Hi All,
Trying to correct the vibration feedback in the Z's steering wheel is one of those problems you can chase down a rabbit trail and add additional dollars redoing services, unless you find the correct service / shop.
Drove the Z to Solvang, CA this past weekend for the Datsun Roadster Classic (they include Z in the show), 340 mile round trip drive and the steering wheel vibration at 60+ drove me crazy the entire 300 + mile drive. Below 60 MPH puts you in the slow lane/ truck lane on the highway's which is also the roughest lane on the highway which compounded the issue.
Took the Z to Nate Jones Tire in Signal Hill CA today. Wow, what an eye opener. Nate is an 80 years old, racer, builder and great resource. The service included truing the wheel (rim and tire) on the car.
Frist tire pressure, Nate knew the Z's stock suspension was designed with a tire pressure rated at 28lbs max. I was running 36lbs on 205. Tires have too pressure for the suppression. He knocked the fronts down to 26 and rears to 28. Suggested with the mass of the tire, could run as low as 24 in the fronts and 26 in the rears for (dry) highway travel, track add 4lbs front and back.
Next removed and rotated all tires with the valve steam to line up over a stud location. This became the static mounting location for the wheel, on and off, must mount in this location ,no future rotation. until the tire is shot
Jacked the front up and rolled a custom machine (looked like a lawnmower base) and attached to front tire. Hit the inside edge of the rim lip with a small grinding blade, knocked down any shimmy / wobble imperfection in the wheel (rim) during rotation.
Next trued the tires. We all let our cars sit for extended periods, this can create flat spots that will cure it self over time and miles. The equipment shaved grooves in the tread (top not side wall) and trued or rounded the tire.
Next rolled another unit to the tire and applied a counter weight ring on the outside of the rim. Than rotated the tire and wheel (on the car) at high rpm. With a several feelers hitting the rim edge inside and outside and a strobe light he picked up the balance position of the wheel and tire at high RPM. Applied weights.
The end result, vibration in steering wheel gone, vibration in car gone and a quieter cockpit. Great experience with I fear is dying expertise.