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Need to replace differential. Unaware, please help!

2418 Views 9 Replies 4 Participants Last post by  smolck
Hi, so I own a 2003 325ci. Before my questions, I'll explain the problem to the best of my understanding. Just two days ago, I brought my car to an independent shop Bavarian motor experts (BME) for a routine oil change. They put my car on the lift, and begin a full inspection of the vehicle, during which they find a supposedly rare issue with my differential; The back left axel was popped out from the differential. They said there's a ring shaped piece that's missing, which is suppose to hold the two together. They suspect it may be inside the differential, but it would cost $550 just to take the cover off and see what might be wrong inside. They decided to go the cheaper route of pulling the axel out to inspect that for the missing piece. The mechanics determined that my only option was to schedule for another time that they could open the differential to find the problem(I overheard the manager telling the
mechanic that they didn't have time to deal with this problem on that moment), so the mechanic told me he would put the axel back as it was, which was described as really unreliable, and could fall out at any given moment. I was very hesitant for them to doing return the car to it's previous state, especially after its been taken apart already, but I agreed because the mechanic seems very honest. He came back after a while and said they were not able to even put it back into place because of the groove or whatever part the female part of the differential is called, was worn and gone?

I had to leave my car there and have it until Tuesday at the soonest, and that's only the mechanic found a used differential, or I pay for a new one, which was quoted at $2000. I've searched using car parts, and found a few different options, but none are opened on the weekend to call so far. My questions are:

1. How much can I expect to pay for shipping (to Honolulu), and for a used differential assembly.

2. My main source of info has been http://www.bokchoys.com/differential/Where.htm
I also read that a differential can increase torque, so would I be able to use one from a 330i/330ci, so long as it's from a manual transmission?

3. Finally, what Other sources(online or in Honolulu) are there to search for a new differential?

I'd appreciate any help. I really don't know how I'm suppose to handle this at all tbh.
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Sounds like a bunch of BS to me. The axle is bolted to the axle flange (which is part of the diff) and with it installed in the car, the axle flange cannot come off because it can't travel sideways enough to do so. And the flanges themselves are only held in by nominal pressure. To remove it, you simply pop it with hand pressure and it will come out. Unless your half shaft (axle) itself is bad, which is an easy DIY to replace anyways.

post some pictures or videos of it, maybe we can help. But DO NOT pay a dime until you talk to a competent BMW mechanic.

And I can get you a whole new diff (if it comes to that) for couple hundred bucks plus shipping.

EDIT: Just read where they said they can't put it back together. This is utter BS!!! The way the diff works makes the statements they are using utterly impossible.
Smolk - you beat me to it!!

A ring shaped piece that holds the 2 together???? Open the differential to try and FIND the problem? I'm not trying to be a total buzzkill here, but did the car drive fine before the oil change? If the car did drive fine before all this I would surmize that you are being RIPPED OFF!!! Go get the cops and get your car back and call your lawyer. The axel popped out or disconnected from the diff is A HUGE DEAL and I'm pretty sure the car would drive like crap, if it were even drivable at all. The axel doesn't just pop out. It's bolted in with 5 or 7 torx bolts if I remember correctly and it's as stong and beefy as an ARMY Tank.

Can I please have the phone number to this shop? My Flux Capacitor is running funny and I need to have someone check it out.
There are "C" shaped pieces that tie the axle bolts together, but they are for support and wouldn't let the car fall apart (likely you'd never notice), but as we both know, it can't be anything internal. The E46 just doesn't work that way.
Smolk - you beat me to it!!

A ring shaped piece that holds the 2 together????
Steele46,

RUN, don`t walk, away from that shop....they`re trying to scam you. Suggestion: when you go to pick up the car, bring a friend, dressed in a suit & tie, and introduce him as your attorney, and have him record the entire conversation with a camera or his phone.
Do NOT pay them for their "diagnosis" !
Thanks for all the replies everyone! Yes, my car was running perfectly fine before I drove in. I had the level 2 inspection from a dealership in february, and they found nothing wrong with it then, but that was before I drove from Ohio, to Wa state in 3 days.

The piece in question is number 15 in this diagram.


I really should have taken pictures because I really had no clue of what I was even looking at. From the picture below, The bolted part of the left axel, near the differential, is separated, one of those parts seperated, and a steel bar within it is what was keeping it together. They thought the ring might be inside the differential. They all claimed they've never seen this problem before
#15 is just the inner seal, it would cause a leak, but not a mechanical failure.

You need to see this video. Granted, it is an E36, but the design of the E46 is identical. Notice, NOTHING substantial holds the flange in place.

He did say that there was a leak, but it doesn't make any sense that a seal could be such a huge concern. What would you say to the mechanic in this situation? I don't mind paying to fix a real problem, but I don't want to be charged a lot of money to fix something so simple. Also, Could you give me information on that differential that I could buy from you please? I would like to have something ready so that I'm not forced to pay for a new one, or be charged $20 daily for keeping it there, instead of having a new one installed that day. Thanks again for all of your help.
#15 is just the inner seal, it would cause a leak, but not a mechanical failure.

You need to see this video. Granted, it is an E36, but the design of the E46 is identical. Notice, NOTHING substantial holds the flange in place.
I'd ask him to show me exactly what the problem is (with the car on the lift) and what exactly is keeping the car from moving since it was driveable when you got there.

Then I'd tell him to suck it.

The fact is, unless I am missing something MAJOR I don't see how a leaky flange keeps you from driving (mine has leaked for a LOOONG time). The ring in the diagram is a SEAL not a structural or mechanical part.
What would you say to the mechanic in this situation?
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