My 77 developed a severe wobble felt through the steering wheel at speed. It's not always at the same speed and comes and goes intermittently. Happens on the straight somtimes but always in the corner and gets worse to the point it's all over the road. I only have aboutr 300mi on the alignment with new ball joints outer tie rods and all new bushings. I did change the tension rod bushings this year and drove the car with no problem. Then all of the sudden the wobble shows up. I had the tires re-balanced and even rotated them . Shop did not think belts were separated and looked true. I have everything torqued to spec and at this point don't know what it could be. Could I have thrown the alignment out that bad with tension rod bushings? It drove fine last year after replacing the front end parts before it was even aligned. Thanks,Jim

Wow. Sounds like you've already replaced everything I would suspect.

Could you have thrown a weight on one wheel? Do you have spacers or lug pattern converters on the front end?

I'll be thinking of this, trying to picture what else it might be.

How about the wheel bearings. Check for excessive play. New bearing will wear out very quickly if the were over torqued.

Also check the rear suspension, and axle. a problem back there may feel like a front end shimmy.

Good luck
Pat

_________________
Pat & Regina
Current Inventory
73 240Z Gray (in fostercare)
74 260Z White project car (back on the road)
74 260Z Brown triple webers
75 280 Z stroker
82 280ZX
91 300ZXTT
12 370Z Black

Stock turbo wheels balanced yesterday and shook like heck on the way home. Pat ,I jacked up the car and shook the rim/tire. No play side to side or top bottom. Could they still be worn ? The only thing I did find was a questionable bolt which may be the problem. It's on the driver side rack bushing cap . I took it out and the threads are beat . Cleaned the threads on the cap with a new bolt but would not hold. For now I will bolt it from above until I can find a new cap . Thanks,Jim

With the car jacked up. See if the tire and rims spin true.

Check front and back

Rotate tires front to back see if it get better.

Pat

_________________
Pat & Regina
Current Inventory
73 240Z Gray (in fostercare)
74 260Z White project car (back on the road)
74 260Z Brown triple webers
75 280 Z stroker
82 280ZX
91 300ZXTT
12 370Z Black

Rotated tires after balance with no luck . They seem to spin true to my eye for what it's worth. Tomorrow I'll get the rack back in with new bolts to see if that was it . If not I may just change the front bearings as I have a set already. Thanks,Jim

not much left you can replace...
but just because you've got new parts doesnt mean that there perfect.. sometimes brand new parts can be duds.... i hate that...

For the heck of it I decided to check the measurements from tread to tread on front and back of the tire . It's out 3/8" , could that be enough to cause the problem? I don't remember hitting anything after the alignment last spring but who knows. Thanks,Jim

Jim, as long as this remains a question of diagnosis, I'd recommend taking it straight back to the guys who balanced the wheels for you last week and accuse them of doing a lousy job.

They will examine the whole car and tell you why is isn't their fault, and you'll get a free diagnosis!

At least then you'll know what to work on.

Frank

They are going to look at it on Tuesday so hopfully it is a simple fix as I am out of ideas. Jim

Well, for what it's worth, here's what the 1970-78 HAYNES manual says:

SYMPTOM: Wheel wobble and vibration

REASON/S:

Wheel nuts loose
Front wheels and tyres (sic) out of balance
Steering ball joints badly worn
Hub bearings badly worn
Steering gear free play excessive
Front springs weak or broken.

Since you've replaced most of this stuff last year, aligned it 300 miles ago, and balanced the wheels just a few days ago, I'm baffled. Whenever it happened to my 240 it was usually a tire separating, bad Toe-Out adjustment, or a front wheel bearing. Only once was my brake rotor to blame, but that stymied me like this is doing to you (two-speed wobble, even on straights, only wobbled when turning right, couldn't feel it thru the pedal until a few hundred miles more).

I dunno!

*(BUT ~ I would make one suggestion. I was never able to jack the car and spin the wheels to judge their integrity by eyeballing them. Remove the wheels and roll each one down the driveway. If there's a wobble in one, try replacing it with the spare for a test drive. If that solves your problem, you've isolated the culprit).

Frank

Check to make sure the caps on the tops of the struts that hold down the strut inserts have not loosened. If you slip a thin pair of channel lock pliers between the coils you can see how tight they are.

You may have a bad shock insert as well.

-Bryan

_________________
Bryan Little
Datsunzgarage.com

1970 240Z - enhanced F54 L28 w/P90, Weber DCOEs, 4:11 R200, Nissan T5 5-speed

Would he have to compress the shock to check that? Can the car be on the deck, or do you have to lift it and compress the spring?
Frank

Frank,Bryan I went through the items you have listed and it all seems ok. I replaced strut inserts 2 years ago .I'm starting to lean towards a bad tire because the problem came up out of the blue without hitting any potholes . It just happened one day when I took the car out. I did rotate the tires so could all four have failed? They were on the car when I got it so approx 6 yrs old , who knows. No shake in the wheels when the car is off the ground and rotate freely . I'm having the shop double check the front end parts just in case . The steering rack was on my list for next year so I may just order a rebuilt . I need to fix this before next weekend . Thanks,Jim

You could be right and the tires are simply old.

I remember years ago the Z Doc I went to would take new tires on the rim and run them on a lathe. He claimed that the seam where the belts come together creates a minute high spot, which would cause the tire to bounce minutely on every revolution.

So he would hold a sharp blade next to the tread as the lathe turned and take off a mm or so on this "high spot"

I had him do mine and on the road the tire balance was so smooth the car felt like it was driving on glass. The effect only lasted a few thousand miles until the tread wore some, but the effect was real.

BTW Frank, if you jack up either end of the car, it decompresses the coil enough so you can slip a thin pair of pliers in between them. Last year due to Whitney Ave here in New Haven which was the worst road in New England, I found my RR cap actually loose and jingling inside the spring...so it can happen.

_________________
Bryan Little
Datsunzgarage.com

1970 240Z - enhanced F54 L28 w/P90, Weber DCOEs, 4:11 R200, Nissan T5 5-speed