Car Shaky At 100 MPH

[Danman765432]

I was just wondering what would cause vibrations at this speed. When I hit 100mph i get some vibrations going throughout my car, the main thing is i still feel perfectly in control of the car. I did take out my strut tower brace a while back, but this seems to be a recent thing, because it hasnt done it before...Im just wondering if it could be the driveshaft or something


Also when normal driving around town I get this whining sound above 10 mph it sounds like it is coming from the middle to front end of my car. This only happens when the car was in motion...I was thinking it could be the gears at first and I just thought it was from the front but the sound tends to be quite sometimes and also get louder at times.

 

[click]

My car used to wobble at about 95 and above. But it is now even worse and wobbles as early as 75mph. And i feel it through my shifter. Almost to the point where i can't hold on to the shifter and it kicks out of 5th into neutral. So i don't know if you have vibration up through the shifter but I'm replacing my u-joints tomorrow, so i'll post here to let you know if it solved my problem.

 

[HISSIN50]

Do you have any guess as to whether it's an imbalance issue with a hard part, or if it stems from harmonics/resonance?

 

[Adam95GT]

U joints... Alignment... wheel balance.... tire preasure... could be alot of things...

 

[Bosko5.0]

worn bushings, i had a bad vibration 50< above due too bent axle shaft.replaced fixed it but now vibration 80< due to worn out parts/bushins.

 

[94Cobra69SS396]

I had a vibration that started at about 100 as well with my old T5. I've now installed a T56 and the vibration is gone. However, I do not know if it was in the trans or the driveshaft. Finding a vibration like this will be a process of elimination. Everything mentioned above could be causing it.

 

[Methodical]

How about trans mount?

 

[Methodical]

Transmission mount?

 

[Danman765432]

thanks guys i guess ill just have to start trying to narrow things down.

 

[donkey_punch]

if you did gears and still have stock drive shaft, my money is on you have to go to an aluminum drive shaft.

 

[Bosko5.0]

aluminum driveshaft

 

[stangman94]

that used to happen to me at 75mph found out one of my tires was 5psi lower and balance was off. Thats probably the problem for you i felt like i still had control too.

 

[Danman765432]

Yeah im going to check my tire pressure, because it got really cold up here and i havent checked it since the summer so im probably running a little low on the PSI and if not ill probably do the driveshaft since ive been wanting to do one anyway.

 

[1TallMF]

Yeah, I get a super high frequency vibration at 100mph (like a humming) too, and its worse when I let off the gas. The shifter becomes a blurr of shakiness. I'm hoping an aluminum DS will fix it. Seems to be a common problem with steeper gears and stock driveshafts on our cars.

 

[click]

Hey well i put in new u-joints today. And it feels like a totally different car. When i got the driveshaft out and inspected the front joint, the metal cap actually was broken. So it would rattle around and shake my car at 75+ mph. It used to do it at like 95+ but i guess over the year it got worse. The easy way to check it get under the car and grab the driveshaft and try turning it. If you have a clunk sound coming from one the joints, then inspect them closer. That's just my 2 cents that solved my shaking problem. I hope you figure it out.

-John

 

[HISSIN50]

When i got the driveshaft out and inspected the front joint, the metal cap actually was broken.

I'm quite glad to hear that you got it fixed. Was there any carnage from the slop?

 

[click]

haha i was quite surprised that the yoke wasn't destroyed and surprisingly the joint maintained it's shape and structure...
it was just hitting back and forth when i came to stops and 75+ mph.
And my ride sounds so much more quiet.

 

[donkey_punch]

you're luck it didn't snap and throw you into an ass over head cartwheel.