Differential & Transfer oil changing is important and essential maintenance service for your car.But usually,both of them are one of the most-overlooked tasks,because the differential and transfer are at the rear or under the car.However, if lubrication in the differential or transfer fails,so in this article i will share the guide on How to Change Diffs And Transfer Case Fluid/Oil for BMW X1 xDrive.
Tools what you need ?
*BMW OEM Transfer Case Fluid: $84.12 after taxes
*Fill/Drain Plugs x 2: $31.50 after taxes
*Redline 75W90 x 2: $49 after taxes
*Lift/shop/tool usage: Case of Beer!
*Fluid pump (Syringe Type) – similar to picture below, 18mm wrench and socket, 14mm Allen bit,16 mm socket, ratcheting wrench (see picture similar to it, but from Craftsman), Torque Wrench
*Lift: I used my friend’s lift. It can be possible to do this at home, if the car is jacked up
enough and kept perfectly level. Reasons why I chose the lift was to make sure that the
drain plugs are not angled as to restrict the fluid from coming out and also not over-filled at
the same time when filling up and unobstructed access with safety.
Fluids Used:
- Differentials–front and rear–Redline 75w90–2 Quarts
- Transfer Case: BMW Original Fluid–DTF1–Picture below BMW Part # 83222409710 -1 quart
Replaced two drain plugs on the Transfer Case, reused the ones on front and rear diff, as they were in really good condition.
Front Differential Fluid Change:
Started with the front differential–removed the bottom plate to get to the differential. 6
bolts–16mm. Picture of plate below:
Front diff and drain plug visible as in this picture:
Fill plug is here:
To access the fill plug, we removed the side splash covers adjacent to the CV axle. After removing the fill plug, we then removed the drain plug, as in picture below:
Once removed, the oil drains out as in picture below:
We measured it using the marked jug container seen in the picture. The amount of oil that
came out was 650 ml (0.68 quart). Once everything was drained, we closed up the drain plug.
Color was darker than the fresh fluid, about 40% darker.
With drain plug closed, we filled in the Redline 75w90 using a syringe pump until the oil started
coming out of the diff in a steady flow. Once the flow stopped, and the dripping became drop
after drop, we closed off the fill plug.
Torque values for 11AZ Drain and Fill Plugs is 60NM.
Transfer Case Fluid Change:
Place drain pan under your transfer case and remove 14mm Allen fluid drain plug.
Allow the fluid to drain completely. Once drained, reinstall the drain plug and tighten it.
The transfer case mount brace has to be removed to fill the transfer case as per other
instructions, however, we kind of loosened the brace without removing it to access the fill hole.
The large transverse bolt would not come out of the cross brace as the exhaust pipe was
blocking it. Quite cramped up there even with a loose brace. We were able to get to the fill plug
using a bi-directional ratcheting wrench and 14 mm bit.
We loaded the wrench from under after (Red Arrow) inserting the bit through the top left
(Green Arrow). Sorry, didn’t get a good picture of it as I had oil all over my hands. I’m using the
picture from Pelican Parts to show the specific locations.
We filled the fluid until it was coming out in a very thin stream for a few seconds. This stuff
from BMW is extremely expensive for a quart, so be careful and fill slowly. We reversed the
steps as above and torqued it to 60NM again, this time using the 14mm bit, ratcheting wrench
connected to the torque wrench. It’s a little bit unorthodox but beats removing a bunch of
parts. If I have to do it again, I would drop the brace and the heatshields etc.
Total quantity emptied was approximately 400 ml (.42 Quart)
Total quantity filled approximately 500 ml (.52 Quart)
Picture of the quality of oil that came out below. It was dark coffee colored and looked like
burnt.
Rear Differential Fluid Change:
The rear differential only has one plug–for both fill and drain. You need to use a pump to get
the fluid out and in. Plug location is below, facing away from the rear of the vehicle:
Better shot of the fill/drain plug:
We used the pump to pull as much as we can, and when we were done, we had about 700 ml
(0.73 quart) come out. The rear diff fluid was almost black but didn’t smell bad:
No metal particles found either.
We then filled the rear diff using the pump:
The fill took the entire 946 ml (1 Quart). Reinstalled the plug and torqued it to 60NM.