75 +mph shaking Dash / steering wheel

[mike95sho]

Hey all I couldn't find an answer with the search so I figured I'd ask for once.
So I don't drive the SHO much. While travling to a cubs game at 75-80 MPH my the cars Dash shakes and steering wheel. So I felt a lil unsafe and kept at 65 MPH. It's a 95 ATX with 140K miles (Highway commute) Eibach springs and Motor Craft struts aboue 30k miles ago. The car is do for an Alignment. Just wondering if you think this is all I need? or is there possible more of this? I don't understand Ball / CV joints as being a sub-novice Mechanic, but I'm thinking your gonna say they are a possible worn.

 

[Machspeed]

Tires prolly need balancing.

 

[SHOtimer]

How old are your tires and are they cheap? If the tire is cracking between the tread and on the side they need to be replaced as a tire in that bad of shape won't hold a balance. Sounds like you just need a new set of tires, or if they are fairly recent and in good condition have them rebalanced.
Doug

 

[sdpatt]

Have your tires balaned with the centering cone installed from the back (hub) side of the wheel. The Motorcraft struts with the Eibach srings probably give you a pogo-like ride, don't they?

 

[mike95sho]

Tires: Checked my records. I Purchase / rotate with Discount Tire co.
Hmm 215/60R-16 94v Dublop SP SPort 5000.
Last time I was their March 2003. I purchased the WRX June.. so Im guessing about 3.5k miles since last Balance / Rotate (Darn miles not on Invoice). 1 tire is supa new replaced under warrenty other 3 are great condition (I did look in the dark but they felt just fine) in my mind as Car is only driven on highway.

sdpatt
Member # 51 posted September 04, 2003 10:44 PM
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Have your tires balaned with the centering cone installed from the back (hub) side of the wheel. The Motorcraft struts with the Eibach srings probably give you a pogo-like ride, don't they?

Hmm I can agree with that lol. Tonko or what not were not availble when I purchased struts so I had to go with Motor Crap.
I'll mention the Center cone tommorrow morning when I have tires Rebalance'd and then Take car for a SPin on highway. THanks for Fast reply you guys are great!

<small>[ September 04, 2003, 11:35 PM: Message edited by: mike95sho ]</small>

 

[WakaShoMan]

The vibration you get is because the tire imbalance if resonating with your suspension at apeed. One way to avoid it is to do as you did, which was to slow down to 65MPH to avoid the resonant peak.

An alternative way is TO SPEED UP. Think of the resonant peak as analogous to "cracking the sound barrier".

 

[jelloslug]

Tires are the only thing that will make you car shake like that. I had a bad tire on the back and it made the car feel like it was going to come appart. eek!

 

[mike95sho]

WakaShoMan:
An alternative way is TO SPEED UP. Think of the resonant peak as analogous to "cracking the sound barrier".

Sh$t! When I get the chance to drive in to Chicago, I love getting a lil agressive in the SHO on the 3-4 lanes of I-90. Lol so new moral is: When car is shaking at 75, better do about 95 to smooth her out. Time to head off to the shop for Balancing! Thanks again

 

[Blue-By-U]

I'll attribute your problem to the tires needing to be balanced or worn inner/outer tie rod ends. It doesn't hurt to prop up your car and check your wheels for left/right or up/down wiggles. How are your subframe bushings?

 

[91 SHOplus]

WakaShoMan:
The vibration you get is because the tire imbalance if resonating with your suspension at apeed. One way to avoid it is to do as you did, which was to slow down to 65MPH to avoid the resonant peak.

An alternative way is TO SPEED UP. Think of the resonant peak as analogous to "cracking the sound barrier".

my 91 gets the shakes at 75. If I do 70, she's fine. If I do 80, she's fine. If I do 75, she shakes the fillings outa my teeth! eek!

 

[91 SHOplus]

BTW, not being a tool or anything, but just a note: Your sig pic is too big. It can be no more than 300 pixels in it's widest direction, and under 25k in file size.

 

[mike95sho]

Balanced. Problem Solved. Took car to 100 (Man I love the SHO. I can't part with it. 25k Subaru sits outside SHO Garaged!) and let it coast down to 60 no shudders.
Testing pic also. I'm more of a computer gamer. Things like Photo CHops / UBB / Hotmail codeing are a Mystery to me. But when I need to take on a **** tank and I just have grenades and Automatic weap, that's no sweat (Battlefield 1942 is the game)

 

[Doug Waschenko]

Mine starts at 70, dash bounces.
I am the original owner. I brought the car in for service and the dealer wouldn't fix it because the mechanic wasn't permitted to drive over 55 to verify the cause.
That was 90,000 miles ago.
I don't remember how many tires, one set of ball joints and one set of tie rods.
I just had a new front bumper cover and hood put on the car and walla, no more vibration.
I think that maybe this might have been aeordynamic and that maybe the nose wasn't attached from the factory right?

 

[sdpatt]

If your car is shaking, the tires are not balanced. It takes a dynamic imbalance to create the shake that is tire-speed dependent. getting the tires properly balanced will correct 99% of the shakes you guys find. Only a badly out of round or defective tire will cause the other 1%.

 

[Nook]

tires MOST likely, but could be any other rotating assembly, a effed rotor, rim, we just replaced a hankey halfshaft on teh right that was giving the same problem, not sure how it got messed up, but the right outer halfshaft was causign the same problem.

N