Ridiculous vibration

[Renob89gt]

So I have tried looking around and found a few different things but nothing quiet fitting for me.

1989 mustang GT 306 w/ svo heads and xcam explorer intake. Nothing overly crazy but I have a nasty vibration coming from the trans area/shifter as my rpms go up. You can begin to feel it around 2500 but really shows at 3k. This vibration comes whether I'm sitting in garage or driving down the street, with or without the clutch in. As I've worked on fixing the car up and done thing to it to help it be reliable and smooth I've kind of chased the vibration. I feel like I've covered all the basics that I read about in other posts Everything below I've done....
FRPP aluminum drove shaft w ujoints
New 3:73 gears
New clutch w/FRPP 50oz flywheel, new hearing with it.
New FRPP 50oz balancer
New Hurst shifter
Have electric fans
New wheels and tires balanced

Appreciate any input on ideas. Just wondering if it means rebuild/ new trans. Wife will really love hearing that.

 

[Deleted member 215073]

Motor mounts? Is the balancer the steel one with the removable weight or does it look like the factory one?

 

[General karthief]

Check the firing order, the non ho firing order will make the vibration you feel.
If the vibration is present standing still with the clutch depressed it will be engine related.

 

[Renob89gt]

Motor mounts? Is the balancer the steel one with the removable weight or does it look like the factory one?

Motormounts are new, and so are trans mounts. Forgot to mention that

 

[Renob89gt]

Motormounts are new, and so are trans mounts. Forgot to mention that

Balancer was the same as factory

 

[Renob89gt]

Check the firing order, the non ho firing order will make the vibration you feel.
If the vibration is present standing still with the clutch depressed it will be engine related.

I'll double check the firing order today. Would this not make the car run rough? Seems to run and start well.

 

[General karthief]

I'll double check the firing order today. Would this not make the car run rough? Seems to run and start well.

It will run fine just down on power and a nasty vibration

 

[Renob89gt]

It will run fine just down on power and a nasty vibration

Firing order is good to go. It certainly doesn't feel down on power. Runs good other than this dang vibration. Lol all new plugs, cap and wires as well.

 

[General karthief]

You are using the HO firing order right?

 

[Rdub6]

I had a fan clutch go bad on my first fox years ago. Caused a real bad vibration that took me a while to track down also!
One day I happened to spin the fan by hand and saw it wobble. Changed the fan clutch.... no more vibration.
Worth a look.

 

[Deleted member 215073]

He stated the fans are electric

 

[Rdub6]

I guess it’s not the fan clutch.

 

[Renob89gt]

You are using the HO firing order right?

Yes. Got the correct ho order

 

[General karthief]

It's only a guess but it's possible there is something amiss with the clutch/flywheel, hard to say without putting hands on it. Pilot bearing maybe, imput shaft in the trans, like I said hard to say.
If the pulleys are good, no balancer wobble, no engine miss that's the next logical area.

 

[deathb4dismount]

Was this vibration present before the xcam?

 

[Renob89gt]

Was this vibration present before the xcam?

Cam was done by previous owner.

 

[Renob89gt]

It's only a guess but it's possible there is something amiss with the clutch/flywheel, hard to say without putting hands on it. Pilot bearing maybe, imput shaft in the trans, like I said hard to say.
If the pulleys are good, no balancer wobble, no engine miss that's the next logical area.

By chance would rockers/lifters cause a vibration like that. I was under there today and it sounded to me like there may be some tapping going on. Not 100% sure as I'm not a great mechanic but could it be a cause?

 

[General karthief]

Run a compression test, a dead hole will make it vibrate.
Well, more of a shake.

 

[Exrace89GT]

Take the fan belt off and run it for a few minutes. That eliminates any of the engine driven accessories.

 

[LX1993]

If you're sure it's confined to shifter/trans, it sure sounds like a throw-out bearing. Preload should be 5-7#.