Genuine BMW 325i Differential

BMW 325i Differential Parts Questions & Answers

• Rear Axle Drive Differential
  33-10-7-591-014
  Q: How to remove and install a differential in a BMW 325i?

  A: This is a difficult procedure for the home mechanic, as it requires an engine lifting device and a transmission jack. Disconnect the negative battery cable. Block the rear wheels. Raise the front of the vehicle and securely support it on jackstands. Remove the fasteners, engine splash shield, and the shield below the radiator. Remove the cabin air filter housing. Remove the engine air filter housing. Open the hood to the most upright position and attach an engine lift or engine support assembly to lifting points on the engine. The engine only needs to be raised enough to remove the weight from the engine mounts. On the left side, disconnect the tie-rod end, tension strut, control arm, and the strut-to-steering knuckle pinch-bolt. Remove the driveaxles. Remove the bolts and the front subframe reinforcement panel, if equipped. Disconnect the vent hose from the differential case. Make match-marks on the front differential flange and the front of the driveshaft, as well as the rear of the driveshaft and the flange at the transfer case. Remove the bolts securing the driveshaft front yoke to the differential flange. Remove the bolts securing the driveshaft rear flange to the transfer case, and remove the driveshaft from the vehicle. Remove one subframe mounting bolt and purchase new bolts that are 2.5 inches longer. With a suitable support under the subframe, replace each of the subframe mounting bolts with the longer bolts. Lower the subframe two inches to access the differential-to-oil pan mounting bolts. Remove the differential from the vehicle. Installation is the reverse of removal, noting the following points: This is a good time to replace the driveaxle oil seals while the differential is out of the vehicle. Use a new O-ring between the oil pan and the differential. Use the original subframe bolts or new bolts of the same length as the original. Check and top-off the lubricant in the differential.
• Rear Axle Drive Differential
  33-10-7-566-179
  Q: How to remove and install a rear differential?

  A: New nuts for the driveshaft rear coupling and new bolts for the driveaxle retaining will be required during installation. Removal: Block the front wheels. Raise the rear of the vehicle and securely support it with jackstands. Remove both rear wheels. Use paint or a marking pen to make alignment marks between the driveshaft and the rear differential flange. Unscrew the bolts/nuts that secure the driveshaft to the rear differential and discard them; new ones must be used during installation. Remove the driveshaft. Disconnect the vent hose from the differential. On E-series chassis models, remove the driveaxles. On F-series chassis models, the driveaxles must be removed once the rear differential is partially lowered. Do not allow the driveshaft to hang under its own weight as the CV joint may be damaged. Discard the bolts; new ones should be used during installation. Remove the nuts/bolts and the heat shield panel from the left-hand end of the tension strut beneath the differential input-shaft flange. Move a floor jack and a block of wood into position and raise it so that it supports the weight of the differential. Making sure the differential is safely supported, loosen and remove the bolts securing the front of the unit to the subframe and the single bolt securing the rear of the differential to the subframe. Carefully lower the rear differential out of position and remove it from underneath the vehicle. Examine the differential mounts for signs of wear or damage and replace them if necessary. Installation: Raise the differential into position and engage it with the driveshaft rear joint, making sure the marks made prior to removal are correctly aligned. Insert the differential front mounting bolts, then the rear bolt. Tighten the front differential mounting bolts to the specified torque setting, followed by the rear bolt. Install the new driveshaft joint bolts/nuts and tighten them to the specified torque. Install the new driveshaft joint retaining bolts and plates and tighten them to the specified torque. Refill/top-off the rear differential with oil.