Hints for changing Front and Rear Differential Fluids on a 2006 X3

While I had the my newly purchased 2006 X3 on a lift at the local tire repair shop I was able to walk under the car and inspect everything. The shop owner is a friend and they let me do a little work of my own every now and again while it is on the lift.

The car was ready for its Inspection II Servicing (61K miles). I went out a spent @ $65 for parts and tools to do the rear differential.

Purchased:
(2) Qts of Royal Purple 75-90W @ $20/QT at Advanced Auto
(1) Oil pump (the kind used to change lower gear oil for boats) @ $5 at Wally World
(1) short 14mm hex head socket @ $10
A pair of cheap latex gloves

Tools needed:
14 mm hex head socket
14 mm open-end wrench
9" 3/8" or 1/2" socket extender
3/8" or 1/2" ratchet
3/8" or 1/2" breaker bar
15 or 16mm socket for the stiffiner pan (front differential)
14 mm hex head socket insert (the shorter the better)
Shop rags
Oil Drain Pan

SPECIALTY TOOL NEEDED: FIND THIS ONE AND SAVE A TON OF TIME
(1) short stubby @1-1.5" 14mm hex head stud (14mm socket with removable stud). or cut 1.5" off a 14mm allen wrench

Front Differential
Remove both push pins on plastic radiator shield
Remove the front bolts on the stiffiner pan with 15 or 16mm socket - I am 99% sure it was the 16mm... Check first. The pan bolts are on tight so I had to use a breaker bar. (Actually used a 1/2 inch socket set and long breaker bar, but I have more tools than most folks, I think 3/8 inch bar will work fine, just will take more muscle).
Remove the bolts on the rear of the stiffiner pan
Remove the pan
Using a 14mm hex head socket with the 9" extender go over the frame to get to the top plug (This was done through the driver's side wheel well). I found that the plugs did not need a breaker bar to get them loose. They were tight but not too tight that it would require a breaker bar. Loosen and remove top plug.
Using the same hex head socket remove the lower plug and drain. NOTE: The Differentials and Transfer Case all appear to have drain plugs so there was not any need to use a pump to remove the fluids.
Let it drain for @ 5 minutes and wipe plug clean and replace the drain plug...The plugs have o-rings on them. Check to see their condition, if questionable replace.
Using the hand pump, place tube in differential and pump until fluid starts dripping out. It will take most of the quart bottle to fill the front differential.
Replace the upper fill plug and tighten it back. I did not have torque specifications, but tightened to @ what it took to remove the plugs.
Wipe exessive fluid from differential and replace both the stiffiner pan and push pins.
There will be @ 4 ounces of Royal Purple fluid remaining in the bottle...SAVE and use in the rear differntial.
FRONT DIFFERENTIAL JOB DONE.

Rear Differential [This is the tricky one}
NOTE: It takes a very short 14mm hex head socket to remove the fill plug on the rear of the vehicle. The rear tire and carrier sit too close to the fill plug to remove it without either lowering and removing the spare OR ACQUIRING A SHORT 14mm hex head. I was able to find one in the tool box of one of the mechanics. Actually, it was a 3/8 inch 14mm hex head socket that I could remove the 14mm hex head stud from by loosening the allen screw that holds the 14mm stud in place on the socket.

In essence what you need is about a 1-1.5" 14mm hex head stud that will fit in the plug.
You can then loosen the plug using a 14mm open-end wrench that fits the stud. Then remove the filler plug by hand because clearance tolerance between the differential and wheel carrier will not allow you to remove the plug otherwise.
Remove the drain plug with the 14mm hex head socket and ratchet
Drain for @ 5 minutes then replace the lower plug and tighten
Fill using fluid pump fill the rear differential with fluid. until fluid starts dripping from the filler hole. NOTE: It took about 1 Qt. and the remainder of the front fluid to fill the rear.
Replace the filler plug by hand and tighten using the short 14mm stud and open-end wrench. (It is a tight fit but can be done!!!)



