Need help with vibe problem

92greenlx

Founding Member
Mar 27, 2002
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I have been having a vibe problem for about 6 months now. When I get on my car it vibrates like crazy from 3000rpm and up. I cant see out of my rear view mirror becuase it shakes it up when I romp on the gas! I have an aluminum driveshaft thats been on about a year and has about 7000 miles on it. When I 1st put it on my car was smooth. Now I am wondering if that is causing any of this? I even changed out my old stock mounts to new solid ones. And guess what, it didnt make the vibe problem worse or better. The only way I can tell if I have solids is when I am sitting at idle. None of the weights have fallen off of my wheels. When I am crusing down the highway and put the car in nuetral(5spd) it feels smooth. Then once I am in gear and try to go over 75mph it starts to get vibration and more of it the closer it get to 3000rpm. Is there any way that my rear end itself could be causing any of this? My tranny? That too is about a year old with about 7000 miles on it. I need help on what I can change out to help this problem or eliminate probable causes. Like u joints and so on. Any ideas or suggestions?
 
ok, so the vibes go away at any speed while in neutral. and it happens at ~3K rpm in any gear, pretty much, if i read you right.
if so, i would really take a good look at the balancer.

good luck.
 
See thats what I was thinking too. I am wondering if the rear end could possibly be causing this as well? IS it possible for my rear to cause vibes? But if so then it would still vibe when I put the car in nuetral and coast down the highway right? How much does a new harmonic balancer cost? And where can I get one from besides a part store?

Thank you!
 
92greenlx said:
See thats what I was thinking too. I am wondering if the rear end could possibly be causing this as well? IS it possible for my rear to cause vibes? But if so then it would still vibe when I put the car in nuetral and coast down the highway right? How much does a new harmonic balancer cost? And where can I get one from besides a part store?

Thank you!
i would look at the balancer - if it is that bad, you might see it wobble or with cracked elastomer pieces. the DS and rear still spin the same whether you are in neutral or in gear - hence my thinking (and concurrence with your thinking).

there are some nice SFI and non SFI balancers out there. just your choice. you can do better than a generic parts store variety (some parts stores do carry some good brands though).

good luck.
 
were it me, i would probably go with a Pioneer if one wants a non -SFI unit. you can ask 10 people what flavor of balancer they like, and you will get 10 different answers.

i might do an online search for a vendor. i believe Strokermotors.com (not sure if that is the exact name) has some decent deals.

LRS (www.50resto.com) has a Professional Products street unit that i would have gotten had they had it in stock.

my two cents for now. good luck.
 
I went to a friend who owns his own shop and talked to him about it. He looked at my car and drove it. He was telling me that if it was the harmonic balancer I owuldnt be able to set the timing right. I dont have that issue. He drove my car and said that it felt internal. He was telling me that he has rebuilt a few 302's where a weight from the crank had come off and was causing vibes. So now its seems that basically its not going to go away until I rebuild my bottom end. Time to start saving up some money! I might as well get a set of heads and a cam then a stroker kit.
 
92greenlx said:
He was telling me that if it was the harmonic balancer I owuldnt be able to set the timing right.
as a blanket statement, that sounds alright. however, i would check the balancer anyways. if it has a cracked elastomer or wobbles, you would not want to reuse it in the future anyhow. what your friend is saying (i believe) is that you would not be able to time the car due to the timing marks being off if the outer ring slid (the elastomer went south). however, the outer ring can slide laterally (so when lookin at it in profile, it wobbles or oscillates). this would allow the timing marks to stay in their relative position while possibly creating some vibes.

do be warned that driving with the motor out of balance (no matter the cause) can severely diminish the life of the bottom end.

my two cents. good luck.
 
Well I guess as a precaution I can go ahead and change out the harmonic balancer. Then just go from there. If I still have a vibe problem then I have no choice but to assume that it is internal.