[Dragon Rider]

I need help. I had a bunch of work doneto my ride and I now have a vibration everyone seems to have a different answer for.
The work included;
changed the rear gears to 3.55's
all new inards to go with gears and hubs (bearings, seals and the like) . all new brakes front and rear, new neroprean mounts, motor and trans, new heavy duty yoke and u-joints, removed cats to an off road 2.25" exhaust system (mufflers are Magnaflow) had a HP chip installed, throtle body rework, wires, plugs, All High performance (Malory) AND now I have this vibration that hits lightly at about 47-48 and again at 95-98. At the high end it's bad enough to pop open the glove box. I have reballanced the tires, swaped the tires, had the drive shaft checked (was told it's true and ballanced)and I still can't complete a run.

[stlwagon]

I would still suspect it might be something with the driveshaft. What year is the car?

[mustang4life04]

do you feel it in the steering wheel? if not its most likely coming from the rear, and ive had this poblem before and it was a driveshaft.

[rj8806]

What year is the car? Is it manual or automatic tranny?

Can you give us some more information on the vibration, like is it only under acceleration or deceleration? Is it still there if you throw it in nuetral? Is it present in any gear? Are you sure it is speed related and not rpm related?
You said it comes on at 47-48mph, does it matter what gear you're in? Try throwing it in nuetral when it starts and see if that changes anything. Try changing gears and see if it is still present.

You may try clocking the driveshaft 180* and see if that cures it. In other words, unbolt it, turn it 180* and bolt it back up and see if that makes a difference.

Where do you feel the bibration? Is it in the seat and floor boards or in the steering wheel?


Keep in mind that polyurethane mounts are alot stiffer than the stock rubber ones and will definitely transmit a minor vibration into the cab of the car and make it feel like a major one. If you put poly mounts under the motor and the transmission, it could be generating from the engine compartment and transmit down the car to the tranny area and then up into the cab of the car.



Richard
Tech Support
Tremec TKO, T45 & T56 Transmission Systems

[JeffM8810]

I just had the same problem with my 95 gt after i replaced clutch. Turned driveshaft 180 degrees and some vibration there but not nearly as bad as before.

[spdjnky_42]

Could be a 180 out driveshaft or loose driveshaft.

[96moonlightblue]

I'm pretty much having this same issue right now.My engine mounts were changed no vibartion. My clutch as been changed, there was no vibartion after this. I then had the rear gears changed to ford 4:10's now i have a vibartion in the floor board and it makes a thumb noise very quite but you can hear it really bad at about 65. get quiter then unbareably at high speeds. I changed the drive shaft to a ford racing drive shaft it got a little better but was still there. I changed the transmisson mount it got worse. I have now decied to have the guy who did the gears take a look hopefully he will find something and get it fixed. Love the feel of the new gears but this annoyed. I'll let everyone know what he finds when I hear from him.

[The Greek]

Check the drive line angles. Is the amount angle degrees the same in the front of the drive shaft as in the rear?

[BobEFFC]

+1 for drive line angles. Measure them with an angle finder.

[BobEFFC]

Before you employ anyone to install a gear set for you, ask them what that marking paste and pinion depth business is all about.

[Dragon Rider]

I want to first thank everyone for their responce. I do a lot of travel for work and don't always get bact to here or to the car and it's problims. I have however been able to spend time with it lately and the following was done.
The drive shaft was checked again for true and ballance, all good.
we popped the diff. open and well all I can say at this point is that a new set of gears are being installed. I decided to go with the 3.73's. I am hoping that this time the diff. can be set up correctly. AS a note the 3.55's had less than 3000 miles on them and they didn't look good, Nor did the fluid that we drained.
I will closely watch the vibration after it's done and if it remains, I will try clocking the drive shaft 180 to see if that helps. Other than this, I am hoping I have found the vibrtion.
Again, thank you all for your responces. They ALL help.
New work to the Dragonstang: 24# cobra injectors, Super E-Ram Electric Supercharger (about 2 or 3 PSI Boost at full throdle), 100 Shot of Nitrus, 10X26.5 BF Goodrich Drag Radials with 7X23front, Outlaw rims all around, Misimoto 2 core racing Radiator with high volicty fan, undersize pully set, and a buff job for the finish. Until now I haven't been able to get a full run (I am out of it about 200-300 feet before the line) but the times I have gotten were in the low 16's. If this new gear set works, I am hoping to get in the mid to slightly upper 13's. Only time will tell. if not, well ya gota keep trying!!!