whats making my car vibrate?!!!!

[billbraskey]

hey all i no there has been a million threads on this... i actually chimed in on a recent one wich i now cannot find... but i havea vibration and dont no what is causing it... starts at about 50-60.. wich makes me not able to drive on e way .. or atleast i dont feel as if i should i cant feel it on the shifter pretty bad( wich is comon for aftermerket shifter? pro 5.0)... ok so.... driving 50- 60 it starts and get worse as i go faster... engine doesnt not vibrate in nuatral if i was sitting still revving it... i can run 1 all the way out hard no problem . .. and most of second...
soo wen im going 55 or so ( a guess speedo is off have373's) and its vibrating.. i push in the clutch it doesnt go away at all.. still does the same at 1000 rpm withe clutch is ... i was actually going faster the other day messing with it maybe 60 65 it was vibrating pretty bad... and i pushe the clutch in and it felt like it was getting worse.... any hhelp much appriciated...is it the wheels?? i thought my tires in the rear were never balanced so i got that done .. no help....hmmmcar sat for about 1 1/2 + without driving or being started... cold it have made a flat spot or anything in the tires???.. ok so id say about 1000 miles on fresh rebuild.. i beleive it has been vibrating since it has been rebuilt.....
85 gt..... stock rebuilt shortblock gt 40 irons e cam rpm intake full length headers 5 speed car with pro 5.0 ..373 gears... 10.5 inch clutch ) dont rember wich clutch im running its been a while... any help much appricaiated! p.s i have the stock t-5 with 150 thousand miles or so on it... no problems with vibration before i tore car apart and started restoring....
haave computer trouble sometimes i cant check on here for a day or 2 so bare with me!=)

 

[Gearbanger 101]

Didn't read it all the way through since your sentence structure is so horrible, but is sounds like you've got a bad U-Joint

 

[88mouse]

+1 for the u joints.

 

[Aliate X]

get a aluminum d/s, i had the same vibration problems, fixed it right up

 

[4G-KDMP]

check you u joints for excessive flex!

 

[billbraskey]

ok thanks how do i check for excessive flex?? hm whats a cheap way to fix it.. dont no if i have 250 bucks t shell out for aluminum drive shaft..

 

[4G-KDMP]

raise the rearend up off the ground and rotate the ds by hand and if you see any movement or wobble at all it's a good sign the your u joints or shot.

when going from forward to reverse and you hear a clunk sound is another way to check.

 

[billbraskey]

raise the rearend up off the ground and rotate the ds by hand and if you see any movement or wobble at all it's a good sign the your u joints or shot.

when going from forward to reverse and you hear a clunk sound is another way to check.

ok thanks alot... im gonna do that this weekend... hmm but if it is the u joint wouldnt it go away wen i push the clutch it or take it outta gear at those speeds.. cause it does not go away..

 

[nicks95stang]

Check the bolts that at the rearend that connect the driveshaft yoke to the pinion. It is very common on a fox body for these to vibrate loose. It happened to me twice. If they are loose, replace them with new ones. They are cheap and you can get them at your Ford dealer.

 

[HISSIN50]

Does the vibration change if you let off the gas while you're in the vibe-zone? Does it ever abate if you keep going faster, or once you reach 50-60 mph is it constant?

Good luck.

 

[Jzava50]

mine does this too!!! not so bad that it cant be driven tho... I was told it was the drive shaft to. Are there any thing else that i should replace while im in there ...what do you recomend as a manufacture?

 

[Threeo2]

I had a similar problem....vibrations at highway speeds. Everyone said it was the driveshaft.
Lucky me it ended up being a missing wheel weight, go figure. so for 2 bucks my vibration was totally gone.

 

[slappy9090]

I think we are overlooking the obvious, if a car sits for 1.5 years it could have asily developed a slight "flat spot on the wheels that might only be apparent at those speeds. Or it could be the balance, or it could be the beginnings of a seperated steel belt. I have seen brand new tires get put on a car and 2 days later the person returns and has that problem only at highway speeds so it could be a very easy thing. A wheel weight could have fallen off. Just some input from a used to be tire-tech!