The following article gives detailed instructions on servicing the transfer case on a BMW E60 5 series xDrive (all wheel drive) car. Even though we have used a 2006 BMW 530xi to perform this service, this article can be applied to any E60/E61 5 series xDrive vehicle with minor modifications.
A BMW E60 transfer case service is recommended every fifth oil change or every 50,000 miles, whichever comes first.
The transfer case in your BMW xDrive (all wheel drive) vehicle is an electronically actuated set of gears that controls how much power is sent to the front and rear wheels. It is situated behind the vehicle’s transmission, approximately in the middle of the vehicle.
The BMW E60 transfer case is basically a third “middle” differential that redirects power from the transmission to the front and rear differentials. As power is fed into the transfer case from the transmission it is distributed to the front and rear differentials in a 40%/60% split, respectively. If the rear wheels start to lose traction, more power is directed to the front so the driver can remain in control of the vehicle.
The BMW E60 transfer case is not a maintenance free component. In fact it is recommended that the transfer case fluid is changed every fifth oil change (or every 50,000 miles). For those BMW owners that change their oil more frequently than every 10,000 miles, we recommend using the 50,000 mile rule for servicing your transfer case and not the oil service interval.
How to fill the transfer case with new fluid
The normal procedure for filling the BMW E60 transfer case with new fluid is unfortunately a very difficult process. The fill plug is located on the upper right side of the transfer case above its mounting bracket. In order to properly remove the fill plug, first the exhaust system must be lowered and the underlying heat shield removed. Next, the transfer case must be supported with a floor jack while its mounting bracket is taken off. Then everything must be put back together and torqued to the proper specifications to avoid future issues with the drivetrain.
Not only is removing the fill plug a complicated procedure for the seasoned technician working under a hydraulic lift, it is a nightmare for the home mechanic lying on their back underneath a car with very limited work space.
We have always been very adamant at the BMW Repair Guide in avoiding “shortcuts” when maintaining our vehicles unless following the normal procedure is not practical and a suitable alternative method exists. Attempting to disassemble the exhaust system and the transfer case mounting bracket to access its fill plug is not a practical solution for the home mechanic…there is an easier procedure that produces the same end result.
The BMW E60 transfer case can be easily refilled through the drain plug with an inexpensive fluid transfer pump and rubber stopper with a hole drilled in the middle of it. Refilling your transfer case through the drain plug is so simple, it turns a 3-4 hour repair into a procedure that can be done in about 45 minutes. There are no brackets that need to be removed…simply empty the old fluid and refill the case through drain hole. The following video shows how to do it. Please see our Tools and Supplies list below for a complete inventory of what you will need to perform the drain plug refill. In Section 2 of the repair we give detailed step by step instructions and video on how to perform the drain plug refill as well.
The BMW E60 transfer case uses a special xDrive DTF1 lubricant made specifically for your car. It is good practice to always replace the drain plug when servicing your transfer case. Never use any other type of lubricating fluid in your BMW E60 transfer case except Genuine BMW DTF1 lubricant. Other lubricants can damage the gears inside of the case.
1. Transfer case service kit (required) – This kit includes Genuine BMW DTF1 lubricating fluid and both fill and drain plugs (you won’t need the fill plug in this repair). We know the fluid is expensive, but never use any other brand in your E60 xDrive transfer case…it could damage it.
Transfer Case Service Kit – Genuine BMW83220397244
Part 1 – Tools and supplies for refilling the transfer case through the drain hole
Fluid transfer hand pump
Rubber stoppers – assorted sizes
7/16″ paddle bit
Part 2 – Other tools and supplies
Floor jack – low profile
14mm Hex Socket
14mm boxed end wrench
14mm crows foot socket
8mm nut driver
Screwdriver – phillips
Torque wrench – medium range
Plastic mixing cup
Draining the transfer case in your BMW E60 5 series is a relatively easy procedure. You will need to jack and support your vehicle on ramps or stands so you have enough room to get underneath the car. Remember…this is a messy job. We highly recommend performing this repair somewhere you don’t mind getting dirty.
