280z Steering Wheel Vibration

[Ownallday]

I know this has been discussed in the past but the solutions haven't worked out for me. I have a 1978 Datsun 280Z. Pretty much all the bushings have been replaced with polyurethane. I have replaced the inner and outer tie rods, front wheel bearings, ball joints were replaced 2 years ago less than 5k miles. I have tokico lowering springs, I also have technotoytuning front and rear control arms. I also have a momo steering wheel. I have a pretty bad vibration coming from the steering wheel. I should also add that I've balanced the tires at least 5 times at this point, and the alignment has been done although I do have about -2 degrees of camber front and rear camber left side is about .4 degrees off compared to the other side which is most likely causing my car to pull to the right. Any other solutions. I do believe my struts are blown but to my knowledge blown struts shouldn't cause vibration. Possibly driveshaft? The car does have the lovely clunk in the rear when accelerating from a stop. I can't tell if there is play in the u joints/half shafts but there is play from the yoke inside the driveshaft (I can rotate it a couple degrees) not sure if that's normal. Any help would be appreciated. Below is a video of the the steering wheel vibration looks like at approximately 65mph.

 

[Mark Maras]

 I've never had a steering wheel vibration that was caused by anything than a problem in the front. I did chase a severe vibration in the body (85 mph +)(not the steering wheel). I installed six u-joints but didn't cure the vibration until I found a small dent in the prop shaft. I believe the clunk and steering wheel vibrations are two separate problems.

[jfa.series1]

You've addressed quite a few of the possible vibration issues but you didn't mention how old your tires are. You may have flat spots or out-of-round conditions not detected or cured by balancing, also possible slop in the steering rack. These cars are extremely sensitive to all of these issues. As to the rear end clunk, you likely have a failed differential mount. Get the car on a lift and see if you can move the front of the diffy up and down. Be cautious about getting a replacement solid mount that does not have the rubber insulator.

[Pop's Z]

Years ago when I worked in a tire shop we static balanced and re-balanced a customer's car because it had a vibration at speed. We finally re-balanced the tire on a machine that could go up to 80mph. That worked. Now I don't know whether or not that can be done today, but it might be worth a try. Your vibration looks like a tire issue. Have you tried switching your tires front to back?

However, I had a vibration like yours on my Zed and traced it to a bad wheel bearing. No matter how I tightened and re-tightened it just kept coming back. I finally replaced all the wheel bearings, torqued them to spec, and the problem went away. Hope this helps. Good luck.

Cheers, Mike

[Ownallday]

2 hours ago, Mark Maras said:

 I've never had a steering wheel vibration that was caused by anything than a problem in the front. I did chase a severe vibration in the body (85 mph +)(not the steering wheel). I installed six u-joints but didn't cure the vibration until I found a small dent in the prop shaft. I believe the clunk and steering wheel vibrations are two separate problems.

Noted, I was leaning slightly towards the driveshaft anyways as my next solution. I have no idea if it's ever been replaced so it won't hurt to replace it. I heard the clunk can sometimes be caused by the driveshaft and possibly the axles.

1 hour ago, jfa.series1 said:

You've addressed quite a few of the possible vibration issues but you didn't mention how old your tires are. You may have flat spots or out-of-round conditions not detected or cured by balancing, also possible slop in the steering rack. These cars are extremely sensitive to all of these issues. As to the rear end clunk, you likely have a failed differential mount. Get the car on a lift and see if you can move the front of the diffy up and down. Be cautious about getting a replacement solid mount that does not have the rubber insulator.

The tires are about 1 year old, less than 7k miles on them. The tread is pretty much 80% on them. I use to have movement in the steering rack but went away after replacing to polyurethane bushings. I can't remember if I've replaced that mount or not. I know I did the moustache bar mounts though. I'll most likely order a oem diff mount that be safe eitherway.

1 hour ago, Pop's Z said:

Years ago when I worked in a tire shop we static balanced and re-balanced a customer's car because it had a vibration at speed. We finally re-balanced the tire on a machine that could go up to 80mph. That worked. Now I don't know whether or not that can be done today, but it might be worth a try. Your vibration looks like a tire issue. Have you tried switching your tires front to back?

However, I had a vibration like yours on my Zed and traced it to a bad wheel bearing. No matter how I tightened and re-tightened it just kept coming back. I finally replaced all the wheel bearings, torqued them to spec, and the problem went away. Hope this helps. Good luck.

Cheers, Mike

I heard of something like that, I work at a Toyota dealership so I have the luxury of balancing the wheels. I have tried rotating the tires already and there isn't a difference at all.

I replaced them about 3 months ago but I will go ahead and recheck the torque on them. Last time I did it I remember torquing them properly. Thank you for the input. I'll see if I can find a better balancing machine shop.

[Yarb]

Do you feel play in the rack itself? I see where you changed the inner and outer rods. Had a 240 years ago and the issue was the rack it self had slop in it. Just throwing another variable out there.

[Ownallday]

6 minutes ago, Yarb said:

Do you feel play in the rack itself? I see where you changed the inner and outer rods. Had a 240 years ago and the issue was the rack it self had slop in it. Just throwing another variable out there.

Aside from inner and outer tie rods and poly bushings for the rack and steering shaft, I haven't touched anything else. I can't feel or see any play, I tried moving the tires side to side and no free movement from the rack or wheels. I checked this after I did my inner and outer tie rods. Originally the rack had play and after doing those two things the play went away.

[Yarb]

That’s a good thing. Is it more of a vibration or a wheel shake your feeling?

[Reptoid Overlords]

Are the tension\radius rods from the lower control arms to those brackets on the frame of the car tight?  I had one come loose once and caused a vibration, although it became apparent at lower speeds and had a severe pull to the side of the affected loose tension rod.  My car is a ZX, but as far as I can tell, the S30 has a similar setup.

[Ownallday]

1 hour ago, Yarb said:

That’s a good thing. Is it more of a vibration or a wheel shake your feeling?

It's mostly in the steering wheel, the car has a super slight vibration from the car itself which is where I think the driveshaft might be causing that there or possibly my blown struts. Or just the more stiff suspension setup I have too. Not really sure.

 

37 minutes ago, Reptoid Overlords said:

Are the tension\radius rods from the lower control arms to those brackets on the frame of the car tight?  I had one come loose once and caused a vibration, although it became apparent at lower speeds and had a severe pull to the side of the affected loose tension rod.  My car is a ZX, but as far as I can tell, the S30 has a similar setup.

Yeah the s30 has those tension rods. I last checked a couple months ago but I checked the tightness with the car in the air, today I'll double check the tightness on those on the alignment rack. My car does pull to the right.

[heyitsrama]

I was chasing a stupid shimmy like this a couple months back, IIRC the lug studs on my drivers side sat too far out and were not engaging properly. Pics in this thread:

 

[zKars]

One more possibility. I chased a bad vibration for over a year until, almost as a last resort, i checked the spacers I was using on the front wheels. They were only 3/8 or a 1/4 thick, but they were SO BADLY MADE (cheap cast pot metal) that their thickness varied SO much that the wheel had enough run out to cause the vibration. Bought some 1/4 aluminum flat plate, drilled the damn holes myself and TOTALLY solved the steering wheel vibration.

Bent or out of round rims can also cause the run out too.

Just jack the car up at each wheel, rig up a pencil or something to “just touch” the rim near the edge and rotate the tire and watch the clearance to the pencil tip as the tire goes around. Should be dang near no variation, maybe 0.05 at most. A runout gauge is the best thing to use of course but just as a check you can almost hold your finger there and check.