darndest driveshaft center bearing ever?

[ross1]

I'm sharing this less than exciting story to hear if anyone else has seen or heard of this.

In the spring of 2016 which is about 40k miles ago my wife's 528i began making the scraping noise a dry bearing makes. Coming from the trans tunnel area I knew it was the driveshaft center bearing. I ordered a new OE bearing w/support and giubo which I had in hand a few days later.
Meanwhile the noise quit. I figured I'd misdiagnosed the noise and something had been rubbing on the driveshaft.
Perhaps half a dozen episodes like this occurred over the next three years, each one lasting a day or so then quiet again. None of the heat shields were rubbing on the shaft which I had speculated about. It was the bearing but it would quiet itself after a while so I just ignored it not wanting to do the job which entails exhaust work.
Land the plane, Ross.
A few days ago it started again and it was clear it wasn't going to stop this time. The noise was different and varied from the familiar scraping sound to a whir and sometimes a whine like a jet engine spooling up(that was sort of fun), it varied each time I would accelerate and would go away (inaudible frequency?) around 50 MPH. There was never any vibration felt.
Parts had been on the shelf nearly three years now and a friend offered his service bay for the day so I finally changed it yesterday. 34 months and ~40,000 miles after it first began protesting.
Has anyone ever seen a bearing act like this before? I thought this was rather remarkable. Bearing was dry as death valley and noisy but still did not show signs of overheating and has no discernible play.
I did a little quick math and after some 245k miles this little devil has seen a bit more than 811 million revolutions.E39 center brg 001.jpg

[Ed CT]

That is rather remarkable. Maybe when it acts up, a piece of the solidified grease breaks off, goes for a few revolutions, pulverizes into an ultra-fine dust compound which glazes over any galling on the races, and then carries you for another few months. Or, maybe not.

Did you also change the CV joint when you R&Rd the CSB & Giubo?

My 528 started making a light chirping noise, only in cold weather, that I noticed about 5 years ago at about 150k miles (now at 217k+). The chirping was not there for the other three seasons. I thought it was either the CSB or CV joint. I haven't noticed it this winter, though. And, like you, I ignored it as it wasn't that severe a noise, didn't vibrate, and involved exhaust work (my least favorite DIY).

[ross1]

"Maybe when it acts up, a piece of the solidified grease breaks off, goes for a few revolutions, pulverizes into an ultra-fine dust compound which glazes over any galling on the races, and then carries you for another few months. Or, maybe not."
Seems plausible.

Mine never chirped but made all sorts of weird noises at the end.
Something to comfort you regarding the exhaust; An experienced exhaust shop mechanic was visiting at my friend's shop as I was beginning this project.
I asked his opinion of the crusty nuts and studs attaching the pipes to the manifolds. Should I just cut/burn them off now and use nuts and bolts or did he have any tricks for removing them w/o damage? He looked and said "looks like death" and he remembered being able to lower the exhaust enough to sneak out the heat shields and get to the bearing, then pull the shaft out towards the diff. Sure enough it was doable and those rusty exhaust manifold studs remain untouched.
It was VERY tight disconnecting the shaft as it needs to bend in the middle and with the exhaust in the way it required some persuasion.
I just cleaned and re-packed the CV, all is well.

[Ed CT]

Something to comfort you regarding the exhaust; An experienced exhaust shop mechanic was visiting at my friend's shop as I was beginning this project.
I asked his opinion of the crusty nuts and studs attaching the pipes to the manifolds. Should I just cut/burn them off now and use nuts and bolts or did he have any tricks for removing them w/o damage? He looked and said "looks like death" and he remembered being able to lower the exhaust enough to sneak out the heat shields and get to the bearing, then pull the shaft out towards the diff. Sure enough it was doable and those rusty exhaust manifold studs remain untouched.
It was VERY tight disconnecting the shaft as it needs to bend in the middle and with the exhaust in the way it required some persuasion.

Well, this is good to know and keep in the maintenance book notes section. Thanks.

Mine never chirped but made all sorts of weird noises at the end.

Meanwhile, I may just wait for the weird noises to start. LOL