vibration...yes I searched first

Tommy Turbo

Registered User
I have only had this car a short time, and since It had sat for a long time I think with the previous owners (tires had a date code of 2001), I just figured the vibration was due to the tires.

I had gone through and replaced all the struts/shocks with new tokico illuma II's, all new ball joints and bushings, and got a alignment. Got new tires, and still have the same vibration. It comes on strong around 70 mph.

All the searches point to the drive shaft, or driveshaft bolts. I crawled under the car today, all bolts are tight, and the universal joint and rear axles all look fine.

The vibration seems to be in the whole car, but in the steering wheel too. The vibration in the wheel is like a pulsating shimmy. The vibration through out the body just makes the plastic vibrate. seems fine and smooth until 70. When it starts it makes the car feel like it is disconnected from the road, like it's bouncing around, very squirley. There isn't much of a change between firm and soft ride settings.

Where should I start? I read about running the car up on jackstands, and looking under to check the driveshaft, but I just wasn't too wild about doing that since my driveway isn't super flat.
 
Does it have any noise to go with the vibration? It sure sounds like tires out of balance or out of round. Did you remove the DS and check the u-joints, a lot of times they look fine but once you take the shaft out the joints are tight/bound up.
 
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no there are no noises, and the tires are brand new, I've gotten plenty of tires from this place and have never had any trouble with them not balancing tires properly. the car had vibration before the tire change as well. I guess I could go back and have them recheck the tires.

I didn't remove the shaft, as it looks like I'd have to drop the fuel tank, and wanted to find out more before getting involved with that.
 
ive put over 250 k miles and never had ujiont trouble because they are so straight in line .my drive shaft bolts came loose once and caused a very fast shuttering . but you said that was all good , so im thinking bad tire or bent wheel . you can mostley tell a drive shaft problem the vibration is very fast more like a shuttering noise compared to a tire or brake rotor shaking

ralph
 
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my 90 automatic seems to have more engine viberation at around 2500 rpm at certain speeds than the 89 5 speed . but i just count it as normal the car has run fine for the last 10 years

ralph
 
Just as a note - the U-joints were bad in Ruby Jean (my 1991 Cougar) when we bought her.

Pulled the drive shaft, one side was hard to flop by hand, the other would "CLICK" like a detent (think of a ratchet wrench clicking!).

With a 3.08 rear end, we got vibes at about 35 to 40, and worse at about 70 to 75 (as fast as I ever took it until I found out about the drive shaft.)

There's been posts here and on TCCoA on the best U-Joints to use (I think the better posts here, but I'm not sure).

You can drop the diff and pull the drive shaft - I've done that. With a tranny jack under it, it's even possible to do a drop-enough-to-pull on the diff without pulling the half shafts out.

RwP
 
Have the caster checked on an alignment rack. I'll bet it's a simple fix like that. I went through that same issue for six months, chasing the 70 mile an hour shake and vib. problem. The kids doing the alignment never did the caster. My .02 cents.
 
Had the same thing on my car. Around 70 the mirror vibrated and you couldnt hardly make out the car behind you. Turned out to be ballance of the tires. They were ballanced when installed but when checked out again it wasnt even close. Vibration went away when I had it redone by someone who knew what they were doing

Ken
 
I had the alignment guy do the caster, I actually watched them do the whole thing. Caster is set at the specs listed on the site, +5 on the drivers side and +5.5 on passenger side, with -1 of camber on all for corners and both front and rear toe set to .20 toe in.

I've got to get back to the tire place and have them re-balance, but I have a feeling the tires are ok. I had the old tires balanced too, and It didn't seem to help. I just figured the dry rotted tires from 01 were the cause.

If that doesn't fix the problem, I guess I will look into the driveshaft and u joints.
 
Have you checked the rotors to verify they are still shaped properly? Usually the brakes tell you, but I have seen them just out enough to cause vibration when rolling alone and not really be bad when the pedal is applied.
 
funny you mentioned that, but I had the front rotors turned, because they were warped and the steering wheel would shimmy under braking.
 
I'm having the same vibration problem right now...symptoms suggest vibration is coming from the rear...pretty much everyone is hitting the nail on the head

I did brand new driveshaft , new differential & mount, rebuilt housing, new half shafts, new wheel bearings, new wheels/tires, new bushings on LCA...Havent replaced UCA bushings, shocks, or rotors yet...

I was reading that the geometry angle from the tranny to the Diff has to be in a certain range...I think within 1* of each other...maybe aftermarket mounts on tranny and diff screwed this up...?

keep trying....let us know what happens...I will post as soon as I fix mine:mad:
 
What about the tie rods? The inner bushing on mine were shot where they meet the rack. It doesnt take a lot of play to throw things off. You should be able to feel where its coming from. My motor mounts where like dust too. That made a major difference. Trans mount as well. Just some stuff incase its not the tires
 
tie rods inner and outer are all new. Everything in the front suspension is new, bushings, ball joints, all struts shocks. I will look at the motor mounts, but I haven't noticed the engine sitting on the cross member like some people have mentioned, but will look at them again more closely. I'm hoping to look this weekend, it's hard to do much during the week with work and all.
 
The front strut bars(run from the lower control arm to the frame on the car) have been put in wrong before causing harmonics in the suspension. When the nut gets tightened sometimes the bar gets turned and is not turned back.
I dont have a pic to post with it, but seen this cause issues along with the struts themselves not being settled after being installed with new isolators. A few hundred miles and they settle in.
 
can you post pics of the correct ways these have to be put in? I'm pretty sure things all got put back correctly, but am if I have some pics to compare to then i can check. I'd say I have put about 150-200 miles on the car so far since rebuilding all the suspension.
 
well, after replacing the harmonic balancer, and motor mounts / trans mounts car is finally smooth at speed.
Damn it took long enough to get to this point. Anyway just update.
 
So it had nothing to do with the balance or suspension, just curious because i have the exact same vibration
 
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