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bad vibration while accelerating help please!!!

01RedfireGT

01RedfireGT

New member
:confused: My 01 GP GT has a bad vibration while accelerating and espescially while turning right or past 70mph while accelerating. I'm 90% sure my driver side wheel bearing needs replaced becasue I heard a hum while turning right going fast and now a squeak while going slow from that side. I have a bent wheel onthe driver side rear but the tire is wearing fine. I was thinking my engine mount, but which one would cause a vibration while turning right? Or do you all think its just my junk wheel bearing? But if it was the bearing why only vibrate badly under acceleration and not when I let off, just a hum then from the bearing. Thanks in advance guys!---Joshua
 


check th enigine mounts. that can cause alot of vibrating. i know my old gtp used to have a really bad vibrating at around 1600 rpm's. im pretty sure it was the mounts
 
Your wheel bearing will not causing vibrating. The way you tell your wheel bearings are going out is when you turn your wheel all the way over and give the car gas from a still position, you will hear them make a popping noise indicating a problem with them.

The vibration I had in mine was from the Driver side half shaft literally wobbling when I get to 40+mph. And it would continue until I reached a good cruising speed. The best way to tell if your half shaft is wobbling is to put it on a lift and have a tech sit in the seat and give it gas. You will either see the shaft stay true or it will wobble. That is exactly how I discovered my issue. Once I replaced it, problem was gone.

Now if your car is lowered, and you have not done the spacer trick to equal out the half shafts, you will get vibration as well. Not quite severe as you mentioned, but you will feel it the steering wheel after you hit 60mph+

Examining your engine mounts and tranny mounts is not a bad idea as well. Check for wear, cracks, or even leaking hydrolic fluid from them if they are the stock ones.

I hope that helps steers you in the right direction.
 
GeddyLee said:
Your wheel bearing will not causing vibrating. The way you tell your wheel bearings are going out is when you turn your wheel all the way over and give the car gas from a still position, you will hear them make a popping noise indicating a problem with them.

The vibration I had in mine was from the Driver side half shaft literally wobbling when I get to 40+mph. And it would continue until I reached a good cruising speed. The best way to tell if your half shaft is wobbling is to put it on a lift and have a tech sit in the seat and give it gas. You will either see the shaft stay true or it will wobble. That is exactly how I discovered my issue. Once I replaced it, problem was gone.

Now if your car is lowered, and you have not done the spacer trick to equal out the half shafts, you will get vibration as well. Not quite severe as you mentioned, but you will feel it the steering wheel after you hit 60mph+

Examining your engine mounts and tranny mounts is not a bad idea as well. Check for wear, cracks, or even leaking hydrolic fluid from them if they are the stock ones.

I hope that helps steers you in the right direction.
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No wobble in the steering wheel it stays true. Car is not lowered. I bet its my passenger engine mount thats causing it. The passenger engine mount is covered in oil and the cup also but nowhere else in the area. Question, I know bearings make noise when you turn opposite of the bearing thats going bad meaning turn right left bearing makes noise etc.... are engine mounts the opposite? Bad passenger mount = vibration while turning right.

Also, is there a difference in vibration between a tranny mount and engine mount going bad?

Thanks again guys!
 
GeddyLee said:
Now if your car is lowered, and you have not done the spacer trick to equal out the half shafts, you will get vibration as well. Not quite severe as you mentioned, but you will feel it the steering wheel after you hit 60mph+
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Geddy I just recently lowered my car and it vibrates when i accel but when i let off its fine but i was wondering what the "spacer trick" was.
 
you put spacers underneath the motor mounts so that it raises the engine and transmission back up so that the axle geometry is correct. that is the reason why it shakes when you lower the car. your other choice is to shorten the front dogbones about 3/4".

the spacers are the "right" way to fix it, but the dogbones work. ive got shortened dogbones on mine and it took away the majority of it to where i dont mind driving the car. before i shortened them it shook horribly.
 


yea i got shorter dogbones i mean its not bad like ya said were ya cant drive it but i yea i was just wondering thanks bro!
 
b00stinGTX said:
Geddy I just recently lowered my car and it vibrates when i accel but when i let off its fine but i was wondering what the "spacer trick" was.
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Well if you have not done the spacer trick, then yes your car is going to exihibit some vibration. I am running poly mounts for my motor mounts and the dogbones, those alone stopped most of my vibration. I am thinking I am going to have to break down and purchase a set of the spacer to truly put the engine/axel alignment right.

I am not a huge fan of the shortened Dogbones. Why? Well if you are running headers, not sure if the Plog would be susceptable to this as well, but when you use the shortened dogbones you pull your heads into the radiator fans. This is usually considered a BAD thing ;)

Some folks who cant or dont wish to pay for polymounts will do the stock bushing flip to help alleviate some of the vibration by keeping a "frimer grip" on the engine thus illiminating "some" of the vibration caused when lowering your car.

Just another thought for ya.
 
my headers rest on the heat shield for my radiator fans and they are going strong for quite a while already.
 
Bio248 said:
my headers rest on the heat shield for my radiator fans and they are going strong for quite a while already.
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I know Bio, I am just not a big fan of that. I am glad its worked for you no doubt, I would just perfer to avoid those potential issues down the road. Also it doesnt give you a great deal of wiggle room if you are trying to get into front area to work on anything.

We had a guy in local GP who we helped install his TOGs Extreme headers and he had the same problem, but his Dogbones on his 04 Comp G were stock and he was nailing the fan with them. If he had shortened Dogbones, it wouldn't have worked at all for him.

It was just a general observation :)
 
i think i would gain a little room if i were to switch to the 99+ fans as they are more slim line. mine are HUGE! :p
 


A friend of mine had a pretty bad vibration on his wife's GTP only under acceleration as you described. I drove it myself and noticed it right away. When you let off the gas, it went away. The problem turned out to be a bad CV joint. New axle assembly cured it immediately.

Ironically, it was a redfire metallic also. LOL! Doubt that had anything to do with it though. :p
 
Still havent gotten around to fixing it, but on another note, how do you guys go about changing the rear plugs on your 3.8's?
 
01RedfireGT said:
Still havent gotten around to fixing it, but on another note, how do you guys go about changing the rear plugs on your 3.8's?
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unhook the dogbones in the front. rock the car until the motor leans towards the front of the car and quickly engage the e-brake. you should be able to reach the rear plugs easier now. otherwise they arent that bad just normally.
 


when i go over a bump the car will vibrate even when i do a sweeping turn to the right but if i let off the gas it will go away, dont matter going straight or turning right it will vibrate and as soon as i let off gas it will stop how do i tell what axle it is the passanger side has been out befor put new boot on it bc the old one broke and the axle seperated
 
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