Well I get off of work today and decide to hit the interstate on the way home instead of driving through town. I'm about halfway home when all of a sudden I get a loud vibration all through the car. I thought I had a blowout, but it seems suspicious because there was no explosion sound that typically goes with a blowout, just instantanious vibration from having normal highway vibration. Well I call up a friend before I get out to look at the damage to have them come pick me up and get the tire replaced. Well after talking to them I get out to look and I check all tires and none are blown out, I kick them to double check and still nothing. Well then I thought maybe my driveshaft, I look underneath and it's still where it's supposed to be. I go up front and look underneath all the way back and no I am not dragging anything like the chin spoiler. So my friend comes and we both look the car over again and I have him follow me so I can limp the car home. I start out carefully and no vibration yet, as soon as it shifts to second the vibration starts and then it just stays and only gets worse with the higher in speed I go. I putt along at 30 and get home finally. On the way home it sounds like some metal is clanking around somewhere so I think maybe a u-joint went bad. Well I crawl underneath the rear and look at the u-joint at the rearend and it is fine. I try to move the drive shaft and it won't budge. So now I am stumped. The tranny shifts fine, actually better now than it ever has, and the engine sounds fine. What can it possibly be? I am at a complete and total loss as what could be wrong. Please throw some ideas at me and I will go check before I lose anymore sunlight. Thanks.

 

ok, time to narrow it down;

while idling in driveway ; motor related
while rolling down the road in neutral ; rear end or driveline related
only while in certain gears ; tranny

So, to me it sounds like rear suspension or driveline. Jack it up as high as you can, and start it and put it in gear. let it "roll" along at 10 MPH or so, and look at your car. See if anything is amiss. Peek under and see if anything is gone or trashed. Rev it up, and see if anything is flapping in the wind.

Then start tearing it apart.

 

I had a simalar problem a couple of months ago, turned out to be the trans mount. Just my

 

While it is idling, it sounds just fine. I haven't tested it in neutral while rolling down the street. It might be the tranny, but the was just rebuilt 4 months ago. I guess if it is the tranny that just means I'm s.o.l. for a while until I come up with the funds for a 6sp manuel conversion. Thanks.

 

Shouldn't a broken tranny mount be a dead give away? When I busted mine a couple years ago, the shifter was moving all over the place. Unless the 700r4s are better secured in the center console area than the T5s are, making it harder to see visually. But you should surely still be able to feel it when you hold the shifter.

 

If only the rubber has degraded then with an auto, I don't know about a manual; the shifter isn't gonna move but at speed your gonna feel like the cars coming apart.

 

yea, if the mount is broken on an auto it will lift up under load and through the driveline geomotry all out of wack causing some really bad vibration

 

First thing to do, is to get LOGICAL.

You can play the "maybe it's this, maybe it's that" game until your bank account is COMPLETELY empty and your dredit cards MAXED OUT, and not accomplish a thing.

The first question to answer is, is this vibe at wheel speed, or at drive line speed? It's VERY EASY to tell the difference, considering that the drive shaft side of things spins at somewhere around 3 times the rate that the wheels do.

Next, if it's a drive train problem, does it do it sitting still and revving the engine to cruise speed? (2500 RPM should do the trick...) If it does, then it's in front of the transmission. If not, it's between the trans and the pinion gear.

You can't tell anything at all about U-joints by looking at them or feeling them. That's one part where, if your logic doesn't otherwise eliminate them from suspicion, it's worthwehile to just swap them. $25 and a half hour or something, they're eliminated.

Etc. etc. etc. ..... use logic. Think, sniper rifle, as opposed to cluster bomb.

Obviously is it's a drive line problem, you can spend $10,000 on wheels and tires and whatever else, and have no effect whatsoever; and vice-versa.

 

Well, I've yet to have anytime to look at the car because as soon as I made my second post, the wife came home and had to tell her what happened and then of course came the hour long discussion about why I shouldn't have gotten the car. So I might get a chance tonight or tomorrow. Thanks for all of the input you guys have given to me.

