Drivetrain Vibration...Any Ideas on what it is?

[fubu795]

Hey guys....quick question. I do know alot about stangs but trainys have never been my strong point, and I have a small problem. I have a 94 GT with a 347 stroker pretty well built. Recently I've been getting a violent vibration coming from the trainy above 2k rpms. I thought I might of broke somin in the rear but it vibrates at a dead stop revving it so that should eliminate the rearend problem.

Now I think its a trainy mount. I havent gotten a chance to tear it apart, been very busy but just wanted some opinions. The vibration gets so bad, you cant even take it above 3500k. Am I right about the trainy mount or could it be something else?

Any suggestions greatly appreciated!

Dan....

 

[SVTCobra306]

Does it have a tremec transmission? They're known for vibrations in SN95 cars because they are very tricky to get the drivetrain lined back up right...

Could also be a harmonic balancer, it will shake the whole car sometimes.

 

[fubu795]

Does it have a tremec transmission? They're known for vibrations in SN95 cars because they are very tricky to get the drivetrain lined back up right...

Could also be a harmonic balancer, it will shake the whole car sometimes.

Its a T5 with upgraded syncros and internals. Its been fine for a long time, over 5k miles now. The vibration definitly comes from the trainy, you can barely hold the shifter its that bad above 3500k. If you rev the car at a dead stop it still vibrates violently.

 

[whitecobra98]

The mount sounds like a good start.

 

[doubletrouble]

Tranny mount/ motor mounts, and Driveshafts account for a lot of the vibration in these cars. They go out between 75-100K miles in these cars, typically. Tranny mount being the cheapest of the 3, I would start with that.

 

[fubu795]

Tranny mount/ motor mounts, and Driveshafts account for a lot of the vibration in these cars. They go out between 75-100K miles in these cars, typically. Tranny mount being the cheapest of the 3, I would start with that.

OK I picked up a new trainy mount this morning, will try and put it on tonight. I know the driveshaft is an aluminum that has less then 10k on it. Also I had new motor mounts put in with the stroker. I guess its possible they could still fail. Lets pray its the trainy mount

 

[doubletrouble]

OK I picked up a new trainy mount this morning, will try and put it on tonight. I know the driveshaft is an aluminum that has less then 10k on it. Also I had new motor mounts put in with the stroker. I guess its possible they could still fail. Lets pray its the trainy mount

I bet that's it, since the other stuff is new. Good luck!

 

[svtguy22]

Let us know please how it turns out, my car shakes liek crazy at 110 plus

 

[fubu795]

Let us know please how it turns out, my car shakes liek crazy at 110 plus

lol, my problem is bascally from idle all the way up. Your problem could be a number of things at those speeds. Cheap tires, bent/curbed wheels, trainy mount, motor mounts, rearend, driveshaft. At those speeds there are a ton of things that could factor in.

 

[93LITE]

:shrug: I'm having a very similar problem with my 94 GT (306). On mine, at lower RPM's it feels like a miss, but as you raise the RPM's it gets worse and at 4000 rpm it will shake the whole car. We have replaced the clutch, dampner, and done a complete tune-up. Mounts all seem fine on mine, u-joints are good as-well. Guys are telling me now that they are guessing a bad crank? I guess I'm going to have to tear it down. :whine: Please, tell us if you find your problem!!! :cuss:

 

[fubu795]

:shrug: I'm having a very similar problem with my 94 GT (306). On mine, at lower RPM's it feels like a miss, but as you raise the RPM's it gets worse and at 4000 rpm it will shake the whole car. We have replaced the clutch, dampner, and done a complete tune-up. Mounts all seem fine on mine, u-joints are good as-well. Guys are telling me now that they are guessing a bad crank? I guess I'm going to have to tear it down. :whine: Please, tell us if you find your problem!!! :cuss:

God I hope it aint a bad crank. If it is, I'll do a 331 with a huge turbo, no more messing around.

 

[fubu795]

Found out my problem. The input shaft went BOOM. Not completely broken but cracked and wobbling all over the place. Guess then hard launches and torque didnt help Time for a tremic....

 

[SVTCobra306]

TKO600 time...

 

[fubu795]

Update:

Wasn't input shaft. I guess you call it the throwout bearing retaining clip was split in 2 pieces. Driving to summit in the AM to grab a new one....

 

[thenoz]

Let us know please how it turns out, my car shakes liek crazy at 110 plus

haha mine gets a little iffy around 130. stock suspension in a 15 year old ford... epper: