280z Steering Wheel Vibration

[mgood]

I had a vibration in my 1976 car after I hit a pot hole and blew the tire the fall of 76.  I chased it for at least 2 years and the dealer said it was a bent front axle, so they replaces the whole strut and I still had it for at least 10 more years.  I finally checked the hub that had the baring outer race and it was spinning in the hub.  I replaced the hub and most of it want a way,  finally moved the aluminum wheel (original Appliance) from the front to the back (the wheel did have a small amount of movement from the pot hole on the outer rim) and purchased new 205 70 14 tires and all gone now except at about 70 mph.  I don't drive that fast too often so I'm good.  Good luck with you hunt.

[ETI4K]

I also have chased the elusive, speed-sensitive steering wheel shake.

The problem came directly from a wheel-balance problem - BUT! it's not as simple as just rebalancing.

The problem was the wheel weights were not distributed symmetrically about the imbalance.  Since any balancing process will never be absolutely perfect, the slight inaccuracy of this particular balancing effort worked very well up to about 55mph.  Above that speed, the car acted as though it would explode.  Definitely hit a resonant frequency.

If the weights had been selected and applied more carefully (shall we say?), the inaccuracy would have been significantly reduced.

In the end, a perfectly acceptable balance was achieved by using bolt-plate balance fixture as oppsed to the typical centered balance fixture.  The difference being each wheel is balanced based upon its mounted center.

 

[Ownallday]

On 4/17/2022 at 12:51 PM, ETI4K said:

I also have chased the elusive, speed-sensitive steering wheel shake.

The problem came directly from a wheel-balance problem - BUT! it's not as simple as just rebalancing.

The problem was the wheel weights were not distributed symmetrically about the imbalance.  Since any balancing process will never be absolutely perfect, the slight inaccuracy of this particular balancing effort worked very well up to about 55mph.  Above that speed, the car acted as though it would explode.  Definitely hit a resonant frequency.

If the weights had been selected and applied more carefully (shall we say?), the inaccuracy would have been significantly reduced.

In the end, a perfectly acceptable balance was achieved by using bolt-plate balance fixture as oppsed to the typical centered balance fixture.  The difference being each wheel is balanced based upon its mounted center.

 

So the problem was mostly the wheel balance, I rebalanced the wheels and used road force and found the wheels were out of balance when using road force compared to just spinning. This solved about 50%-70% of my shaking at the steering wheel at least based on todays test drive. I now believe the rest of the shaking might possibly be coming from either the hub or struts. You can literally push the struts in with your pinky zero force and they don't come back up after and I have a feeling with lowering springs might be causing some vibration in that area that is transferring back to the wheel. As for the hubs they had a lot of surface rust, I tried to clean them today with what I had but they still felt somewhat ruff after, probably causing the wheels to not sit fully flush but could be wrong. Going to order Koni Yellow Adjustable struts and see how much that helps and clean up the hubs better.

[Ownallday]

Came back to add onto something else that helped reduce the vibration. Finally replaced all 4 struts with Koni Yellow Adjustable struts. WOW! What a difference that made! I honestly think the struts I had in the car might've been the original ones from the 70s! However adding new struts reduced my vibration by about another 50%. So I'd say I only have about 15-25% of the vibration left in the steering wheel from before. Now I only feel vibration when going from approx 40mph to 60 mph but it's a lot less noticeable and doesn't really bother me at all anymore.

[Dave WM]

for me it was going back to steel rims and new tires. I never tried the new tires on the slotted alum mags, so it may have been just a defect in the old tires. I have the orig struts (the stock rebuildable ones) on the front and some non gas filled carts on the back. I have ZERO vibration at any speeds. My guess is the tires, I may go back to the slotted mags if I lose another wheel cover, I have thrown 2 now and its getting aggravating. 

[kully 560]

I had the same problem like you, and I did change ever thing from rack, to struts, to bushings, tie rods, and even springs. it turn out my drivers side floor board was week with some rot starting and since I replace the floor pan the car is perfect now!!!

[Ownallday]

1 hour ago, Dave WM said:

for me it was going back to steel rims and new tires. I never tried the new tires on the slotted alum mags, so it may have been just a defect in the old tires. I have the orig struts (the stock rebuildable ones) on the front and some non gas filled carts on the back. I have ZERO vibration at any speeds. My guess is the tires, I may go back to the slotted mags if I lose another wheel cover, I have thrown 2 now and its getting aggravating. 

I've been wanting to throw my wheels out of the question for a long time but I don't have any friends with wheels that would fit my car. I currently have gold Enkei wheels which you cannot find anywhere anymore and I really love how they look on my car so I didn't want to buy new wheels unless I know they are the problem. I finally have a friend who is getting some new rota wheels and a tire setup that would fit my car in about a month. Going to try his wheels see if that changes anything. I had a friend that had mags, should've got them off him as a spare set would've looked pretty sweet with my color.

