E36 Diff Fluid
The Performing a Major Service articles on an E36 318I and 325I in the August, September and October ’96 issues of the Roundel are an excellent guide. The following is my experience replacing the final drive fluid with Redline 75 x 90 gear oil on my ’96 328is.
2- Quarts Redline 75 x 90 gear Oil: Imparts 1-800-325-9043 $8.00/Quart 1- Sta-Lube Fluid Oil Pump: NAPA # 4344 $4.99 1- Gallon Jug that accommodates the above pump (Windshield fluid jug $1.79 with fluid) 1- 14 mm Allen Wrench: NAPA Service tool # 67264 $6.49 1- 14 mm Standard Length 3/8 Drive Hex Socket (1 inch long): Sears # 43546 $1.99 2- Fill and Drain Plug Seal Rings: BMW # 07 11 9 963 355 $0.10/each
The article recommends using a 14 mm hex (Allen) head socket and a reassemble torque of 51.6 LB-ft. There is approximately 2 3/8 inches between the front of the spare tire well and the face of the differential fill plug on my 328is. I could not find a 14 mm hex (Allen) head socket that would accommodate this and my torque wrench. I tried NAPA, Sears, Snap-On and Imparts. Snap-On sells # FAM14E for $17.65 that is ~2 3/4 inches long. Imparts sells # 38514 for $14.00 that is 2 13/16 inches long. The Snap-On socket by itself measures 1 1/4 inches. The Impart socket by itself measures 1 3/4 inches. Shortening the Snap-On would result in an over all length of 1 5/8 inches which might work depending on your torque wrench size.
I decided to make my own. I cut off 7/8 inch from the NAPA 14 mm Allen wrenches long end. This leaves you with an Allen wrench that is still useable. Although useable as is with the Sears socket I decided to epoxy the cut off Allen piece to the Sears socket. Otherwise, you will definitely drop it into the drain pan. The over-all length of this one of a kind tool is 1 3/8 inches. This just makes it.
It was recently brought to my attention that the FACOM D107-14 is now available. Knowing this, there is no reason to make your own.
Make sure your vehicle is on a LEVEL surface. Unless you’re very large, there is no need to jack up the car to change the fluid. You can reach everything as is. Mark one of the plugs so you can return them to there original positions. Once you have drained the fluid, jack up the front of the vehicle and see how much more fluid comes out. Lower the front. Replace the drain plug using a new seal ring torqued to 51.6 LB-ft. Fill using the StaLube pump and jug till fluid runs out of the fill hole.
Replace the fill plug using a new seal ring and torque to 51.6 LB-ft. Before you forget, make a note of the date and mileage. The Sta-Lube pump, although inexpensive, works very well. No mess. The combination of it and the gallon jug results in a stable package. Buy one for the transmission to eliminate any cross contamination of fluids.