[97gt]

Ive got a 96 gt 5 speed. Whenever i hit around 50mph i get this horrible vibration in the car and it gets worse as i go faster? i thought maybe it could be the tranny mount so i replaced it, but it still vibrates.. anyone got any advice?

[v606er]

i was gonna say go 60 but since it gets worse at higher speeds...go 100

[v606er]

o but really maybe your alignment is off

[97gt]

well i dont wanna go any faster im afraid ill break something. when i did accelerate to 70+ the vibration gets really worse everything is vibrating my sideview mirrors, the rearview mirror, shifter, steering wheel, everything. could it possibly be my alignment?

[v606er]

Originally Posted by 97gt well i dont wanna go any faster im afraid ill break something. when i did accelerate to 70+ the vibration gets really worse everything is vibrating my sideview mirrors, the rearview mirror, shifter, steering wheel, everything. could it possibly be my alignment?

ya coulld be. that would mess up the wear of your tires and youd have a worse ride. or if you have really cheap tires they might not ride right. if you've given your suspension a pretty hard time, or if you've never replaced your shocks, it could be that your shocks need replacing

[97gt]

alright well thanks for all your help. ill probably end up takin it to brakes plus or something and have them look at it. Thanks!

[trvsg55]

this might sound stupid but i would check the driveshaft to make sure all the bolts were tight i only say this cause i had that problem and i couldnt't figure out where the shaking was coming from and it was the driveshaft 2 of the bolts came off and the other 2 were loose

[97gt]

you know trvsg55, you might be right... cause i just finished dropping in a new engine and tranny. maybe i didnt tighten them as much as i should have. I'll give that a shot! Thanks!

[NMR-2vGT]

Did you check the motor mounts and ball joints?

[ILUVSTANGS]

balancing of the tires "most of the time" is the reason for the vib. at your speed....
align. resolves other issues with your tires. caster\camber\toe...
also check your lug nuts..as in torque...i have seen lots of tire guys leave lugs loose and it will cause the tire to wabble and cause vib at any speed....
good luck.....

[NinetySixVert]

Originally Posted by ILUVSTANGS balancing of the tires "most of the time" is the reason for the vib. at your speed.... align. resolves other issues with your tires. castercambertoe... also check your lug nuts..as in torque...i have seen lots of tire guys leave lugs loose and it will cause the tire to wabble and cause vib at any speed.... good luck.....

+1 for wheel balance. Have the wheels balanced and have a shop look over the rest of your car, I'm sure if it isn't the wheels that they will find your problem. Vibrations could be caused a numerous things, and it's hard to say when none of us but you have actually been in the car and felt them.

[97S281]

mine vibrated like a bitch when my u-joints went bad. the needle bearings were GONE and the driveshaft vibrated like crazy under any load, but the faster you went, the worse it got. I'd say +1 on checking out the driveshaft.

[97gt]

I'll check everything tomorrow, finally a day off work. Ill be sure to check everything you guys listed. then ill take my car in for an alignment and see if they can find any problems. thanks for all the advice guys! i really appreciate it!

[snoel123]

Bad alignment will not cause a vibration, it can lead to tire wear which can cause a vibration. Run your hand along your front tires to feel for uneven wear such as cupping feathering or accelerated wear one one portion of the tire. If your vibration is only related to speed suspect wheel balance or hub runout. As someone else said if you can manipulate the vibrations intensity or frequency by changing load (ie. changing throttle position or putting the car in neutral/pressing the clutch to see if it goes away.) suspect driveline vibration. Also worn pinion bearings or a worn tailshaft bushing can cause vibration concerns. The best way to check is put the car in neutral, get it up on stands and grab the driveshaft with your hands push it up and down and side to side to check for play. If no play is noted move to your extension housing end of the driveshaft and repeat, try it again at the rear diff. watch closely to determine if the play is in the u-joints, diff flange or extension housing. Also while the car is on stands grab the front wheels and check for axial/lateral play which can cause bed speed related vibration. I have also seen vibration where someone has changed u-joints anf flipped the driveshaft end for end causing an imbalance. If it is speed related check all tires for wear, try to feel if it is coming from the front (the steering wheel, dash and front end will vibrate) the sunvisor put in a halfway down position helps here as it acts like a tuning fork and will vibrate fiercely if it is from the front end. If it is coming from the rear, (the seat floorpan and backseat will vibrate the most.) Be very careful diaging this as several times I have found loose wheels causing the vibration and came very close to loosing one. Also look for marks on you rims (if weight balances) where weights may have fallen off, note that if you have a dynamic or static wheel imbalance tire wear will be drastically accellerated and you may reduce tire life by 90%. Hope this info helps someone, Oh by the way I don't neccessarily post all this info saying you should do all this, you will know better where its coming from, I just want to cover all bases. There are several other things that can cause vibrations at highway speed including TCC (automatic) Chipped or distorted tooth on geartrain (manual). Basically anything that rotates vibrates so any deviation from balance can cause vibration. The best way to diagnose is to isolate the vibration (speed affected, load affected, front or back). And then diag accordingly. Keep in mind 90% of the vibrations I diagnose are wheel imbalance. I have advanced tools that help me though a sirometer and electronic vibration analyzer. I can move sensors throughout the vehicle and get an amplitude and frequency reading, with this I can pinpoint to exactly what wheel, or u-joint, or hub is causing this within 20 min. Beware though the standard time for N-V-H diagnosis is .7 hours. (noise-vibration-harshness). Without a sirometer, EVA and experience I've seen customers leave the stealership with 6 hours of labour for diagnosis. This is against the law as the book rate for N-V-H is .7. Hope this helps you.

[97gt]

wow... haha very nice! thanks for all the info!