Cuda's Cars, v2.0

[CudaMan]

OBD1 ftw?

Top nut (22mm) on the right front coilover was the clunk. Seems to be gone now after tightening it up. Good news, that. Means I didn't have to put the car in the air to hunt for a problem (ask me how long it takes to get the front on jack stands, as low as the car is now...).

If it works loose again I'll remove the nut and apply a bit of blue loctite. I used my impact wrench for the final torque - though it's a bit down on battery power so not at full strength.

[thesameguy]

Supa! Those are the nice fixes!

You should invest in a 2x6! They are great to drive onto to make getting a jack under a lowered car easier. Stick a 1' board under each wheel, or stack a couple of them like stairs to add a little more height. Like shitty, cheap, Rhino Ramps. I gotta use that setup with the SPG, or I end up using two jacks - a tiny one to get some height under the car so I can fit the large one. A few pieces of wood solves that issue, saves time.

[CudaMan]

Oh yes, I have to drive up on 2x4s, and even then it's a challenge. Stacking a second 2x4 under each front wheel helps.

[Godson]

I jack one side of the M3 up, place 4x4 under tire, then jack from front subframe.

[CudaMan]

New wheels and tires and lug nuts mounted. 5mm spacers up front. I seem to have only about 6 turns of thread engagement up front. Not sure if that's enough - I think I once heard that 4 turns is enough for full strength of a bolt, but what about a stud with the engagement at the outer end (wheel + spacer means there's a fair bit of stud length doing nothing)?

[thesameguy]

There are lots of rules of thumb when it comes to thread engagement, and really you can't know anything until you know about the materials and dimensions involved. The rule I've always used for wheel hardware is engagement should equal the diameter of the stud or bolt... so an M12 wheel stud needs 12mm of thread engagement... that's assuming you have steel wheel hardware and not aluminum, in which case you need double that. That's minimum - which isn't good enough for many sanctioning bodies, which generally have rules about exposed threads - eg, at least two threads fully exposed past the nut.

FWIW, I ran the XR4Ti for many years with five full turns on the studs and it made me nervous - it should have been about eight (M12x1.5). Nothing bad ever happened, and when I finally switched to longer wheel studs there was no sign of stress or damage to the old studs or nuts. But, that was for street use. I didn't track that car until I had more engagement.

[thesameguy]

Also, them wheels is ACE!

[CudaMan]

Threads exposed past the nut? But my nuts are huge! [Muteki SR48]

At 12x1.25, if my math is right that means 9.6 turns of engagement. Seems like a lot!

I wonder who makes quality extended studs besides ARP ($$$). Sometimes OEMs have options - I think my MR2T has front studs from a Land Cruiser or something. I'll look up how difficult it would be to remove/install studs with basic hand tools.

[Godson]

just shell out for the ARPs and be done with it.



That's what I did anyways.

[thesameguy]

Go to Dorman's website and look up replacement wheel studs for your car. That will give you the geometry. Then you can search for other cars with similar but longer wheel studs. I gotta believe someone on some forum has done this before, so you may do fine just googling "300zx longer wheel studs."

It's generally not too bad to swap wheel studs, but the gotcha is whether there is sufficient space behind the hub to get the old ones out or the new ones in. A good socket that will just slip over the back and a big c-clamp will do it, and sometimes a quick rap with a heavy (sledge) hammer is enough. Just don't beat on it and damage the hub or wheel bearings. It's helpful to hose things down in PB Blaster long before starting, and judicious use of Freeze Off during the process will help. Given the Z's RWDedness it may be painless to pull the front hubs off entirely and use a press to get the old ones out. That's what I did on the Fiero and XR. You can probably flip a local shop $20 to do it for you. Usually just a big beefy nut.

Installation can be done with a sacrificial lug nut and some heavy duty M12 washers, or there is a $25 Lisle tool which works awesome. Happy to mail mine to you if you like - I won't be installing more wheel studs for a while. You might check O'Reilly's etc, as they may have stud removal/installer kits available for rent.