Front output flange bearing failure

bhmax16 · 05-03-2015, 05:29 PM

Hey guys, I did a search but it doesn't look like anybody here has had this failure before. I crawled under my car yesterday to diagnose a drivetrain rumble I've been experiencing when letting off the throttle. I tracked it down to the front output flange bearing inside my transfer case, indicative from the excessive lateral play I found on the front output flange when wiggling the front driveshaft up and down (I removed it and the noise disappeared).

To clarify, the bad part is bearing #43 in the diagram at the following link: http://www.e90post.com/forums/showthread.php?t=799650

The car is a 2007 328xi coupe and has been babied since I acquired it in 2010 with 49k on the clock (now has 94k). I'm a former mechanic and perform all of my own maintenance and repairs (now working as an engineer). All fluids have been changed routinely. I have never experienced a drivetrain failure in any vehicle I've owned, including a Nissan Maxima that I drove to 200,000 miles, and a Jaguar XJ6 I drove to 167,000 miles, so this is not something I expect from a brand like BMW, especially with only 94k on the clock.

To make matters worse, it appears BMW does not offer this bearing for purchase, and instead requires one to replace the entire transfer case assembly, which is a $2,500 unit.

Does anybody happen to have a part number handy for this bearing? There is a good bearing supplier in my area who could match something up with a part number. Normally I'd pull my t-case and get the number myself, but that would result in me being without a driveable vehicle for many days. I'm single and live alone, so it's not really an option for me.

Any help or suggestions would be much appreciated. Thanks!

bhmax16 · 05-03-2015, 06:47 PM

Found a website that offers a bearing kit for the ATC300 (discovered them through a youtube video where a guy used their parts to rebuild an ATC400 transfer case).

http://cobratransmission.com/atc-300...kit-55162017-1

I'm assuming this kit should fit the 328xi even though the site states X3 and X5, since it's still an ATC300 transfer case.

I have an e-mail into the supplier to confirm.

KeepRidingDirty · 05-03-2015, 08:56 PM

Quote:

Originally Posted by bhmax16

Found a website that offers a bearing kit for the ATC300 (discovered them through a youtube video where a guy used their parts to rebuild an ATC400 transfer case).

http://cobratransmission.com/atc-300...kit-55162017-1

I'm assuming this kit should fit the 328xi even though the site states X3 and X5, since it's still an ATC300 transfer case.

I have an e-mail into the supplier to confirm.

Good find. You should snap a few pics of your rebuild. Interested to see one take apart this Transfer Case. I know of some servo motor failures, something like a worm gear? But I don't think too many people have replaced a bearing in their transfer case.

bhmax16 · 05-04-2015, 11:09 PM

Yes I was planning on taking photos of the process if there is enough interest here. I know plenty of guys have taken apart the chain driven cases like the ATC400 but I haven't seen anybody tackle one of our ATC300s. Looks like I'll be the guinea pig.

TheBigYahi · 05-05-2015, 09:15 AM

There's definitely interest here!

bhmax16 · 06-13-2015, 04:12 PM

Unfortunately I didn't snap pictures of the repair since a friend of mine, who has a shop, let me borrow his lift (he also lent a hand). I didn't want to waste time snapping pictures out of courtesy since I was on his time.

What I can say is that the job was relatively straight forward. Between the two of us, a lift, and air tools, we had the transfer case out, the new bearings in, and the transfer case back in the car in exactly 5 hours. This included taking a torch to the exhaust studs and swapping them out with new hardware, as well as cleaning the inside of the case real good. As my friend put it..."it helps when you have two people who know what they're doing."

No real major hangups throughout the job, though I can say the factory seal on the case is very tight and took some coercing to break free. We used a bearing splitter to remove the old bearings and a shop press to press the new bearings onto the gear. After that we took the gear and bearing assembly and drove it back into the case with a bearing driver. Nothing strange or magical here.

The output flange has some scouring, so I will be swapping that out next weekend. It is held in with a lock ring and pulls out of the transfer case the same way a CV axle pulls out of a tranny, so no need to pull the case apart to change that (thankfully).

All in all this is a job I'd say anybody with decent mechanical ability can tackle. If anybody runs into a similar issue and is interested in repairing their transfer case rather than dropping $2,500 for a new one, I'm more than happy to help walk you through the process in greater detail. Just shoot me a PM.

Take care guys.

