Sup everybody-I've checked the archives for stuff and I haven't found anything specific even though I have found some people w/ the same prob. I've got a '92 RS-127,850 mi. (this may or may not be relevant, but want to make everything clear) It's been in a front end collision, but it has been "fixed"
So what's goin on?
Well, before I put 4 brand new tires on, it used to shake at around 70 mph-put the new tires on cause that's what the mechanic said it was-well it still did it.
Changed my fuel filter couple weeks ago and it stopped for one drive on the highway-then it started again that next weekend, but at around 75....
And to clarify on the "shaking"-it's all in the front end. I can seed the hood vibriting-my dash shakes really bad, and if I'm wearing a watch on my left hand, I have to drive w/ my right because the rattling gets too annoying w/ my left hand on the steering wheel.
Now I'm thinkin it has to be somethin screwed up w/ the front end or maybe it's just the fact that I've got a butt load of miles....(not as much as some of you -you guys rock) This is really starting to get under my skin because I make a 414 mi. drive-to and from-and three hours in the car about 2 weekends a month-sometimes more- and I can't handle it-I need a smooth ride-at least a smoother ride than that (know the f-bodies aren't known for ridin like caddies...) And on top of this-I've got some 17x9 SS style rims that are goin on my car this weekend-this gonna make it worse???
Sorry for the length and thanks for the help.

 

well, I had a 92 firebird with the same problem. It seems that the springs and shocks were bad causing the tires to wear unevenly, when the tires wore down it caused a shake. I don't think this is your problem, but I once had a friend with a very similar problem to you, we found out that one of his rims was slightly bent, unoticeable to the naked eye, but bent enough to cause a shake in the front. Try the new rims and if it still shakes we'll think of something else.

 

Check your wheel bearings. Then get an alighnment.

 

I have this problem with my car too, I have balanced my wheels myself so i know they're right. My best guess for mine is the driveshaft, it shakes everything, I even have the same watch problem!

 

Spin balancing the tires is a good start. Then get the alignment. Then start changing suspension parts. Out of balance tires will cause a vibration at 45mph and 75 mph most of the time. If the suspension is bad and the tires are "cupped" then rotating tire front to back will help you to isolate the problem. Good Luck!

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87 TA, 305 TPI, Custom CAI, ACCEL 8mm wires,ACCEL Super-coil, ACCEL Plugs, JET TPI Airfoil, Cherry Bomb Muffler
"35 yr old helo pilot
with a cool new toy my 17 yr old son wants" The Phoenix Project..click to see my project car
Trans Am stuff and GIRLS, GIRLS, GIRLS!!!!!

 

Isn't the watch rattling the most annoying thing in the world? Try to listin to that for over 3 hours.......Well- a lot of people keep talkin about wheel problems, so I'm gonna put on my brand new 17x9 SS rims and see if that corrects the problem-if that doesn't fix it, I'll check on the other stuff you guys have so graciously informed me about-thanks for all the help-I'm sure I'll be back if it doesn't work

 

Bad/loose/worn wheel bearings can cause that problem also.If changing wheels/tires don't help,try the bearings.

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'91 RS, 375hp 350
New paint-solid black
ROH Snyper wheels-17x9 wrapped in 275/40/17
ASCD SS hood, High-rise Z-28 spoiler,shaved handles/antenna,
Hooker super comp 1 3/4" headers,dual 3" exhaust,two 1-chamber Flomasters,machined hi-perf GM heads,Holley double pumper 650 w/50cc pumps,Power Plus 360* high rise aluminum intake,Edelbrock Elite valve covers/14x4" open air cleaner,Mallory AFPR,Proform HI-perf HEI disributer with curve kit,Crane 292 cam,Eibach Sportline springs,KYB struts/shocks,completely rebuilt steering linkage,36/24mm sway bars,12.7 steering box,wonderbar,145 gauge cluster,Auto meter gauges,dual guage A-pillar pods,180* thermostat,dual push/pull cooling fans.
75-125 shot NOS system planned.

President-Austin 3rd Gen F-body c.c. - message board at
www.hpsmotorsports.net
See my car and others at www.ride4life.net

 

Could also be a worn tie rod. I had that problem on my old Escort. Yes, i know, totally differnt car, but after I replaces the tie rod, the vibration was gone.

 

Could it also be a bent axle? I have a vibration at 80 MPH, and i can't seem to chase it. I have had the DS balanced and new tires... i now just stick below 80 and its fine.

 

rotors in a fast car with a good brake system can warp them easy,just happens my grandpa has that problem with his caddy. new brakes n rotors ever 18 months.



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http://PCperformance-usa.com/86bird/86bird.html

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have you checked the driveshaft u-joints or checked the driveshaft for any possible causes that would make it out-of-balance?

 

Ive replaced my tires, rims, rotors, brakes, wheel bearings, struts and i still get a vibration at speed... ive done about 4 alignments, i get them free, what else could cause this problem maybe a outa round driveshaft ?? Plus my steering wheel has play in it, a decent amount, and still wants to pull left on the road, i push on the breaks then it shoots the other way, then when i get way slow it will turn to the other way... very confusing any help would be really appriciated !!