 

I have a vibration in my car right now , but I know what it's from. the harmonic damper is bad on mine. im waiting for a new one from TCI.

as for the tranny mount I have had to replace mine 2 times and the passenger side motor mount. but that was my bad. I am running 295 50's out back with 400hp at the wheel.

but when the transmission mount breaks the torque arm would cause the tail of the tranny to smack the floor of the car when I put it in gear.

the motor mounts if bad can cause some vibration also. but its easy to see if one is bad. just look at the engine to see if it raises to much while someone revs the engine.

a warped brake rotor can cause it also, if they are in question get them turned.

do your wheels have wheel weights on them? for ballance. if one falls off, you maybe able to see a mark on the rim where the weight used to be.

tire could have a belt broke. jack up each wheel one at a time and with a glove on your hand feel along the tread all around the tire for a lump or any sunk in places. or rotate the tires and see if the vibration getts better of worse.

there are so many things can cause vibration just takes time and dont go out spending cash untile you find the cause of the vibration, or you will be in the doghouse for a while.lol

 

Well I went out yesterday to do a couple of checks on the Formula and this is so far what I have found. When I started the car, the engine sounded fine. I revved it up a bit and no vibration. Put it in gear and jerked slightly like it usually does. I drove it around the block and the vibration started to occur as soon as I got up to about 20 mph. I got the car up to 30 with vibration still going on and put the car in neutral. The vibration stayed and did not go away after being put into neutral, so I parked the car and looked around underneath if I could tell that the tranny was hanging any lower or looking different, but of course really could tell because the crossmember is holding it in place and the lack of actually being able to crawl underneath and look. So I plan on taking it to the shop and getting a better look underneath the car there. Thanks for all of your help and suggestions.

 

Transmission mount could definitely cause the problem. That's an esay check after getting the car off the ground. While it's up, check the rest of the driveline componets and make sure nothing is loose. However, this sounds more like a wheel weight got thrown off like darrells3rdgen said. Get your wheels balanced. It's not that expensive and you can talk to the tech to see if he can spin them before he pulls your old weights. That will give you a good idea how bad they were to start with.

 

Zig, thats exactly what I am going to do. Today me and a buddy went for a spin in the Formula and the shifter stayed good, checked the u-joints and they are good as well. I know I need new tires, except these still had some life in them, but apparently not anymore. We couldn't find anything wrong with the actually rubber on the tire, it's just a low amount of tread. More and More driving around we think the vibration is actually comming from the front of the car. Since I am not driving the car until it is fixed I can afford to let it sit for a while tell I have some cash for new tires, but I am going to go have the tires balanced and see if that solves the problem. I might also have a problem with the front suspension, so I will have that checked out also.

 

If you think something broke in the front suspension, you can sightly turn the wheel at a lower speed and see if the vibration stops or at least changes. If not, I still say wheels out of balance. The tires could have a broken belt, but a bald or nearly bald tire alone would not suddnely cause a vibration.

Hope you get it worked out with the other half. I go through that just about every time I spend money on my car. Try to help her understand it's not just a car, but a hobby. And that it could keep you off the streets and out of trouble!!

 

front ball joints?

try jacking up the front end, so the front tires are hanging (jack under k-member), and put a hand on the top of the tire, and one on the bottom, try and wiggle it, top out- bottom in, top in- bottom out sorta thing. That'll tell if your balljoints are shot.

 

check your drive shaft for balance wieghts to see if one of them or missing. if it is find another drive line,the vib. could tear up the rear pumkin or tail shaft on trans check it might be the problem

 

Thanks for the responses, looking into new tires soon and then getting the car to my shop (about 10 miles away from where I currently live) and then get under the car and test some more possibilities. Oh with the wife situation, she's all fine and dandy on buying books, but the second I want to buy a car part I get the 3rd degree. I tell you women, you can't live with them, and you can't kill them legally.