Front shaking in fast turn

[guy_geo]

Tokico illumina

Nissan motorsport coils springs

Urethane bushings chaged all the way in the front

Black dragon front sway bar

Quick knuckle steering

Toyo SPT 195/60/14

Here's the situation..

When I accelerate to take a freeway ramp, the front end starts to shake as soon as the builts speed.. I can feel vibration in the sterring wheel..

Front alignement is ok..

Any idea what could it be???

I'm planning to install soon my rear sway bar, maybe it will solve the problem???

[Seppi72]

I had a similar shaking occur in my '72 while making moderately quick turns shortly after I replaced all the bushings with urethane. It turned out that the bolts holding the lower control arm to the front strut were backing out. I didn't realize what was happening (even after stopping to check things out) until too late. First, one bolt fell out and the strut was free to rotate when under a certain level of side load (the shuddering). When the scond bolt fell out (fortunately at about 25 MPH), the entire strut was free to swing around in the fender well and banged the sheet metal up pretty good. No tremendous damage, however.

These bolts are now safety-wired on my cars.

[Force Fed]

Could be a tire out of balance also.

[guy_geo]

Could be a tire out of balance also.

Weel, it would be shaking in straight line no???

[guy_geo]

I had a similar shaking occur in my '72 while making moderately quick turns shortly after I replaced all the bushings with urethane. It turned out that the bolts holding the lower control arm to the front strut were backing out. I didn't realize what was happening (even after stopping to check things out) until too late. First, one bolt fell out and the strut was free to rotate when under a certain level of side load (the shuddering). When the scond bolt fell out (fortunately at about 25 MPH), the entire strut was free to swing around in the fender well and banged the sheet metal up pretty good. No tremendous damage, however.

These bolts are now safety-wired on my cars.

I will check the bolt tonignt to be on the safe side.. if the rain can stop...:mad:

[rxsleeper]

Just a thought if it is not tire balance, Wheel Bearings? At lower speeds you might not notice it until you hit a bump. When you shift the weight to the rear under acceleration it should be more noticible. Also, I have seen a "shake" from a tire that had not worn evenly. Rotate the tires and see if it persists.

Good luck....

[jmortensen]

Tire balance, wheel bearings, ball joints, tie rod ends, or something loose. Ball joints and tie rod ends are pretty much guaranteed bad if they haven't been replaced in the last 10 years or so, and people often overlook them.

Tire balance is surprisingly hard to get right it seems, it's something that many shops do a horrible job at. Probably has to do with the lowest man on the totem pole doing the tire mounts and balances. Also people have an affinity for the wheels which have no lip on the outer edge to hold wheel weights and they don't like the stick on weights because they're ugly. You need weights on the inside AND outside of the wheel to dynamically balance a tire.

[guy_geo]

Tire balance, wheel bearings, ball joints, tie rod ends, or something loose. Ball joints and tie rod ends are pretty much guaranteed bad if they haven't been replaced in the last 10 years or so, and people often overlook them.

All of these have been replaced less than a month ago.

Wheel bearings also were check, all are ok..

I suspect the tires.. but I will check for the wheel weights.. One may be missing on the wheel....

[Force Fed]

What kind and size of tire? Is the steering wheel actually moving, or can you just feel vibration in it? Could be there's something in the rear causing a vibration, bad rear wheel bearing, worn rear suspension bushings, tire rubbing a strut (front or rear) due to cornering forces, etc. Did you just have the front aligned, or did they check 4-wheel alignment?

[guy_geo]

Fornt wheel alignment, since we cannot have rear alignment on our 240Z.

All the suspension parts were checked, the steering wheel is shaking, not on tight ramps, but on the long smooth curvy ones..

Like I said previously,:

Tire balance, wheel bearings, ball joints, tie rod ends, have been replaced less than 2 months..

Tire size is 195/60/14

All of these have been replaced less than a month ago.

Wheel bearings also were check, all are ok..

[240ZX]

You may want to check tolerances in the steering rack and the small U-joints on the steering shaft along with the rubber steering shaft coupler!

Tom

[Rockr69]

I'd say it's the rack bushings and the coupler on the steering shaft. I had the exact same problems. I replaced the rack bushings and the coupler and the shaking was gone!