1 hour ago, kully 560 said:

I had the same problem like you, and I did change ever thing from rack, to struts, to bushings, tie rods, and even springs. it turn out my drivers side floor board was week with some rot starting and since I replace the floor pan the car is perfect now!!!

I have not change the rack itself, the only thing I touched were the inner and outer tie rods rack wise and poly bushings. I want to suspect the possibility of the steering shaft U joint being bad but there are not any replacement joints aside from one that needs to be welded by the looks of it.. My driver side floor was actually rusted really bad a couple years ago, I had a new floor and rail added to the cars driver side. I might have to double check the torque on my tension rods as I have the Technotoytuning Tension rods. I also know that my Driveshaft has a bit of play but from what I see the 78 280z driveshaft u joints cannot be replaced so need to save up a little more money and purchase a new driveshaft and see what that does.

[kully 560]

I chased for years with the same problem.  I also did the Technototytunning tension rods and there front adjustable lower control arms . mine was more of speeds around 65mph was the worst. the only shake I get now is when the car sits to long [ like 1-2 months sitting ] then I will need to warm up the tires for 2-3 miles then it is perfect. the tires must get a flat spot after sitting for a while. as I found out any thing that shakes or has play will effect it. I spent several years chasing that problem, changing and replacing all those parts until 1 day I was under the car and saw that little bubble of under coating down under the drivers seat.  it was a 6" x6" rust starting and weaken the floor board. since I change that whole floor board things are perfect now. but like you ever part I changed was for the better and I can not tell you how many alignments and balancing jobs I had done . do not give up you will find it and then you will say $^!# that was it .

[Ownallday]

16 hours ago, kully 560 said:

I chased for years with the same problem.  I also did the Technototytunning tension rods and there front adjustable lower control arms . mine was more of speeds around 65mph was the worst. the only shake I get now is when the car sits to long [ like 1-2 months sitting ] then I will need to warm up the tires for 2-3 miles then it is perfect. the tires must get a flat spot after sitting for a while. as I found out any thing that shakes or has play will effect it. I spent several years chasing that problem, changing and replacing all those parts until 1 day I was under the car and saw that little bubble of under coating down under the drivers seat.  it was a 6" x6" rust starting and weaken the floor board. since I change that whole floor board things are perfect now. but like you ever part I changed was for the better and I can not tell you how many alignments and balancing jobs I had done . do not give up you will find it and then you will say $^!# that was it .

MMM, a lot of people told me they think my tires are bad but I actually drive the car pretty often so it's not sitting too long. I'll do some more testing as the weeks go by and replace the rest of the things that I have yet to in order to see what fixes it. Whats weird is hearing all these problems of rust in the floors causing shaking but when I had a hole in my floor board and frame rail I had zero shake from the steering wheel. I will 100% update what else fixes the shake on this post to help any future people who have similar problems but part of me believes the rest of the shake is potentially my driveshaft and axles even though the entire car doesn't have vibration. Gad you found your issue haha.

[w3wilkes]

Once upon a time on my old 73 240z I put Michelins on my car after I wore out the factory Toyo's and with them came a steering vibration at about 60+MPH. I tried rotating and rebalancing and nothing would correct the vibration. After putting up with it for a couple of years I replaced the Michelins with BF Goodrich Radial T/A's and low and behold the vibration was gone!

[chaseincats]

I had the same issue and discovered it was the wheels.  Both sets I had, had their lug nut holes wallowed out a bit and were somewhat ovular.  So even though the lug nuts were on there tight, the wheel could still move a millimeter or so in the lug nut hole creating the steering wheel vibration.  I did the same as you in replacing basically the whole front of the car and having the tires balanced multiple times until I tried other wheels. 

[Ownallday]

On 5/8/2022 at 9:27 AM, w3wilkes said:

Once upon a time on my old 73 240z I put Michelins on my car after I wore out the factory Toyo's and with them came a steering vibration at about 60+MPH. I tried rotating and rebalancing and nothing would correct the vibration. After putting up with it for a couple of years I replaced the Michelins with BF Goodrich Radial T/A's and low and behold the vibration was gone!

Very weird so our cars are prone to change drastically depending on the tires. Might have to swap out my tires see what changes. Currently running Hankook RS4 225/45R15. I always questioned if the sidewall was too little for this car. Might have to try Toyo R888 225/50R15 next as most people I know with Z cars run that setup. Glad yours was a simple fix that was found way later haha.

On 5/9/2022 at 3:01 PM, chaseincats said:

I had the same issue and discovered it was the wheels.  Both sets I had, had their lug nut holes wallowed out a bit and were somewhat ovular.  So even though the lug nuts were on there tight, the wheel could still move a millimeter or so in the lug nut hole creating the steering wheel vibration.  I did the same as you in replacing basically the whole front of the car and having the tires balanced multiple times until I tried other wheels. 

The wheels I have currently have lug holes that were apparently repaired. My friend ran them on his 240z before selling them to me and his car was perfectly fine and I also had another friend test fit my wheels on his Z and it was fine too. This was before I got my Hankook Tires.