Transmission Rebuild
As part of a comprehensive drivetrain refresh, I rebuilt the FS5W71B five-speed transmission from my 1982 Datsun 280ZX to resolve long-standing issues with gear engagement and drivetrain oil leaks. The project involved a complete disassembly and inspection of internal components, diagnosis of worn synchros and bearings, and replacement of critical gaskets and seals. Working from the factory service manual and supplementing with field-tested advice, I restored the transmission to OEM spec and improved drivetrain performance and reliability. The rebuilt unit was paired with a new clutch and pilot bearing, culminating in smoother gear transitions, reduced drivetrain lash, and the elimination of prior fluid leaks.
The rebuild centered on the FS5W71B gearbox, requiring careful extraction of the transmission assembly, teardown of the front and rear cases, and removal of the countershaft, mainshaft, and shift forks. Using a combination of factory tools and improvised methods—including a bearing puller, feeler gauges, snap ring pliers, and a magnetic pickup—I documented wear patterns on synchro rings and inspected tolerance on bearing clearances and gear faces. After diagnosing oil contamination on the clutch friction surface and identifying excessive shaft play, I resealed the oil pump, installed a new rear main seal, and restacked the mainshaft cluster with OEM replacement parts. Timing and ignition issues were addressed in parallel, including correction of an improperly indexed distributor shaft. The finished system starts cleanly, holds timing, and performs confidently under load.
