Yet another vibration Question
 

Well, I just finished installing my new Aluminum Driveshaft and rear sway bar (which the previous owner removed), and now I suddenly have a vibration when my engine gets past 4k rpm in each gear. I never felt this vibration before I put the new Driveshaft on, only the one I felt when I went faster than 70mph. WTF??

My throwout bearing is starting to make noise again, so I am gonna have to replace it for the second time in 2 months. Could the TOB cause a significant vibration???
I also replaced the harmonic balancer about 3 months ago, so I am pretty sure that's not the problem.
If it's not the TOB, what else could cause it?? Also, does anybody make a better TOB than the one you get at Autozone or Advance??
Please help.

PS. Anybody else go to the NMRA World Finals?

you may have bought an improperly balanced driveshaft or the u-joints may be bad in it, i went to the finals on saturday, pretty damn awesome huh? did you get one of the driveshafts that they had just laying around in the swap meet? if so i bet that it is the cause, 99.9% of the time when you change or install something and something goes wrong, its because of what you changed, so try putting your old d/s back in and see if that fixes it, good luck

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88 Notch, B&M Ripper, 3.73's, Ported E7's, Explorer int. w/ ported lower, pulleys, 1.7RR's, BBK headers, off-road H-pipe, flowmasters, subframes, 65mm TB, March ram air ,MSD coil, U/L control arms, 155lph f/p, Crane Adj.FPR, Nitto drag radials, best 1/4--> 13.76@101.4 on a 2.17 60ft

The driveshaft wont cause the vibration in every gear at the same rpm, it will only vibrate at certain mph. What kind of harmonic balancer did you use? If it is the factory style check to see if the rubber is seperating again.The throw-out bearing shouldn't cause that vibration because it shouldn't be engaged all the time.


Good luck!!

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B.R.
L.X. 5.0 coupe
Cruise control,power mirrors,...and Thats it!
( except for the supercharger )

When I replaced the harmonic balancer, it was just a replacement from AutoZone. I hope it isn't that again!! I am going to try to replace the TOB this weekend, hopefully it hasn't damaged the pressure plate.
FIVEOH:
The driveshaft came from summit and it eliminated the vibration above 70 mph. The vibration doesn't feel like it's coming from the front of the engine, more so towards the rear. Could a bad pilot bearing be the cause????
I can't really put the old one back in b/c I took the front yoke off to plug the tranny during removal.

Does it vibrate while the car is in neutral or only when in gear?

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Joe! 1988 GT, 167,000 miles!!! 13.58@105mph Check out my listing! Click here! Or my website:www.joe4speed.com
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It doesn't matter, it does it whenever the engine gets past about 3500 rpm. I am pretty sure it's the balancer. I found the receipt and it has a 1 yr warranty. I just wouldn't think it would go bad so soon. Is it possible to install it 180 degrees off??? Surely I am not that dumb.
Can you get a "bad" balancer from a parts store??

I had an out of balance flywheel that did the exact same thing, but it was a horrible vibration. I replaced the pulleys, and the harmonic balancer before i checked that! Good luck!

You did get the correct weight balancer, yes? I don't know what year you're talking about, but your choices were a 20oz & a 50oz. They made the change in 1985 ('84 and older = 20oz. '85 and newer = 50oz).

Take care
~Chris

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Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

My fan clutch caused the same problem on my car.

Ditto for me on the fan clutch. A couple of the balls fell out of it and it caused a horrid vibration at a certain RPM regardless of gearing or speed.

Bob