78 280Z.

I finally got the car in a position today where I was able to drive it to see what other issues are present.

When the car starts to move there is a repetitive/rhythmic "clunk..clunk..clunk" that seems to be coming from the drivers side front wheel area. It almost sounds like if you are driving on a flat tire, but I just checked and aired the tires up, so I know thats not an issue, and I didn't notice any flat spots (the tires are probably insanely old though.)

I only took it around the block, and hit second gear maybe once or twice.

Hitting the brakes seems to quiet the noise up, but that's also because it gets more frequent with speed. 

I did change wheel bearings/races on both sides, as well as new calipers, pads,  and rotors on both sides as well.

 

Is it possible the spindle nut is too loose? I don't feel any vibration in the wheel when this is happening, but I feel that I can feel it mildly transferring through the car.  I'm particularly worried about road testing it more because of this issue, so if anyone has any ideas they can chime in with I'd greatly appreciate it.

It could be lots of things. My guess would be some suspension bolt not done up tight enough.

I took a video earlier tonight. It's hard to tell over the engine noise, but you can definitely hear that rhythmic "thump, thump, thump"  I swear it sounds like a flat tire or something, but my tires aren't flat or low on air, and they don't have any flat spots, either.

Edited February 27, 20241 yr by NocturnalEmber

Rusty or warped brake discs?

2 minutes ago, jonbill said:

Rusty or warped brake discs?

 

 Calipers, pads and rotors are all new I'm afraid. I just finished them today. Wheel hubs spun perfectly fine on both sides before and after I bolted everything up.

It definitely sounds like something is hitting every revolution of a wheel. 

Have you tried swapping that front left wheel to the rear?

42 minutes ago, jonbill said:

It definitely sounds like something is hitting every revolution of a wheel. 

Have you tried swapping that front left wheel to the rear?

 

That I have not, I took it around the block twice at a low speed to try and pinpoint where it was coming from then parked it for the night. 

Now that you mentioned the wheels though...something seems out of place..maybe you are onto something?

 

I had all the studs replaced on the front hubs when I did the wheel bearings, races etc, right?

On the drivers side, the lug studs stick out past the rim surface when you have the rim flush against the hub to put the lug nuts on. 

On the passengers side, they do not stick out past the wheel face.

I ordered the same studs, so those aren't different. Are those wheels different or keyed to the front or back on the 78's ?

Had a pretty competent machinist press the studs out and in, and he verified fitment before he pressed them in.

 

Edit: This might be unimportant, but I thought I'd mention it.

Here are the lugnuts I bought

https://www.rockauto.com/en/moreinfo.php?pk=1533170&cc=0&pt=7676&jsn=730&optionchoice=0-0-1-1

Dorman 611107.

On the drivers side with the lug nuts that stick out past the wheel face, they go on fine. On the passenger side, I can only get 2/4 on, because they won't line up. Maybe theres an issue with the lug nuts? (though when I got the car it only had 2/4 lug nuts, even on the old studs.) But it really is weird to me how the studs stick out past the wheel face on the drivers side rim, but not on the passenger side. The studs are the same, I don't know what could be causing that.

Edited February 27, 20241 yr by NocturnalEmber

I don't quite understand what you're describing, but it sounds wrong. It should be the same left and right.  I don't know what wheels you have, some fit different wheels front and back, but the standard is the same wheels front and back.

Just now, jonbill said:

I don't quite understand what you're describing, but it sounds wrong. It should be the same left and right.  I don't know what wheels you have, some fit different wheels front and back, but the standard is the same wheels front and back.

Trying to find a better way of saying it... 

 

If you put the rim against the hub like you're about to thread the lugnuts on: 

 

The drivers side front has studs that stick out past the lug holes.  The passenger side front, the studs are recessed inside the wheel.  

They are the same studs in each hub, I ordered a set of eight and thats what were pressed in, so it just seems weird that the studs on the drivers side would stick out further than the ones on the passengers side when they're the same studs.

Do Z's have different front and rear wheels? 

I took a photo of the driver and passenger side front wheels:

Driver side front:

Passengers side front:

 

You can see how the studs don't stick out past the surface of the rim on the passengers side, and I can't get it to line up with the other two lugs to get them on.

 

As for the drivers side, I think the lug nuts may also be an issue...The washer on two of them could be freely spun, even though the lug nuts are torqued down, I'm going to try replacing the new lug nuts on the drivers side with the old four lug nuts it had on it before and see if that stops the noise. For all I know the wheel isn't torqued down, and thats causing the noise.

The wheel isn't seated all the way against the hub face. Driveshafts would also be a suspect for clunky noises

9 minutes ago, Patcon said:

The wheel isn't seated all the way against the hub face. Driveshafts would also be a suspect for clunky noises

Or the new studs weren't fully seated when installed and still need to be drawn out with the nut. There is a reason all new wheels are hub concentric these days, the old stud concentric wheels like yours were problematic.

7 hours ago, NocturnalEmber said:

The washer on two of them could be freely spun, even though the lug nuts are torqued down, I'm going to try replacing the new lug nuts on the drivers side with the old four lug nuts it had on it before and see if that stops the noise. For all I know the wheel isn't torqued down, and thats causing the noise.

You've been lucky.  Your wheel is probably wobbling and that can cause the nuts to loosen.  Once they get loose they spin off pretty fast.  I lost two lug nuts on about a 1/2 mile drive because I forgot to torque them down after putting a wheel back on.  The remaining two were trying to be free also.  

Stick the lug nut in the holes before installing the wheels.  If the nut sticks all the way through the hole it's too long.

On 2/27/2024 at 1:46 PM, Zed Head said:

You've been lucky.  Your wheel is probably wobbling and that can cause the nuts to loosen.  Once they get loose they spin off pretty fast.  I lost two lug nuts on about a 1/2 mile drive because I forgot to torque them down after putting a wheel back on.  The remaining two were trying to be free also.  

Stick the lug nut in the holes before installing the wheels.  If the nut sticks all the way through the hole it's too long.

 

Okay, so! I changed out the lugnuts on the drivers side, sound is gone. Thanks for posting that drawing, that helped a lot actually in determining if the lugs were the right size or not. 

 

However, I still have an issue:

I can not for the life of me get all four lugnuts on the passengers side front wheel on, it's not happening.

I think the machinist bent the studs when he put them in. I did take pictures to the best of my ability, but I'm not an expert to tell if they are bent.  Can someone with a better eye for these judge for me? I tried to get a picture from the front, left, and right.

Something to note: The studs on the drivers side stick out past the holes in the rim, they do not stick out past the holes on the passengers side. This is very odd.

I bought eight new studs of the same kind and had the machinist press out all of the old ones on the front hubs and press in the new ones.

Unless he mixed up the studs (or rock auto send me exactly four of the wrong length) these should all be the same studs, so why would one side stick out past the stud holes on the driver's side, but not on the passengers side?  I guess the length isn't super important so long as I can get the studs to go in right, but why would they stick out longer  on one rim if they're the same length studs? (unless these rims are different on the back versus the front, I believe they are factory rims? The picture after the stud photos shows the passengers side front rim.

The lugs will thread onto the studs no problem without the rim being on the hub, so I know the threads aren't damaged, but you absolutely cannot get all four on there, the studs aren't in the holes centered.  From what I can tell, they are pressed in all the way on both hubs.

 

If anyone could help me make sense of this..I'd really appreciate it.

Edited February 29, 20241 yr by NocturnalEmber