Vibration?

[Eggy44]

Hey guys. Ive got a vibration in my Malibu when i go past about 45 mph and i cant seem to find out what is causing it.



I'm thinking that its either the ujoints or the driveshaft is out of balance.
Any other ideas besides those guys? Thanks!

[LSx_88_Ciera]

tire?

[Eggy44]

it does this weird thing where it will almost pulse. it will vibrate bad for a couple seconds then not too bad for a couple seconds and so on. it could be the tires flat-spotting from sitting too much over the winter.

Thanks for the help

[nicks67camaro]

Did it just happen? Did you change anything?

[Eggy44]

I drove it last year before i put it away and it ran without a hitch. i take it this year for the first time and its got that vibration. Its got the stock driveshaft in it with the stock ujoints from 1981 in it trying to hold up about 450 hp so that's probably not good for it either.

[Gitter Dun]

I'd say u-joints, driveshaft out of balance, or rear end.

[nicks67camaro]

I'd say u-joints, driveshaft out of balance, or rear end.

Agreed, These are where I would start. I had a SOB of a vibration last year after tearing every aspec of the driveline apart I found it to be the trans mount.
Good luck

[Eggy44]

Do you think maybe i got bad motor mounts or something like that? i have stock gm mounts and i have an energy trans mount. You think maybe I need to step up to poly motor mounts. I dont think thats it but its just one more thing

[nicks67camaro]

I havn't seen motor mounts cause a driveline vibration. My issue was the reverse. I had good motor mounts, solid body mounts, and an energy suspension trans mount. I needd to go to a cheap soft mount for the trans since it transered any vibration directly to the body of the car. Now with the cheap trans mount its smooth as can be. How old are the tires? Does the car sit for a long time? Did you lose any air in your tires?

[Gitter Dun]

Do you think maybe i got bad motor mounts or something like that? i have stock gm mounts and i have an energy trans mount. You think maybe I need to step up to poly motor mounts. I dont think thats it but its just one more thing

Step on the gas and the brake at the same time and have somebody look under hood, you'll see if you have bad motor mount, definitely not your vibration problem tho.

[Eggy44]

I did lose a little air over the winter in the tires which could mean that they are flat-spotted and making the vibration worse as i go faster. the front tires are about a year and a half old and the rear tires are about 2 months old