Time taken to replace fluid in both front and rear differentials @ 1 hour.
Cost @ $55
Estimated time saved without having to remove the spare tire and carrier @ 1 hour.
Estimated money saved @ $200 -$250
Skill level needed (based on one-easy and 10-difficult) @ #4

If I would have had the expensive BMW Transfer case fluid it probably would have taken me @ 20 minutes to change the transfer case fluids because access to the transfer case fill/drain plugs are very accessible.

Sorry, no pictures as I was not wanting to tie up the shop and keep the mechanic from making $$$. I did all this while they were mounting and balancing new tires on the X3.

Good luck.

I could not find a short enough hex for the rear so I had to remove the tire holder- it was only about an extra 15 minutes, when you take out the tire and the 3 bolts at the hinged part of the tire holder you can rotate the complete holder out of the way without totally removing it-

Would love to see some pictures of these fluid changes in action as I'm getting near the point of needing these done as well.

Anybody have pics or know where some can be found?

Ditto that reed75. xfer case is obvious; front/rear diff is a little hard for me to visualize.

Does the 06 x3 3.0 require the LSD additave. And royal purple 75-90 is acceptable?

Originally Posted by AU99Z3MCoupe

While I had the my newly purchased 2006 X3 on a lift at the local tire repair shop I was able to walk under the car and inspect everything. The shop owner is a friend and they let me do a little work of my own every now and again while it is on the lift.

The car was ready for its Inspection II Servicing (61K miles). I went out a spent @ $65 for parts and tools to do the rear differential.

Purchased:
(2) Qts of Royal Purple 75-90W @ $20/QT at Advanced Auto
(1) Oil pump (the kind used to change lower gear oil for boats) @ $5 at Wally World
(1) short 14mm hex head socket @ $10
A pair of cheap latex gloves

Tools needed:
14 mm hex head socket
14 mm open-end wrench
9" 3/8" or 1/2" socket extender
3/8" or 1/2" ratchet
3/8" or 1/2" breaker bar
15 or 16mm socket for the stiffiner pan (front differential)
14 mm hex head socket insert (the shorter the better)
Shop rags
Oil Drain Pan

SPECIALTY TOOL NEEDED: FIND THIS ONE AND SAVE A TON OF TIME
(1) short stubby @1-1.5" 14mm hex head stud (14mm socket with removable stud). or cut 1.5" off a 14mm allen wrench

Front Differential
Remove both push pins on plastic radiator shield
Remove the front bolts on the stiffiner pan with 15 or 16mm socket - I am 99% sure it was the 16mm... Check first. The pan bolts are on tight so I had to use a breaker bar. (Actually used a 1/2 inch socket set and long breaker bar, but I have more tools than most folks, I think 3/8 inch bar will work fine, just will take more muscle).
Remove the bolts on the rear of the stiffiner pan
Remove the pan
Using a 14mm hex head socket with the 9" extender go over the frame to get to the top plug (This was done through the driver's side wheel well). I found that the plugs did not need a breaker bar to get them loose. They were tight but not too tight that it would require a breaker bar. Loosen and remove top plug.
Using the same hex head socket remove the lower plug and drain. NOTE: The Differentials and Transfer Case all appear to have drain plugs so there was not any need to use a pump to remove the fluids.
Let it drain for @ 5 minutes and wipe plug clean and replace the drain plug...The plugs have o-rings on them. Check to see their condition, if questionable replace.
Using the hand pump, place tube in differential and pump until fluid starts dripping out. It will take most of the quart bottle to fill the front differential.
Replace the upper fill plug and tighten it back. I did not have torque specifications, but tightened to @ what it took to remove the plugs.
Wipe exessive fluid from differential and replace both the stiffiner pan and push pins.
There will be @ 4 ounces of Royal Purple fluid remaining in the bottle...SAVE and use in the rear differntial.
FRONT DIFFERENTIAL JOB DONE.

