Genuine BMW 428i Transmission Assembly

BMW 428i Transmission Assembly Parts Questions & Experts Answers

• Exchange 6 Speed Gearbox
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  Q: How to remove and reinstall the Transmission Assembly for manual transmission on BMW 428i?

  A:

  Before detaching the battery, check the warnings for reconnecting batteries before isolate negative battery. Jack safety up the vehicle and remove the underbody splash shields and the complete exhaust system with heat shields. In order to remove the rear driveshaft from the output flange, support the center of the rear driveshaft and remove the center bearing support fasteners to disengage the flex-disc from the transfer case. Remove the harness connector from the back-up light switch on the transmission. Make sure the rear driveshaft does not hang unsupported or the CV joint can be damaged. Take off the two fasteners and the splash shield with the body ground strap from the body; then, detach the exhaust bracket holding the catalytic converter to the transmission. Position the transmission on a jack and secure it. Remove the mounting fasteners for the rear transmission support. The transmission mount can remain bolted unless the unit is being replaced. Remove the transfer case and disconnect the servomotor harness connectors for xDrive models. Slow down the transmission jack and allow the engine and transmission assembly to tilt backward slightly while avoiding contact at the rear of the engine. Detach the clutch slave cylinder from the side of the transmission, taking care not to disconnect the fluid hose. I always suspend the cylinder from the chassis with wire so it does not allow air into the hydraulic system. Unplug the reverse gear switch and if start/stop equipped connector at the neutral position sensor. Remove the shift console from the top of the transmission, and then, working from above the transmission, remove the selector rod by detaching the retaining circlip and removing it from the gearshift lever. In order to remove shift arms, begin by supporting the front of the engine with a jack stand or hydraulic jack and releasing the locking clips. Take off the Torx-head bolts holding the transmission in place (note where they go and the length of the bolts) and then remove the transmission by pulling it rearward until the input shaft clears the splines on the clutch disc, then lower it down (be careful not to damage the clutch pressure plate). Make sure the bellhousing alignment dowel sleeves are in their correct location and replace them if necessary. Check the clutch, clutch release bearing and flywheel for necessary repairs and check the seals of transmission. Reinstall the Transmission and xDrive transfer case if equipped and also transfer parts from the old transmission if a new transmission is installed. Clean the input shaft and clutch disc splines and lightly lubricate them before installation. To reinstall the transmission support, center the rear of the transmission in the driveshaft tunnel. Tighten the support bracket bolts. After tightening, reinstall the driveshaft using new self-locking nuts. Hold the bolts stationary while tightening to avoid damaging the flex-disc rubber. Make sure to refill the transmission before starting or towing.