Iron Cross Lugnuts

[mr_han_solo]

Hello,

I was wondering what the correct lug-nuts for the Iron cross wheel were:

I'm assuming that they look like this:



When I bough the car these are the lugs that were on there which are 240z lugnuts:


My question is, are the lug nuts I have on there safe? Now I haven't had any problems with them since I have been driving the car but I have been having a persistent vibration. I have been going through things on the checklist (rear end, new bushings, u-joints, etc.) in an attempt to narrow it down. I'm just wondering if these lugnuts could be the potential problem.

Thanks.

 

Edit: To clarify that the lugs that are on the wheels are 240z lugnuts.

Edited November 25, 2014 by mr_han_solo

[z240]

These wheels rely on the correct shank diameter to center them. They require the Nissan nuts or ones with the same OD.

Dealer has them, but last time I bought some they were $10 each or so!

 

If you get desparate I have a spare set of 8/10 looks wise that are totally usable. $3 each?

 

Maybe someone closer will chime in. I'm sure this was discussed before, in the context of finding locks with the right diameter, don't remember is anyone found an alternate source thought...

[Savage42]

Nissan only.  New or hit a wrecking yard that may have some wheels (factory aluminum) with those factory lug nuts.  The only option and DO NOT USE those other ones!!  Bad things will happen!!

Edited November 25, 2014 by Savage42

[beermanpete]

In addition to the diameter, check the length. It the shank is too long the nut will bottom out on the hub before the shoulder is tight against the wheel.

[z240]

Here ya go.

 

PN  40224-R4670

 

http://www.am-autoparts.com/Nissan/300ZX/lug-nuts/AM-538611754/678875.html

 

Dorman has a part number for them as well 611-241

Edited November 25, 2014 by z240

[mr_han_solo]

After looking at everyone's suggestions I dug around and found an extra alloy lug that I had and an extra lug that I have on my car now, which I assumed was the stock 240-280, steel rim lug-nuts. 

 

If you look at the lug on the right (the lugs that are on my car) you will see 1/2"-20. It looks like the previous owner put aftermarket non-metric lugs on the car! Now I haven't looked to see if they interchange, but I'm assuming they don't. I have went ahead and ordered a set of the correct alloy lugs, because the way I see it, driving with these lugs is outright dangerous.

 

For future reference I pulled out caliper and made the following measurements:

 

Alloy Wheel Lugs:

Shank Diameter/Width: .747
Shank Length: .647 Without washer.
.527 with washer

240-280z Steel Lugs Owner Installed 1/2-20 Lugs:

Shank Diameter/Width: .678
Shank Length: .776 without washer.
.656 with washer

 

If anyone could take the measurements off of the 240-280 Stock steel lugs I will add them.

 

Even if the 1/2-20 is interchangeable with the M12-25 the Shank diameter and length is different from what I need. Thanks everyone for the replies!

[z240]

while 20 TPI and 1.25mm threads are really close in pitch (0.05 and .04921 inches per thread), the 1/2" and 12mm diameter are not even close.  I'm betting those nuts don't spin on to M12x1.25 studs by hand. More likely the studs have been changed as well. I have seen discussions here and elsewhere of using 1/2x20 studs with similar knurl sizes.

 

Do not proceed until you ID the stud dimensions as well.  For example, can you spin that Nissan lug onto your studs? I'm betting not. However since 1/2x20 is larger, you could possibly put a 1/2x20 nut on a M12x1.25 stud and it might "seem" like it works, though very loosely.  Proceed with caution here until you get this sorted out.

Edited November 25, 2014 by z240

[mr_han_solo]

while 20 TPI and 1.25mm threads are really close in pitch (0.05 and .04921 inches per thread), the 1/2" and 12mm diameter are not even close.  I'm betting those nuts don't spin on to M12x1.25 studs by hand. More likely the studs have been changed as well. I have seen discussions here and elsewhere of using 1/2x20 studs with similar knurl sizes.

 

Do not proceed until you ID the stud dimensions as well.  For example, can you spin that Nissan lug onto your studs? I'm betting not. However since 1/2x20 is larger, you could possibly put a 1/2x20 nut on a M12x1.25 stud and it might "seem" like it works, though very loosely.  Proceed with caution here until you get this sorted out.

 

Oh I am, not even planning on driving it until the new lugs come in. After I posted this I went and checked the studs and they are indeed the stock studs. The alloy wheels are obviously later model wheels. When I got the car from a previous owner it only had 4 of the correct lugs. The remainder of the lugnuts are the 1/2x20, in face I found extra 1/2x20 lugs in the car after I bought it. In several cases I have put the lugs on the studs and actually stripped the threads on the lugs themselves. Until today I figured this was due to the age of the studs or the lugnuts. However, I now know it was because the nuts themselves were incorrect. It always explains why the previous owner kept extra lugs in the car too.