally settled on this fix.
This url will take you to a good explanation of the problem and another approach at fixing it.
http://www.lx.net/jlynch/fieldbalance_r1.html
Good luck.
Jeff
The problem is that pinion runnout and driveshaft balance tolerances are OK for a live axle, but they are too large for an IRS system which tends to transmit vibration to the body. The easiest fix is to use driveshaft balance to offset the pinion runnout. That's essentially what Ford did with the recall. You might want to get your driveshaft balanced before you try this, but I didn't find that necessary to eliminate 95% of the vibe.
Buy a cheap dial indicator from Harbor Freight, set it up securely under the diff and find the point of maximum axial (vertical) runnout on the pinion flange. Then put 2 hose clamps around the driveshaft with the screws positioned opposite eachother. It doesn't take a lot of weight to dial out the vibe, so instead of starting with the screws up around 95 and 265 degrees, start at something like 135 and 225 degrees. You need to do a bunch of road testing, but you'll rotate the clamps away from the point of max runnout (keeping the screws opposite eachother) until you decrease the vibration to an acceptable point. Adjust the clamps, road test, repeat....
We worked over this issue for a long time back in '99-'01 before we finally settled on this fix.
This url will take you to a good explanation of the problem and another approach at fixing it.
http://www.lx.net/jlynch/fieldbalance_r1.html
Good luck.
Jeff
cradicg
New Member
Wow, now I know!
I stand corrected. I never heard that Ford "officially" had a drive train vibration issue until now. My car does vibrate, but it is not what I would classify as "horrible" like mcastro713 stated.
After replacing my blown T45, I attributed the increased vibes to the TKO600 being a hard core tranny. Since then I have had the motor replaced, 4.10 gears installed, Steeda IRS subframe brackets, MMS full length subframes, and every bushing and mount switched to poly. The vibes are worse now, but still not "horrible". Was the IRS the main culprit in the vibes?
There is nothing original left in my drive train but the IRS. Pressing the clutch stops the tranny and driveshaft from spinning right? With the clutch pushed all the way in and removing the accessory belt from the front of the motor it still vibrates at higher RPM. Could my brand spanking new Ford crate motor be imbalanced? The motor does not shake at all in the engine bay, but the whole car vibrates around it.
I stand corrected. I never heard that Ford "officially" had a drive train vibration issue until now. My car does vibrate, but it is not what I would classify as "horrible" like mcastro713 stated.
After replacing my blown T45, I attributed the increased vibes to the TKO600 being a hard core tranny. Since then I have had the motor replaced, 4.10 gears installed, Steeda IRS subframe brackets, MMS full length subframes, and every bushing and mount switched to poly. The vibes are worse now, but still not "horrible". Was the IRS the main culprit in the vibes?
There is nothing original left in my drive train but the IRS. Pressing the clutch stops the tranny and driveshaft from spinning right? With the clutch pushed all the way in and removing the accessory belt from the front of the motor it still vibrates at higher RPM. Could my brand spanking new Ford crate motor be imbalanced? The motor does not shake at all in the engine bay, but the whole car vibrates around it.
cradicg
New Member
Bigger is (sometimes) better
I am a fan of wide tires myself. The only snag is that not all manufacturers produce tires that are exactly the same, even though they are sized identically. Brand "A" may produce a 305 that is just as wide as Brand "X"s 315. If you can find a picture of the tire you like mounted to the same rim you will be using, go with the more attractive looking fit. Otherwise, a bigger contact patch in the rear can't hurt.
mcastro713 said:
I am a fan of wide tires myself. The only snag is that not all manufacturers produce tires that are exactly the same, even though they are sized identically. Brand "A" may produce a 305 that is just as wide as Brand "X"s 315. If you can find a picture of the tire you like mounted to the same rim you will be using, go with the more attractive looking fit. Otherwise, a bigger contact patch in the rear can't hurt.
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