05-03-2015, 05:29 PM	#1
bhmax16 Lieutenant 168 Rep 398 Posts Drives: '22 M4, '23 CX-50 Join Date: Jul 2011 Location: North Carolina iTrader: (0)	Front output flange bearing failure Hey guys, I did a search but it doesn't look like anybody here has had this failure before. I crawled under my car yesterday to diagnose a drivetrain rumble I've been experiencing when letting off the throttle. I tracked it down to the front output flange bearing inside my transfer case, indicative from the excessive lateral play I found on the front output flange when wiggling the front driveshaft up and down (I removed it and the noise disappeared). To clarify, the bad part is bearing #43 in the diagram at the following link: http://www.e90post.com/forums/showthread.php?t=799650 The car is a 2007 328xi coupe and has been babied since I acquired it in 2010 with 49k on the clock (now has 94k). I'm a former mechanic and perform all of my own maintenance and repairs (now working as an engineer). All fluids have been changed routinely. I have never experienced a drivetrain failure in any vehicle I've owned, including a Nissan Maxima that I drove to 200,000 miles, and a Jaguar XJ6 I drove to 167,000 miles, so this is not something I expect from a brand like BMW, especially with only 94k on the clock. To make matters worse, it appears BMW does not offer this bearing for purchase, and instead requires one to replace the entire transfer case assembly, which is a $2,500 unit. Does anybody happen to have a part number handy for this bearing? There is a good bearing supplier in my area who could match something up with a part number. Normally I'd pull my t-case and get the number myself, but that would result in me being without a driveable vehicle for many days. I'm single and live alone, so it's not really an option for me. Any help or suggestions would be much appreciated. Thanks!
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05-03-2015, 06:47 PM	#2
bhmax16 Lieutenant 168 Rep 398 Posts Drives: '22 M4, '23 CX-50 Join Date: Jul 2011 Location: North Carolina iTrader: (0)	Found a website that offers a bearing kit for the ATC300 (discovered them through a youtube video where a guy used their parts to rebuild an ATC400 transfer case). http://cobratransmission.com/atc-300...kit-55162017-1 I'm assuming this kit should fit the 328xi even though the site states X3 and X5, since it's still an ATC300 transfer case. I have an e-mail into the supplier to confirm.
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05-05-2015, 09:15 AM	#5
TheBigYahi Private First Class 44 Rep 167 Posts Drives: 2021 X5 45e Join Date: Jun 2014 Location: Syracuse, NY iTrader: (0)	There's definitely interest here!
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06-13-2015, 04:12 PM	#6
bhmax16 Lieutenant 168 Rep 398 Posts Drives: '22 M4, '23 CX-50 Join Date: Jul 2011 Location: North Carolina iTrader: (0)	Unfortunately I didn't snap pictures of the repair since a friend of mine, who has a shop, let me borrow his lift (he also lent a hand). I didn't want to waste time snapping pictures out of courtesy since I was on his time. What I can say is that the job was relatively straight forward. Between the two of us, a lift, and air tools, we had the transfer case out, the new bearings in, and the transfer case back in the car in exactly 5 hours. This included taking a torch to the exhaust studs and swapping them out with new hardware, as well as cleaning the inside of the case real good. As my friend put it..."it helps when you have two people who know what they're doing." No real major hangups throughout the job, though I can say the factory seal on the case is very tight and took some coercing to break free. We used a bearing splitter to remove the old bearings and a shop press to press the new bearings onto the gear. After that we took the gear and bearing assembly and drove it back into the case with a bearing driver. Nothing strange or magical here. The output flange has some scouring, so I will be swapping that out next weekend. It is held in with a lock ring and pulls out of the transfer case the same way a CV axle pulls out of a tranny, so no need to pull the case apart to change that (thankfully). All in all this is a job I'd say anybody with decent mechanical ability can tackle. If anybody runs into a similar issue and is interested in repairing their transfer case rather than dropping $2,500 for a new one, I'm more than happy to help walk you through the process in greater detail. Just shoot me a PM. Take care guys.
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05-04-2015, 11:09 PM	#4
bhmax16 Lieutenant 168 Rep 398 Posts Drives: '22 M4, '23 CX-50 Join Date: Jul 2011 Location: North Carolina iTrader: (0)	Yes I was planning on taking photos of the process if there is enough interest here. I know plenty of guys have taken apart the chain driven cases like the ATC400 but I haven't seen anybody tackle one of our ATC300s. Looks like I'll be the guinea pig.
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