The crankshaft can only be removed after the engine has been taken out of the vehicle, assuming that the flywheel or driveplate, crankshaft balancer/vibration damper, timing chain, timing gear, oil pan, oil pump, and piston/connecting rod assemblies have already been detached. For Quad-4 engines, the rear main oil seal housing must be unbolted and separated from the block prior to crankshaft removal. Before proceeding, check the endplay by mounting a dial indicator with the stem aligned with the crankshaft and touching one of the crank throws. Push the crankshaft to the rear and zero the dial indicator, then pry it to the front and check the reading; the movement indicates the endplay. If it exceeds the specified limit, inspect the crankshaft thrust surfaces for wear, and if none is found, new main bearings may resolve the issue. If a dial indicator is unavailable, feeler gauges can be used by prying the crankshaft to the front and measuring the clearance between it and the thrust main bearing. Ensure the main bearing caps are marked for their locations, numbered consecutively from front to rear, and if not, mark them appropriately. Loosen the main bearing cap bolts gradually until they can be removed by hand, noting any stud bolts for proper reinstallation. Gently tap the caps with a soft-face hammer to separate them from the engine block, using the bolts as levers if necessary, and take care not to drop the bearing inserts. Finally, lift the crankshaft out of the engine, ideally with assistance due to its weight, and with the bearing inserts in place, return the caps to their original positions on the engine block and tighten the bolts finger tight.