Blown Up Front Diff

[cn90]

Get a low mileage front diff.

I helped a friend replaced the front diff in his 2004 X3 E83 3 yrs ago (in 2022) and wrote it up in the link below.

Should be almost identical for E53 X5...

DIY: 2004 BMW X3 Front Diff Replacement @165K miles

https://www.bimmerfest.com/threads/d...miles.1436496/

[Peezen]

Thanks everyone! I have ordered a replacement part and the seals and little metal sleeve and guide are available on rockauto.

I also already have m10 studs from a different job so I’ll use that idea as well! I’ll post a picture of the blown out diff once I pull it.


Gotta get on this before winter arrives!


Is there anything else that needs doing as part of this job that needs parts in advance?

[cn90]

- The place I obtained the front diff (for E83 X3) was LKQonline
bc they tag every part with VIN and proved with odometer reading.

This way you know for sure the age/mileage from the part.

This not a job you want to do again.

All the relevant tips are in the DIY (for X3) that I posted above.

Idk what you ordered from Rock Auto, but for this job, I use only BMW parts...

[Effduration]

Originally Posted by Peezen

Thanks everyone! I have ordered a replacement part and the seals and little metal sleeve and guide are available on rockauto.
.................
Is there anything else that needs doing as part of this job that needs parts in advance?

How is your oil pan gasket?? Seems like a good time to replace it.

Maybe engine mounts also? But think about that carefully. On my '05 3.0, I am replacing my front subframe, and live in a rusty climate. I snapped 3/4 of the bolts holding the engine mounts in. If I wasn't replacing both the subframe and engine mounts and bolts, I would be in a world of suck....

[Peezen]

I just did an oil change and the pan gasket seems to be fine. I have disconnected the engine mounts and have the engine hoist in place but it does not seem to be lifting the engine off the mounts. It’s either super heavy or there is another contact point.

I’d only be ordering seals but rock auto isn’t necessarily the choice. They only have the one seal.

From the Bentley it looks like I am supposed to disconnect the steering before lowering the subframe, but I do know that sometimes the Bentley has more steps than are required. I think the X3 has more room at the bottom of the engine, I don’t see a way of getting the diff out without dropping it a bit, but I’ll have a better idea once it’s out. The top left bolt is hidden behind the steering arm and a couple of power steering fluid pipes. Not sure how I will get to that one yet.


There is a pretty big hole blown out of the front of the diff…. Wild. I don’t remember hearing anything or feeling anything sudden while driving.

[Peezen]

Not much rust here, but I’ll have a look at the bolts on the sub frame. From the Bentley it looks like the only support the front section with wood and floor jack. I image that means that they only loosen the rear bolts.

[cn90]

The DIY I posted above was for X3 M54 setup.

Yours is V8, so it is a bit different...

[Peezen]

You can get to the engine mount nuts from the top with a long extension, which was nice and easy.

The engine bay hoist works perfect situated a little forward in line with the front engine loop. Easy to lift the engine a few inches.


Take both axles out. I only took the steering ball joint out, which was pretty easy with a few taps from a sledge. For the other control arms I just undid the bolts at the subframe instead of trying to mess with the ball joint ends at the knuckle. Again pretty easy. The entire thing is pretty heavy with the axle and control arms attached, so for the driver side be ready to give some effort to pull it out and rest on the ground.

The passenger side was detached in the same way, but instead of pulling it completely out, I just pulled it away enough for the axle shaft to clear the front differential and then supported it with a jack stand an some wood against the strut tower.

I undid the two bolts holding the steering rack, and the six subframe bolts and was able to drop the subframe a substantial amount, supported with a longer piece of 2x4 spanning across the two sides of the subframe, with a floor jack. At that point the diff was begging to come out and just needed some wiggling and side movement of the subframe.


It’s a time consuming job due to the amount of things that need unbolting, but easy enough skill-wise.

We’ll see how the reassembly goes. I have attached some pics below.