My 94 GT is having a drivetrain vibration problem. You don't notice it much until you get to about 70 mph. If you push in the clutch the vibration goes away, which makes me think it's either the tranny, drive shaft, or rear end. I haven't taken anything apart yet, but I was going to start with the u-joints on the drive shaft. The u-joints don't move around like they are going bad, but I figured that's the best place to start. I installed 3.73 gears with new bearings about 2 years ago, so I doubt the rear axle is to blame. Any other ideas? :BangHead:
vibration problem
- Thread starter BALZY_GT
- Start date
CC'S95GT
Post Whore
tranny input shaft bearing?
Win
Legend
Could be a Pilot Bearing. Or it could be your clutch disc or pressure plate got knocked out of balance.
ademily87
Well-Known Member
happened to me in the thunderbird. Started about 55mph and would go away when you pushed the clutch in. Got it on a lift and seen 2 bolts were missing out of the back of the drive shaft and the other two were loose. It was sitting sideways pretty much. It was rough lol
GDTrumbo
Well-Known Member
Be sure to at least check the harmonic balancer as well!!
GT
GT
MustangChris
Mythic Level
if it stops when you push the clutch in, you can count out the driveshaft, the clutch, the rear end as problems... all these continue to spin when the clutch is disengaged, and therefore the vibrations would continue whether or not the clutch is engaged or not.
i would look into motor mounts, harmonic balancer, and balancing your tires first.
Your drivetrain maybe transfering vibrations to your motor and your mounts are no longer absorbing them.
Your harmonic balancer might be giving out, although i doubt this is a the problem, its a 1 bolt inspection and an easy one to rule out right off the bat.
I honestly feel it may be your tires. When you get to 70, your off-balance tires may be sending vibrations to you, when you push in the clutch, the car slows down, and the vibrations arent strong enough or arent happening often enough anymore to transfer the feeling all the way to you. This is a $20.00 fix that should be done anyways as part of basic maintance, so you might as well do it now to rule that out as well
i would look into motor mounts, harmonic balancer, and balancing your tires first.
Your drivetrain maybe transfering vibrations to your motor and your mounts are no longer absorbing them.
Your harmonic balancer might be giving out, although i doubt this is a the problem, its a 1 bolt inspection and an easy one to rule out right off the bat.
I honestly feel it may be your tires. When you get to 70, your off-balance tires may be sending vibrations to you, when you push in the clutch, the car slows down, and the vibrations arent strong enough or arent happening often enough anymore to transfer the feeling all the way to you. This is a $20.00 fix that should be done anyways as part of basic maintance, so you might as well do it now to rule that out as well
MustangChris
Mythic Level
also, since you have a 94 with a t5, take a look at your transmission mount.
I suggest (if its bad) replacing your motor mounts and transmission mounts at the same time. I also suggest using mounts that are made of simular compounds (if you get solid motor mounts, get solid transmission mount; if you get poly motor mounts, get poly tranny mount; etc. etc. etc.)
here is a link to a Name Brand, Poly, Tranny mount
http://www.jegs.com/i/Lakewood/620/24351/10002/-1
I suggest (if its bad) replacing your motor mounts and transmission mounts at the same time. I also suggest using mounts that are made of simular compounds (if you get solid motor mounts, get solid transmission mount; if you get poly motor mounts, get poly tranny mount; etc. etc. etc.)
here is a link to a Name Brand, Poly, Tranny mount
http://www.jegs.com/i/Lakewood/620/24351/10002/-1
MustangChris
Mythic Level
motor mounts:
http://www.jegs.com/i/Prothane/311/6-501/10002/-1
tranny mount:
http://www.jegs.com/i/Prothane/311/6-1604/10002/-1
Clearly these are a little pricey, so if you dont think these are the problems, i dont suggest buying them. lol.
http://www.jegs.com/i/Prothane/311/6-501/10002/-1
tranny mount:
http://www.jegs.com/i/Prothane/311/6-1604/10002/-1
Clearly these are a little pricey, so if you dont think these are the problems, i dont suggest buying them. lol.
2slo95fiveoh
Well-Known Member
If his tires were out of balance he would feel it with the clutch in or out, at the same speed.
I would check:
Harmonic Balancer
Driveshaft bolts
Transmission Mount
I would check:
Harmonic Balancer
Driveshaft bolts
Transmission Mount
I just put on a list of new parts recently with my supercharger project.
Urethane motor and tranny mounts, I also just put on new wheels and tires, and It seems to be a little less of a problem, but it's still noticeable. Last year I replaced the balancer with a new frpp balancer, the flywheel was resurfaced and a new clutch was put in. I'm thinking that it must be the drive shaft, so that's where i'm going to start. The u-joints don't seem bad, but who knows, maybe one is getting dry. The slip yoke of the driveshaft wiggles a little in the tail shaft housing of the tranny, but I was told that a little movement is normal. I'll just replace the u-joints and get the shaft balanced and pick up from there next spring. Or maybe this is more noticeable because of the urethane motor and tranny mounts. Either way, thanks for all the ideas guys.
Urethane motor and tranny mounts, I also just put on new wheels and tires, and It seems to be a little less of a problem, but it's still noticeable. Last year I replaced the balancer with a new frpp balancer, the flywheel was resurfaced and a new clutch was put in. I'm thinking that it must be the drive shaft, so that's where i'm going to start. The u-joints don't seem bad, but who knows, maybe one is getting dry. The slip yoke of the driveshaft wiggles a little in the tail shaft housing of the tranny, but I was told that a little movement is normal. I'll just replace the u-joints and get the shaft balanced and pick up from there next spring. Or maybe this is more noticeable because of the urethane motor and tranny mounts. Either way, thanks for all the ideas guys.
2slo95fiveoh
Well-Known Member
You are right about the movement in between the tailshaft housing and slip yoke... there should be a slight amount of movement there,
but nothing excessive, obviously. And the Urethane mounts will cause a little more excessive road vibrations.. Stock replacement
trans. mounts aren't that expensive from Parts stores.. You could buy one and swap it in and see if it helps your problem.. If not, then just throw
it back in the box and return it..
but nothing excessive, obviously. And the Urethane mounts will cause a little more excessive road vibrations.. Stock replacement
trans. mounts aren't that expensive from Parts stores.. You could buy one and swap it in and see if it helps your problem.. If not, then just throw
it back in the box and return it..
95DarkGreenGTS
Active Member
i had something similar when I first got my stang. About 70mph and let off gas it would viberate bad. It ended up being that 2 of the 4 bolts on driveshaft to rear end where missing and the other 2 where about out. Might want to take a visual look at that