Rear Differential [This is the tricky one}
NOTE: It takes a very short 14mm hex head socket to remove the fill plug on the rear of the vehicle. The rear tire and carrier sit too close to the fill plug to remove it without either lowering and removing the spare OR ACQUIRING A SHORT 14mm hex head. I was able to find one in the tool box of one of the mechanics. Actually, it was a 3/8 inch 14mm hex head socket that I could remove the 14mm hex head stud from by loosening the allen screw that holds the 14mm stud in place on the socket.

In essence what you need is about a 1-1.5" 14mm hex head stud that will fit in the plug.
You can then loosen the plug using a 14mm open-end wrench that fits the stud. Then remove the filler plug by hand because clearance tolerance between the differential and wheel carrier will not allow you to remove the plug otherwise.
Remove the drain plug with the 14mm hex head socket and ratchet
Drain for @ 5 minutes then replace the lower plug and tighten
Fill using fluid pump fill the rear differential with fluid. until fluid starts dripping from the filler hole. NOTE: It took about 1 Qt. and the remainder of the front fluid to fill the rear.
Replace the filler plug by hand and tighten using the short 14mm stud and open-end wrench. (It is a tight fit but can be done!!!)



Time taken to replace fluid in both front and rear differentials @ 1 hour.
Cost @ $55
Estimated time saved without having to remove the spare tire and carrier @ 1 hour.
Estimated money saved @ $200 -$250
Skill level needed (based on one-easy and 10-difficult) @ #4

If I would have had the expensive BMW Transfer case fluid it probably would have taken me @ 20 minutes to change the transfer case fluids because access to the transfer case fill/drain plugs are very accessible.

Sorry, no pictures as I was not wanting to tie up the shop and keep the mechanic from making $$$. I did all this while they were mounting and balancing new tires on the X3.

Good luck.

Thank you, This information will save me lots of time and frustration.

Thank you, this information will save me time and frustration.

I can confirm that the metal pan you need to remove is 4 x 16MM bolts for the front. I just did this today. I wound up removing the whole plastic front underbody shield because I couldn't figure out how to take out the two pushpins attaching the plastic to the metal pan. There were a bunch of 8mm bolt/screws.

I used Redline 75-90W, but like you, did not use the whole quart. In fact, I would estimate I probably only used .7 quarts as there was a lot left when the oil started flowing out of the drain hole. Tell me I shouldn't be concerned?

Also, worth mentioning that I did not have to jack up the car, I just crawled underneath to do all the work.

Someone call me crazy or show me otherwise, but I swear when I look at my Front and rear diffs on my 2007, as well as on the ETKA diagrams, I only see one plug. That requires the old fluid be sucked out, then the new pumped in.

Your not crazy. My new front diff only has a fill plug. Rear diff has a drain and fill plug.

First, those pushpins on the front plastic cover are tricky. They have two parts, a center pin and a threaded outer sheath. First pry down the center pin a little with a flat head screw driver, then use a set of needle-nosed pliers to get some leverage to pry/pull them out. The threaded outer sheath will remain in place. To get the sheaths out, I stuck my hand above the plate, and pushed them down and out from the top. Squeeze the top of them with your fingers, because they are split, and when you squeeze them and push down they pop right out.

Regarding the fluid, I ordered two bottles of Liqui-Moly SAE 75W-140 Synthetic oil, at $23 a bottle, thinking that would be enough for both differentials. BEWARE - this comes in 500ml bottles, so you need four bottles to do both differentials. I ended up buying a quart of Mobil 1 LS 75W-140 Synthetic locally and used that in the rear differential, and the Liqui-Moly in the front.

The Liqui-Moly bottles have a hose that pulls out, so you could use these to fill the rear (but not the front) differential without a pump. NO PUMP will fit on the top of the Liqui-Moly bottle. So if you want to use it in your front differential, you'll either have to pry out the integrated hose assembly and use a separate hand pump, or pour it into a standard hypoid gear oil bottle and use the pump mentioned in the first post.