When the Sport gets to about 75mph,there's a vibration then,after about 80,it seems to mostly go away,but,if I let off the gas at those speeds,there's more of a vibration.Any ideas? Axle bearings maybe?
Didn't you just get new wheels? Is it possible a weight fell off?
I'd vote wheel balancing or u-joint.
I vote U-joint, if it was there last week with the old wheels
I just swapped the u-joints,and the vibration was a little worse consistently after 75 before the u-joints.Even with the other wheels.
Thats the rumble of the V8. You'll get used to it after a while.
where does if feel like it's coming from?
front or back?
Back.I had the driveshaft balanced a while back,now it has new tires and wheels (that feel very smooth on the highway),and new u-joints.
I guess were heading towards the rear end now
bolts tight on the driveshaft?
Tight as they can be.
have you tried unbolting the d-shaft and rotating it and rebolting it?
Mabe it's out of balance with the rear end there
I'll try that and let you know what happens.
Is the drive shaft out of round/bent?
I just had it balanced.
There was no run out on the shaft?
stick a large hose clamp on the driveshaft and see if you can counter the vibrating by changing the position in 45 to 90 degree incremints. If it only gets worse, and doesn't get better, then it probably isn't in the drive shaft. I have had alot of bad luck with wheels and tires being balanced correctly, as well as the front suspension having alot of slack in it.
My Mustang did this and one of the axles were bent. 100% stock rear and drivetrain in the car with about 65,000 miles on it.
exactly.
or, your out of phase like Dr D said.
being out of phase on a two piece d/s is more common such as in the 4wd world. With our one piece d/s, If you installed one of your ends on the opposite way, then it nulls out your whole "I had it balanced" theory. Mark that shiznit before you take it apart. That would make it out of "phase",, kinda but not exactly.
Marking it didn't really seem appropriate when it was removed (the driveshaft) because the drive shaft,tranny,engine,differential,and pretty much every part of the car came from different vehicles.
As far as a bent axle,I'd think if the axle was bent,wouldn't give me trouble before 75 MPH?,and also,after swapping the u-joints,the vibration still comes up at 75 or so,but then goes away after 80.I need it gone completely.I'm buying new bearings and seals today after work and installing them this weekend (weather permitting) and see what happens.
I get where your coming from on the "everything came from a diff car"
But try flipping the u-joint around on the rear. mabe try another (not sure what that piece is called that bolts the u-joint to the rear) LOL
Maybe you got a bad bushing or loose bolt on a rear arm(s) transferring vibration?
Some have said it is possible for the input shaft of the tranny to do that vibration thing.
Unsure how to diagnose that, Im really helpful.
or tailshaft bushing
It did it with the aod to didn't it? while you got it apart check the pinion bearing for excessive play.
What is the frequency of the vibration? Is it a higher or lower frequency? Can you feel it in the steering wheel?
I've solved a couple of vibration problems by removing the wheels and cleaning the mating surface from the brake to the wheel.
To me, it sounds (seems) like a tire issue. Is it possible one of your new tires has a knot?
I had a knotted tire one time, it would only vibrate right at 65 mph...
Spent an hour changing a rotor and bearings/seals, only to notice a slight knot in the tire as I was putting the wheel and tire back on...
1 new tire later, I was ridin' smooth again...
I'd think with brand new tires, it's quite unlikely...but anything's possible.
If the problem wasn't there before, and the only thing changed is the wheels and tires...;)
I'm hopin it's not something expensive though Vman.
Can't feel it in thwe wheel.I'm going to invest a little time this Sunday.I've been back and forth to my grandmother's a lot lately.
Use the big hose clamp. Did it do it before your new wheels? Are you sure that the wheels are balanced? I hate the front suspensions on these cars. Every vibration I have ever had was one of these two things, or loose/stripped lug nuts.
Everything in the front has been replaced.It did vibrate around 75 and up for quite a while.After I swapped the u-joints,less vibration AFTER 80,but still around 75 or so.I feel it in the shifter handle and the floor,not the steering wheel or pedals.
I bet the part that bolts the u-joint to the rear is out of whack
Tell me more..............
was that part from the rear? or was it from the d-shaft when you put the car together?
you said the shaft was balanced, so it's behind it. did you put the joints in yourself?
I never did it in our cars (yet), did it have to be pressed it? did it go in correctly?
The u-joints went in great,no issues.Only one way to install them,then clips hold everything together.All is still intact.I'm going to crawl under the car and re-check everything.I'll also turn the driveshaft 90 degrees and see if that makes a difference.Then 90 more,then 90 more,then I'm back to where I started.Hopefully once will be enough.
If the vibration changes at all when you turn it. you'll know the problem.
Now I remember, the u-joints have those expanding clips that go inside the ends , don't they.
Yep,THOSE clips.LOL.I'll let you know what happens.
i know you added grease to the zerk until grease poped out the edge of one of the platic rubbers,, right?
also, did you add grease to the caps and double check you did let a needle bearing fall out? you prob didnt though, its just a thought. if you dont roll your finger in the cap to smoosh the needle bearings even along the wall, the cap would have fought you a little going on but sometimes, you can get the cap on and still have needle bearing lying down on the bottom of the cap.,,and still get the clip on.
one time, i had a needle bearing fall into the hole inside the ujoint. had to go fishing with a tiny hooked wire wth a magnet attached.
All was well installing the u-joints,and yes to adding grease as well.
Just a general announcement. Always make sure those clips are seated correctly. A local 03-04 cobra owner didn't and it cost over 2 grand in damage. He was trapping almost 130 when it came apart. Fractured the bellhousing at all the mounting points, shook the lug nuts loose, deployed the airbags and i forget what else....
I checked those upon installation.Little parts that do the most make me nervous about failure,so,they get checked very well.