Driveshaft vibration?

[HoustonGT]

Hey guys. I got a quick question for you. I have a vibration i can feel under the car and the faser i go the worse it gets. Seems to be most noticeable around 70-75. I would describe as what you would feel through the steering wheel if you needed to balance and rotate the tires, but instead of feeling it through the steering wheel, i feel it through the seat and gas pedal. It feels like it is coming from the area between the firewall and back to the transmission.
Could this possibly be a bad u-joint or a driveshaft out of balance?

 

[StangGT96]

Another possibility would be where the driveshaft bolts up to the differential. I had a similar experience, bad vibration and noise; I figured out that when i bolted on my driveshaft i didnt torque it so the bolts came on done. Check that. Also if everything check out could be the u-joint.

 

[soctty7676]

All I can tell you is good luck! I have a '98 GT Convertible. I have replaced all 4 tires, had them balanced twice. Replaced 1 wheel because I thought it was bent. Then replaced the driveshaft with a new aluminum one.

Guess what! The F'n vibration is still there! I gave up and decided to just live with it. The only other option I had was to pay big $$$ and have it speed balanced. I'm not sure what exactly they do when they speed balance it, but they assured me they would find and fix the problem. Which they better for $500+.

 

[HoustonGT]

Interesting. Also, my clutch is starting to wear ou, so could it be that its just clutch chatter or is that not capable of causing such vibration?

 

[Mike97gt]

have you had the driveshaft out recently?

 

[mity2]

Check your U-joint. And also check to make sure thatU-joint is pressed in all the way. My Aluminumshaft shook, and turned out that I didn't press in U-joint enough so that it was off centered. And also make sure that bolts at the pinion is tightened.
Balance driveshaft is always good idea(cheap too).
But i would check common place first like tire, control Arm bushing, bad shocks aligment...

 

[HoustonGT]

have you had the driveshaft out recently?

No sir... Have you noticed that my car has been pissing me off lately? lol

You've replied ot just about every thread ive had...First the damn a/c clutch, then the TOB, now this vibration. Honestly, im gonna kick my car's ass pretty soon. THe only good thing right now is that my gas mileage went up alot after switching out the fuel filter.

But i appreciate all your help thus far. I'm gonna climb underneith the car and see if anything seems loose or if the driveshaft has excessive play in it.

 

[COramprat]

Two things I've experienced with vibration...

When my u-joint went bad it started as a vibe in 5th around 70-75. It then progressed to all gears at around 2000rpms. Was a real deep, moaning sort of sound. The needle bearings in one knuckle of the u-joint had disentigrated.

My other problem was recently after a rear-end collision. The tranny mount cracked and caused the vibration as soon as I started the car and would smooth out as I drove.

 

[HoustonGT]

Two things I've experienced with vibration...

When my u-joint went bad it started as a vibe in 5th around 70-75. It then progressed to all gears at around 2000rpms. Was a real deep, moaning sort of sound. The needle bearings in one knuckle of the u-joint had disentigrated.

My other problem was recently after a rear-end collision. The tranny mount cracked and caused the vibration as soon as I started the car and would smooth out as I drove.

Thanks for your input. How much and i looking at for a new U-joint and install?

 

[hognutz]

ujoints
driveshaft balance
wheel balance
worn bushings or mounts
wheel bearings
axles

there are many places that can cause vibration. I can only say start looking at them. drivetrain does not have much play so I would start looking for it as well as have balanced parts verified.

you can always put the rear on jack stands and run the car up to speed.

 

[HoustonGT]

ujoints
driveshaft balance
wheel balance
worn bushings or mounts
wheel bearings
axles

there are many places that can cause vibration. I can only say start looking at them. drivetrain does not have much play so I would start looking for it as well as have balanced parts verified.

you can always put the rear on jack stands and run the car up to speed.

Well, i got under the car and the driveshaft only moves ever so slightly and clunks, but the movement isn't excessive or anything. I can rule out the axle because its coming from the front and the the wheel balance problem because i don't feel a thing through the steering wheel, its steady as a rock.
Only thing i havent considered is possibly my tranny or motor mounts since the car also shakes kinda rough at idle.

 

[HoustonGT]

BTW, svtttech....

When i was under the car a few minutes ago i had the old man start it and listened for that noise i described ot you in the other thread. It was definitely coming from the transmission, more specifically the clutch and TOB, so its not up at the front by the a/c clutch and pulley Itll be taken care of by the King Cobra which comes in on the 13th

 

[mity2]

Thanks for your input. How much and i looking at for a new U-joint and install?

U can get new U joint for about 20bucks each. and if you have benchVice, u can replace it yourself. Its 10min job.

Just don't use C-cramp. Trust me on that