- Jack and support your car at all four wheels using wheel ramps or stands. The BMW Repair Guide does not recommend using jack stands to support your vehicle unless the wheels need to be removed for the repair. For more information on jacking and supporting your vehicle, please see our article BMW Jacking and Supporting for Repairs and Maintenance.
- Remove the engine (front) belly pan. The belly pan is held in place on the BMW E60 with phillips head screws.
- Using an 8mm nut driver, remove the underfloor (rear) belly pan from the bottom of the car.
- Locate the transfer case. It is mounted to the rear of the transmission in approximately the center of the vehicle.
- Locate the drain plug located on the lower front of the transfer case.
- The drain plug requires a 14mm hex socket for removal. Unfortunately, there is not enough clearance between the transmission oil pan and the transfer case to get a standard 14mm hex socket into the plug (see image below). The BMW Repair Guide recommends an easy shortcut to solve this problem…cut the end off of a 14mm hex socket and use a 14mm boxed end wrench to remove the plug. With a little assistance from a rubber mallet (the plug is usually torqued very tight), it will quickly break free.
- Remove the plug and allow the transfer case to thoroughly drain into a large plastic cup. Do no use a drain pan to capture the old fluid…you may want to reuse the fluid to practice refiling the transfer case through the drain hole (we know this sounds confusing, so please see section 2 below for more information).
As discussed at the beginning of this article, we strongly feel that removing the exhaust and the mounting bracket to refill the transfer case is completely unnecessary. Refilling the transfer case through the drain hole is quick, easy, and the best option for the home mechanic. If this is your first time refilling the transfer case using this method, we strongly recommend doing a test run with the old fluid that was drained out in Section 1 – step 7 above. Once again, we encourage our readers to watch the following video and review the below steps before starting the procedure.
- Before refilling the BMW E60 transfer case, you will need to put together a simple device that will allow you to pump fresh fluid in without it spilling out. This can be easily accomplished with an inexpensive rubber stopper (1″x 3/4″ x 1″) and a hand transfer pump. By drilling a 7/16″ (11mm) hole in the center of the rubber stopper with a paddle bit, the transfer pump hose can be inserted securely into the transfer case without using the hard to access fill plug.
- The first step is to drill a hole in the center of a rubber stopper. The rubber stopper should have the following approximate dimensions: 1″ (top width) x 3/4″ (bottom width) x 1″ (total length).
- Using a 7/16″ (11mm) paddle bit, carefully drill a hole directly through the center of the rubber stopper. Try and keep the hole in the center of the stopper as best as you can.
- Insert the rubber stopper about half way into the transfer case drain hole. You want it slightly snug, but not too tight. If it is too tight you won’t be able to insert the transfer pump tubing in the next step.
- Cut off a 6″ piece of the tubing that comes with the transfer pump (it is easier to pump the fluid in with a shorter piece of tubing). Firmly insert the tubing into the rubber stopper.
- Attach the transfer pump to the tubing in the rubber stopper. Run another piece of tubing from the pump to a bottle of BMW DTF1 transfer case fluid (or if you are doing a test run…to the plastic cup of old fluid). If you have a helper available (like this fine gentleman in the image below), have them hold the bottle of transfer case fluid so it doesn’t tip over while you pump it.
- Using slow and deliberate strokes, pump the entire 1 liter container of fluid into the transfer case. We recommend pumping the entire bottle into the case because a portion will be lost when removing the rubber stopper and reinstalling the new drain plug.
- When the transfer case is full of fluid, remove the pump and tubing from the rubber stopper. Block the hole in the rubber stopper with your finger to keep fluid from escaping.
- In one quick movement, remove the rubber stopper from the drain hole and insert the drain plug. Put pressure on the drain plug with two fingers while slowly turning it clockwise until it is snug. You will lose some fluid during this procedure but don’t panic…since you pumped the entire 1 liter bottle in you have plenty to spare. Technically the transfer box is suitably filled with 1/2 liter of fluid, so unless you lose more than 50% of what you pumped in you are in good shape. Once again, if you are nervous about this step, do a trial run with the old fluid removed in Section 1.
- Using a torque wrench and a 14mm crows foot socket, torque the drain plug to 60 Nm (44 ft-lb).
- You can now reinstall the front and rear belly pans.