Leaking Fluid under Transfer Casing

[Terp335]

Has anyone else experienced this? My 35d has 2100 miles on it and I'm surprised to see fluid, what looks like oil, leaking from it.

[Terp335]

Stock down BMW. Dealership confirmed a rear differential fluid leak. Headed back in on Monday to get the casing taken apart and re-sealed.

[42pilot]

Is it the rear-end or the transfer case?

[Terp335]

Originally Posted by 42pilot

Is it the rear-end or the transfer case?

Rear differential. You can see a small little drip in the attached pic. I'm hoping this isn't telling of more issues to come. ....I'm staying positive.

[Kzang]

That is disheartening on a new vehicle. Did the Service Advisor provide any answers to why this happened?

[Terp335]

Originally Posted by Kzang

That is disheartening on a new vehicle. Did the Service Advisor provide any answers to why this happened?

I spoke with the tech who inspected the car and he said he's seen it before on a few new cars and it's likely from a bolt that was not tightened all the way during install at the factory. He could be blowing smoke....

[Kzang]

Originally Posted by Terp335

I spoke with the tech who inspected the car and he said he's seen it before on a few new cars and it's likely from a bolt that was not tightened all the way during install at the factory. He could be blowing smoke....

Damn american workers! Keep us updated and I hope it gets resolved.

[42pilot]

Originally Posted by Terp335

I spoke with the tech who inspected the car and he said he's seen it before on a few new cars and it's likely from a bolt that was not tightened all the way during install at the factory. He could be blowing smoke....

Either that or they didn't apply enough sealer. It's no concern - let them fix it and you'll probably never see this again. Thanks for the pic.

[Terp335]

The dealer completed the repair on Tuesday and so far not more leaking. They replaced the old gasket and seal with new, flushed the fluid and filled with new differential oil. I wish I had a picture, but the tech drove it out of the service bay with 5 do not wash signs on it for me.

My only other gripe about this car is the off gassing of the interior that caused a nasty film on the windshield (at least I'm assuming this is what has caused the film). Windex just causes streaks so I had to use a mixture of vinegar and water to remove it.

[tvnewsmom]

Have you had any problems after the fix? I was just told I need a new differential and my car only has 12,000 miles!

[Terp335]

Originally Posted by tvnewsmom

Have you had any problems after the fix? I was just told I need a new differential and my car only has 12,000 miles!

Yikes. Sorry to hear and glad it's under warranty. I've got just shy of 6k miles on our X5 now and haven't had another issue. Did you notice any oil spots? I'd suppose a slow drip over 12k miles would cause it to go bad for sure.

[tvnewsmom]

Yes. There were spots on the garage floor. I crawled under the vehicle and noticed it all wet. That's when I called for service. It's been in the shop since Thursday.

[Terp335]

Update: After our first oil change with DEF service (2wks ago) I'm now seeing oil spots under the differential again. All was good since they took the casing apart and sealed it in July (a few weeks after we bought the car). I can't figure out what would trigger this after an oil service....I don't believe in coincidence. I'll be taking it back to the dealer for service on Monday.

[Terp335]

Just got under the car and took a picture. I'm no mechanic but given the moisture on the outside of the casing (all oil) I don't think that it should be driven much if it can be avoided. Anyone seen this on their X?

[JonM]

Originally Posted by Terp335

Just got under the car and took a picture. I'm no mechanic but given the moisture on the outside of the casing (all oil) I don't think that it should be driven much if it can be avoided. Anyone seen this on their X?

I think you are OK to drive the car short distances, but you need to get to the dealer as soon as they can get you in. I looked at the parts catalog here:

http://www.realoem.com/bmw/enUS/show...diagId=33_1769

I am surprised there is no gasket for the differential cover. They use Locktite on the F15. Never seen that before on a BMW differential. By the same token, it looks like there is a fill plug for fluid (part #3) but no drain plug. To me, that means they want us to remove the diff cover to drain. Bummer.

Either way, IF the leak is at the cover-to-case connection, they need to clean (properly) and re-seal with Locktite 5970 and properly torque the cover to specs using the proper bolt sequence. Usually, with many gasket makers, you are supposed to WAIT BEFORE REFILLING THE OIL so the gasket can cure, then fill and you are off. This can be 24 hours. A lot of people don't do that wait step.

There is also a chance the leak is at the output shafts or the input shaft. I can't really see that in your picture, but it's possible. My guess is they didn't get the fix right the first time. On the plus side, you get new diff oil - again - even though it is supposedly "lifetime" which some of us don't believe anyway.

[lowlevelhell]

Originally Posted by Terp335

Just got under the car and took a picture. I'm no mechanic but given the moisture on the outside of the casing (all oil) I don't think that it should be driven much if it can be avoided. Anyone seen this on their X?

Yes, I've seen it on ours. That's a very minor leak. Technically not considered a leak unless it drips at a certain rate. That would be classified by most mechanics as seepage. Wipe it clean and see how long it takes to return. Make an appointment and they'll fix it.

X5s are machines like anything else. These things happen in some form on all machines.

[lowlevelhell]

Originally Posted by JonM

I think you are OK to drive the car short distances, but you need to get to the dealer as soon as they can get you in. I looked at the parts catalog here:

http://www.realoem.com/bmw/enUS/show...diagId=33_1769

I am surprised there is no gasket for the differential cover. They use Locktite on the F15. Never seen that before on a BMW differential. By the same token, it looks like there is a fill plug for fluid (part #3) but no drain plug. To me, that means they want us to remove the diff cover to drain. Bummer.

Either way, IF the leak is at the cover-to-case connection, they need to clean (properly) and re-seal with Locktite 5970 and properly torque the cover to specs using the proper bolt sequence. Usually, with many gasket makers, you are supposed to WAIT BEFORE REFILLING THE OIL so the gasket can cure, then fill and you are off. This can be 24 hours. A lot of people don't do that wait step.

There is also a chance the leak is at the output shafts or the input shaft. I can't really see that in your picture, but it's possible. My guess is they didn't get the fix right the first time. On the plus side, you get new diff oil - again - even though it is supposedly "lifetime" which some of us don't believe anyway.

I'd suspect that left side half-shaft output as being a likely culprit.

[Terp335]

Thanks guys! I learn something new everyday on this forum. Lots of helpful people on here and always (usually) great replies.

I brought it in this morning....I'll let you know what they say. Based on the pics, I also suspect it's coming from the input/output on the left side.

The SA did mention a software update for the EGR valve/module. I asked, but he didn't have any information other than what was printed on the paper in front of him.

[lowlevelhell]

The suite of updates will take about 3 hours if you haven't had them done in the last 2 months or so.

[MattBianco]

Unless there is a warp, which is extremely rare, this is a build quality issue that is easily resolved. They tighten all bolts to a specific torque level, so my guess is poorly applied/missing sealant.

[Terp335]

I was in and out in under a day. They replaced the driver side rear axle seal (first incident was on the passenger side). Lets hope that this ends the debacle and I have no more rear differential issues. Unfortunately the EGR reprogram wiped all my coding...lol. I should have seen that coming I guess. Not a huge deal and easy to reapply but still a pain.

[lowlevelhell]

Do you do your own coding?