Weird Vibration at high speeds

[whyask]

When Im driving the toy at speeds between 90-140 the whole shakes crazy! Now when i got my 4:10s installed right after that i noticed it, its never buged me until i was making a "bowl of rice" look like an idiot on the freeway... and i finally had the last straw with it. You think mayby a bad gear install?? any input at all would be great guys thanks

-Justin

 

[RedBullitt]

maybe something happened to the driveshaft balance at the shop?

ive had 410s for a long time and i never noticed anything like that. It sounds like something happened at the install. That would be a big coincidence if not

 

[Daggar]

I doubt that it's driveshaft balance. I have yet to see a driveshaft from a street car toss the balance. The track cars that I've seen do it also warped driveshafts, or broke yokes or did some kind of damage that was readily appearant.

My guesses would be that your gear inostall went poorly (as you suggested) or that you have one or more bad universal joints. EVEN if the U-joints are brand new, they can be bad (been there).

It's not to say that you couldn't have something going on that is forward of the DS but those things that I mentioned above are the most common.

You might also want to consider having the wheel balance checked. It doesn't have to be off by much at all to give a nasty vibe at 140 MPH.

 

[SVT32VDOHC]

Well I would say 140MPH any car will shake. My 96 Cobra growns above 100MPH. It isn't while I am on the gas, it is when I let off, you hear a growning....but no vibrations.

 

[DerekStangGT]

try balancing all four tires. your rears may be off balance. also, when they installed your gears, they may have turned your driveshaft when re-installing it. its balanced at a certain spot, but when you twist the driveshaft and install it differently in the yoke, it may vibrate.

 

[whyask]

and I think thats what it is, it feels like the driveshaft is unbalanced !

 

[trinity_gt]

It's the driveshaft.

First, stop driving the thing at 140MPH on the highway. Street racing is idiotic.

Second, if you continue to do this, you risk pounding the bushing out of the rear of the transmission or cracking the housing.

Get an aluminum piece, like FRPPs driveshaft. Should take care of the vibrations when you take it to the track...

 

[whyask]

You know whats funny, thats what just cracked not more than a month ago on the car. And even I got it all fix (brand new tranny) it still does it.....so drive shaft you say... hmmm, pretty easy install ..(basic mechanic skills..?)