 

Try replaceing your A arm bushings they rot out form age.

 

all right ill try that, should i just get a bushing set, or what here is the link for the list of the front end what should i order.. https://www.thirdgen.org/forums/susp...readsheet.html

 

 

I know its the car, i can feel the front end like jerking around, its hard as hell keeping it going strait, not to mention it makes me look like im drunk when im driving which i dont want any attention from the cops lol, i have a good amount of play in my steering wheel also, i belive that if i got a bushing kit for the front end it should help.

 

question......does anybodies thirdgen ride smooth (ALMOST like a caddy)? My 3rd gen over 55mph is JACKED up......It feels like all of my organs inside my body are rattling all over. I have 2 brand new tires in the front.. that didnt help. Got new shocks-KYB- that didnt help. still have the old springs..

this car cost millions to keep up with

 

Mine rides smooth. until I hit about 105, then it gets kinda scary. I'm sure once I finish replacing the stock 18 yr old suspension it'll ride better, but i'm also making stiffer. It's gotten a LOT better at high speeds with the 36 mm sway bar.

 

so there is hope....

it basically comes down to overhaulin the front end.....

 

My car seriously rides like a caddy. It just floats everywhere... I have a vibration (Very slighty) just from the L03 humming along... but other than that I feel like I'm riding a cloud... It's really irritating. My shocks/struts are trash apparently because I can feel the car wallowing around over bumps or even hills.

Got some IROC springs and Konis ready to go in at any minute to change all that in no time. It's gonna ride like a skateboard soon!

But if anyone wants a car that rides like a caddy, I'll sell ya my old struts/springs.

As far as Im concerned, my RS rides REAL smoothly. A little TOO smooth.

 

I thought he was refering to smooth as in no jerking and vibrating. If you want smooth like a cloud floating down the highway then soften up the front springs. Mine does alright, but as I said I'm getting ready to (as vortex said) make it ride like a skate board. I've got a set of V8 lowering springs to put under my V6. If that doesn't give me what I want then coilovers are my next step.

 

Tighten your steering box, it's a 9/16 and an allen key. Crank the wheel all the way to one side, and bring it in about 1/2 turn. Should help a bit, helped me out a ton.

 

My car used to shake like that.I eventually rebuilt the whole front end except for ball joints.Checked evrything.wheel bearings,rims,tires,balance,roters rechecked whole front end,driveshaft,nothing fixed it.Decided to go ahead and replace the ball joints.That fixed it.My problem was eating up my 245-45-17`s on my SS rims.I even got rid of them thinkiing was something wrong with the wheels.Are your ball joints original?

 

Did he end up getting it fixed? Does the vibration show up more in the steering wheel or the body of the car? If it's in the wheel, you'd probably want to look at horizontal parts more such as worn rod-ends. I picked up a cheap Harbor Freight dial indicator($9) for checking axles and hubs.
Be sure to check your tranny mount and maybe the pinion angle also.

 

yea i had the same problem...wheel bearings were jacked...got new tire rods also when i got my alignment, and now...i have no shake on the highway

 

drove my car 60 miles today at 60-70 MPH today, felt pretty darn good.

Setup:
Iroc Springs
GR-2 shocks/struts
36MM hollow swaybar
poly swaybar bushings
poly end-links
wonderbar
sfcs
tubular LCA's
lca relocation brackets
new tie rods,centerlink, idler arm
new rag joint
17x8 zr1s, kumho/nitto mix
LS1 aluminum driveshaft

things i need to get:
new gearbox
axle bearing
wheel bearings

 

i will get me some new wheel bearings and ball joints and a fresh alignment....that seems to be the popular symptom here. anybody have an idea on the total cost i should be looking at:

labor and parts on:

wheel bearings, ball joints, new pitman arms, and new tie rod ends???

 

parts minus the pitman arm will run you about 200 bones. labor is gonna vary based on who and where you're having this done. I've seen alignments go for around 50-70 dollars.

As to the pitman arm, i've never seen them for sale new. An idler arm goes opposite side of the pitman arm and goes for 30 as well.

don't forget to throw in a wonder bar if you don't already have one! its a must!

 

the last time i got an alignment i needed a pitman arm and it cost me like $150 or so. That was at a Firestone store though about 2 yrs ago or so.

When i got my 36mm sway bar the guy gave me the wonder bar too, but i couldn't get it to fit. the bottom of my radiator got in the way. is this a designed feature or was i just being a dumbass?

 

did you try rotating it 180?

 

To my memory I tried every which way I could think of. It was like 2 yrs ago. I just hadn't really thought about it since. If I remember correctly I believe it was the lower rad hose was the problem, but I also didn't know what the hell it was when he gave it to me. Being young and dumb I was like, OK thanks, and didn't even ask.

 

what is a wonder bar