Differential Mount...

Z-Car Differential Mount:

This is an extra-strong front mount for the differential used in the 240Z, 260Z and 280Z.

The differential on Z-cars is subject to a tremendous amount of torque when accelerating. The stock differential mount is from the bottom, so the rubber pulls, rather than compresses, as the front of the differential moves up during acceleration. Even with a stock engine, Datsun realized that the movement needed to be limited, so installed a strap to prevent the differential from moving too far up. With added power, the differential mount in the stock car is overstressed. Also, when changing to a stronger differential (such as an R200), the factory limiting strap will no longer fit.

This differential mount is meant to contain differential movement by providing a strong, semi-rigid urethane stop at the top of the differential. It installs into the holes that were used by the factory limiting strap, and goes over the top front of the differential. The notch at the top of the mount is provided to allow for fuel line clearance.

The urethane stop bolts into the steel mount. You trim it to the correct length, so it is compressed about 1/8" by the differential top, via grinding, or cutting it with a hacksaw.

The mount is made of waterjet-cut steel, TIG welded, then powder-coated in gloss black. The urethane stop is included.

An alternate way to mount the differential is with a modified Energy Suspension urethane top-mount. This allows the differential to be mounted completely from the top, eliminating the need for the original stock bottom mount. This is a standard Energy Suspension part number 3-1108 that has been modified to have its hole spacing slotted to fit the mounting bolts on a Z-car differential. This mount is much stronger than the stock Z-car mount, being less pliable, and having an internal structure that prevents excessive movement. It is also under compression, rather than tension, when power is applied.

Price - $60 + $12 shipping for diff-mount ($28 for the modified top-mount)

Acknowledgements: This style differential mount is based on a design by Ron Tyler, and consequently is often called an R/T Mount or RT Mount. The mount offered here is similar to the original design, but also incorporates some improvements by "Datsun Dave."