driveline vibration

[bigsexxy422]

so i have a vibration in the car when going around 65 mph. i just recently did a rear gear swap from 2.73 to 3.55. i figured it was the driveshaft out of balance since i only had a small vibration at around 100 with the old gears and its around 65 with the new ones. what do you guys think?
and anyone wanna sell me a alumineum driveshaft??

 

[95at5.0]

mine did the same thing had it balanced twice and installed new u joints and the problem was the slip yoke that slides into the trany. I still haven't figured out why though

 

[jka]

Could be your u-joints ...but check out your harmonic balancer too. I had the same problem just months ago and put in new u-joints and still had the vibration and then i checked the balancer... and it had rubber coming out of it. So i replaced it and know i have no more vibration...so after you check the u-joints check your balancer too.

 

[sleekkat232]

for $65, id change the balancer... i just went through this in my 94 GT w/ 3.73's... changed the u-joints, the pilot & throw-out bearings, etc... no change... put on a new balancer, and the friggin thing runs so smooth it, you cant even tell its running (aside from the full BBK exhaust)

its totally worth a shot, and assuming your car is of 79-95 nostalgia, it wont hurt a bit to spend the hour to swap it out anyway.

good luck

 

[LX302]

so i have a vibration in the car when going around 65 mph. i just recently did a rear gear swap from 2.73 to 3.55. i figured it was the driveshaft out of balance since i only had a small vibration at around 100 with the old gears and its around 65 with the new ones. what do you guys think?
and anyone wanna sell me a alumineum driveshaft??

I did the same thing years ago. 2.73's to 3:55's. Vibration at 55mph on up.
Replaced the U-Joints, redid the transmission, (other Issues), same vibration.
Put on the Alum. driveshaft, smooth as glass.

Others have tried balancing their driveshafts to only help a little. Do some more searching. Has to do mainly with the driveshaft spinning faster and then noticing the vibration that was always there, a little more.

 

[bigsexxy422]

thanks for the help guys, yea my car is a 89gt, and i did just have the motor rebuilt with a new balancer. but the shop who did it kind of screwed me, the just threw anything on it they had around the shop. i found chevy roller rockers on it (1.5s), and chevy pushrod guides. so the fact that the balancer is off is probly a good place to start. does anyone have any recomendations on a good balancer? for cheap? also i dont know is anyone is interested but i have a MAF sensor and computer off the car for sale. the ecm is a AL9 , and the maf sensor is for that computer. it came off the car. 89gt 5.0 5 speed.

 

[2000xp8]

First off, i was reluctant to respond to this post since the name bigsexxy makes me feel like i'm replying to a sleezy craigslist list ad, something i don't do anymore.
Come on man, have a mod change it. (unless you are some kinda of fat chick that thinks they're sexy)

Second, engine vibration and driveline vibration are two completely different things, one cannot be mistaken for the other.

If it's the balancer the problem is rpm based and will vibrate when the car is in neutral and not moving, same goes for the flywheel.

If it's the driveshaft back it will only do it with the car in motion.
Since you are suggesting the vibration is speed sensitive, the problem is somewhere in the driveshaft and back.
Now say the problem is really at 3000rpm in 5th gear, what happens if you drive 3000 rpm in 4th gear, does the car vibrate? If not, it's not your balancer.

If for some reason your balancer is bad, use ford racing or ATI only, the rest are crap.

If it's the U joints, just buy a ford racing aluminum driveshaft, the stocker is not worth new U joints or balancing.

 

[bigsexxy422]

well tahnks for the help, i kind of figured it was the driveshaft because if i push the clutch in the vibration is still there. so i guess i am going for the driveshaft.

as for the name, i am sorry to offend, i will see what i can do about it, didnt know people were so sensitive.