Front diff replacement questions on an e70 x5 lci 35i

[GearHead335i]

Hey guys, so I’ve confirmed that my buddy needs to replace his front diff. I changed the old diff fluid after some howling noises coming from the front of his x5 at basically all speeds in both drive and neutral. Thought it may be the wheel bearings but after changing the fluid for him, there looks to be some small metal shavings in the oil. I added a friction modifier as well when I changed his fluid and the noise seems to persist so he’s purchased a new diff and has asked me to install it.

I’m a little weary about taking on this job only bc it’s not my car and that i don’t know if I would have to drop the subframe or not. I have an x5 myself as well as an e90 lci 335i xDrive that I have done an oil pan gasket on. So I’ve dropped the subframe on ny e90 and still have the engine stabilizer bar I bought. I really only have 3 questions;

1.)I know you need to obviously pop out both front axle shafts but do you have to drop the subframe to do the front diff swap?

2.) If you do have to drop the front subframe and I decide to not take this on myself for my buddy, how much should the labor be for him to get his old front diff swapped out with the new one he has purchased and has in hand.

3.) Does anyone know a reputable shop in or around west Chester NY that could perform this work for a reasonable price?

[Juno01]

I've looked into swapping front and rear diffs and I don't see why you would need to drop the subframe for the front.

Removing the front axles I think would be the hardest part of this job. Maybe you wouldn't even need to remove the passenger side...

[GearHead335i]

Originally Posted by Juno01

I've looked into swapping front and rear diffs and I don't see why you would need to drop the subframe for the front.

Removing the front axles I think would be the hardest part of this job. Maybe you wouldn't even need to remove the passenger side...

I got under the car the other day and I’m pretty sure I’ll be able to unbolt it and then push it toward to rear of the car a few inches, and since the driveshaft would be detached, squeak by and lower it down without dropping the subframe.

What I also noticed is the input flange where the driveshaft mounts up to the diff is incredibly loose. I believe people refer to this as the pinion gear or pinion input flange? Whole diff will be replaced so should be fine after the swap but ironic that the noises began a few thousand miles after the dealership did the front driveshaft recall.

[davegt3]

Did you manage to get the diff out without dropping the subframe?

[GearHead335i]

Originally Posted by davegt3

Did you manage to get the diff out without dropping the subframe?

On my buddy’s x5 he had just taken it to a mechanic to get it done but funny you should ask bc I just did mine on my e70 35i. Managed to do it without dropping subframe ALTHOUGH I had to; Remove front driveshaft, undo both motor mounts, then Used my engine hoist to lift engine up a couple of inches and I ended up being able slide it in basically where the front driveshaft usually sits behind the thinner skinny bar on the subframe that goes across from side to side.

Granted, I had Recently removed and rebuilt my n55 engine and had the engine out and reason I had to install the front diff after engine install was bc it was just a lot easier to install without that front diff in the way. So again my front diff was already out before I did this but I don’t see why you couldn’t take it out the same method I got it in.