Driveshaft Bearing Replacment

9352e90 · 09-11-2014, 05:53 PM

So I have been noticing a slight vibration when accelerating (under load). Mechanic confirmed the driveshaft bearing is shot. Whiteout removing the heat shild, what are the chances the flex disc also needs to be replaced? Or should it be done anyways?

udm328i · 09-11-2014, 06:27 PM

How many miles on car?,might as well do flex disc while car is up on the lift

alexwhittemore · 09-11-2014, 08:17 PM

I'm not sure if you have to replace all the bolts and nuts with the disc or not. If not, the disc isn't terribly expensive and at the risk the bad bearing has caused it to tear at all, you might as well. If you're going to pull the shaft to replace the bearing, it's not a lot of extra work to replace the potentially bad disc.

But if the disc doesn't appear to have any tearing or breakup, it's almost certainly fine. If yours is bad, you'll know it just by looking at it.

Efthreeoh · 09-12-2014, 05:01 AM

I'm not sure how the mechanic can confirm the center bearing is bad without removing the exhaust and heat shielding, but that's up to you to trust him. I've done this exact repair to my car at 230,000 miles. The flex disc on my car at 230,000 miles was in very good shape, but I replaced mine anyway since I bought the part already. I did get the new bolts (6 of them), but I really see no need to. They are big bolts with pinch nuts and are only torqued to around 50 pounds. I'd reuse them if I were going to replace the flex disk again and just use some Loctite on the nuts, which is what I did when I pulled the driveshaft a few months ago.

To remove the center bearing you need to split the driveshaft. There are two small isolators that BMW added to the parts, which may not be on your driveshaft. I just posted the info on another thread a few days ago.

alexwhittemore · 09-12-2014, 06:47 AM

Oh- when you pull the shaft, use whiteout to draw a line across the split so you can like it up precisely as it was before when you put it back together. Assuming they still use 2x universal joints rather than CVs, it's critical that they're lined up exactly.

9352e90 · 09-12-2014, 09:31 AM

Thx for the responses. It sounds like I might as well have them order the flex disc just in case and pay the 20% restocking fee if its not needed. The central bearing in squeaking at low speeds and there in noticeable vibration so I feel confident its worn out. My mechanic said 142,000 miles it isn't that surprising. 3 hours of labor sound about right?

Efthreeoh · 09-12-2014, 12:27 PM

I think that's an hour too long for a professional mechanic, but it's probably the shop rate. I did mine in under two hours the first time. I've got a lift and I have removed other BMW driveshafts before, so I was familar with the process. Considering you have a 142K on the car, replacing the bearing is not a bad idea any way. The flex disk is about $90 on line, so if you get it, you might as well use it. I do think the bolts are totally fine to resuse and that'll save you about $12.

They use universal joints still.

09-11-2014, 05:53 PM	#1
9352e90 Lieutenant 92 Rep 426 Posts Drives: f10 535i, e90 325i, e70 X5 Join Date: Dec 2011 Location: Michigan, USA iTrader: (0)	Driveshaft Bearing Replacment So I have been noticing a slight vibration when accelerating (under load). Mechanic confirmed the driveshaft bearing is shot. Whiteout removing the heat shild, what are the chances the flex disc also needs to be replaced? Or should it be done anyways?
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09-11-2014, 06:27 PM	#2
udm328i Lieutenant 57 Rep 503 Posts Drives: e92 Join Date: Jun 2009 Location: Westchester🇺🇸 iTrader: (3) Garage List 2008 BMW 328i [9.00]	How many miles on car?,might as well do flex disc while car is up on the lift __________________ ZSP/ZPP/BMW PE&PI/ BMW CF STRUT BRACE/ EIBACH PRO SYSTEM / H&R WHEEL SPACERS
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09-11-2014, 08:17 PM	#3
alexwhittemore Lieutenant Colonel 111 Rep 1,951 Posts Drives: 2009 Crimson 328i Join Date: Oct 2012 Location: Los Angeles iTrader: (0)	I'm not sure if you have to replace all the bolts and nuts with the disc or not. If not, the disc isn't terribly expensive and at the risk the bad bearing has caused it to tear at all, you might as well. If you're going to pull the shaft to replace the bearing, it's not a lot of extra work to replace the potentially bad disc. But if the disc doesn't appear to have any tearing or breakup, it's almost certainly fine. If yours is bad, you'll know it just by looking at it. __________________
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09-12-2014, 05:01 AM	#4
Efthreeoh General 17428 Rep 18,801 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I'm not sure how the mechanic can confirm the center bearing is bad without removing the exhaust and heat shielding, but that's up to you to trust him. I've done this exact repair to my car at 230,000 miles. The flex disc on my car at 230,000 miles was in very good shape, but I replaced mine anyway since I bought the part already. I did get the new bolts (6 of them), but I really see no need to. They are big bolts with pinch nuts and are only torqued to around 50 pounds. I'd reuse them if I were going to replace the flex disk again and just use some Loctite on the nuts, which is what I did when I pulled the driveshaft a few months ago. To remove the center bearing you need to split the driveshaft. There are two small isolators that BMW added to the parts, which may not be on your driveshaft. I just posted the info on another thread a few days ago.
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09-12-2014, 06:47 AM	#5
alexwhittemore Lieutenant Colonel 111 Rep 1,951 Posts Drives: 2009 Crimson 328i Join Date: Oct 2012 Location: Los Angeles iTrader: (0)	Oh- when you pull the shaft, use whiteout to draw a line across the split so you can like it up precisely as it was before when you put it back together. Assuming they still use 2x universal joints rather than CVs, it's critical that they're lined up exactly.
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09-12-2014, 09:31 AM	#6
9352e90 Lieutenant 92 Rep 426 Posts Drives: f10 535i, e90 325i, e70 X5 Join Date: Dec 2011 Location: Michigan, USA iTrader: (0)	Thx for the responses. It sounds like I might as well have them order the flex disc just in case and pay the 20% restocking fee if its not needed. The central bearing in squeaking at low speeds and there in noticeable vibration so I feel confident its worn out. My mechanic said 142,000 miles it isn't that surprising. 3 hours of labor sound about right?
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09-12-2014, 12:27 PM	#7
Efthreeoh General 17428 Rep 18,801 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I think that's an hour too long for a professional mechanic, but it's probably the shop rate. I did mine in under two hours the first time. I've got a lift and I have removed other BMW driveshafts before, so I was familar with the process. Considering you have a 142K on the car, replacing the bearing is not a bad idea any way. The flex disk is about $90 on line, so if you get it, you might as well use it. I do think the bolts are totally fine to resuse and that'll save you about $12. They use universal joints still.
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