FYI Tech Tips: For Your Information is a column of tips and info for the benefit of Z owners
Manual transmission tips:
When driving, don't hold or rest your hand on the shifter of a manual transmissioned car. The weight or pressure pushes the shift forks against the slider and wears out those parts faster. It's best to use your arm rest not your shifter.
Since reverse isn't a syncrhonized gear like the forward gears are, going from neutral straight to reverse may occasionally grind or clunk. To avoid the "clunk" or grinding sound when going into reverse from neutral, first shift into a forward gear like either 5th or 3rd.
Toyota 4 piston caliper conversion:
If you have installed the Toyota 4 piston caliper conversion, make sure the spring that spreads the pads is installed on the bottom of the pads not the top. If installed on the top, the pads will grab the rotor and make a clicking sound as well as squeel. I've experienced this but moved the spring and all the problems were fixed.
Belt squeal from oil leak:
What happens on some 1990 300ZX models (specific build ranges below) is that the oil leaks out of the automatic belt tensioner (mimicking an engine oil leak) and the serpentine belt starts making a high-pitched squeal due to the lack of tension. Replace the tensioner (Part No. 13070-45V03) to solve both problems.
The affected models include those two-seaters built before VIN JN1RZ24A()LX015333 and production date 8/5/89, 2+2 models built before VIN JN1RZ26A()LX005317 and production date 8/9/89 and Turbos built before VIN JN1CZ24A()LX000960 and production date 8/31/89.