[N54Society]

I've been hearing a loud tapping noise which I've deduced to being something in or around the alternator. I've replaced the idler pulley, belt tensioner, deflection pulley, and the alternator clutch pulley. The noise is still there unfortunately. I think the only thing left is the bearings inside the alternator.

Anyone know what the correct bearings are for the OEM alternator in a 2008 E92 335i? Where can I buy these?

Thanks!

[pits200]

Buy a used alternator online. Got mine from a car with 40k for $100 and it's working like a charm.

[BruceJ]

B4 you spend money/attempt rebuild why not pull the Alt, take it to a shop and have it tested. You will be able to verify the noise. AZ/Advance usually have testers....

Good Luck
Bruce

[AaronZ34]

Don't take Bruce's advice of actually diagnosing the problem. Just keep throwing parts at it until it's fixed.

[sk55]

Rebuilderinabox. They sell like kits seems pretty inexpensive. Bearings. Brushes and voltage reg. Doesn't seem to hard.

[limitdown]

I replaced my alternator because of squeaky bearings. I wish I had taken the time to research the bearings to try a DIY. I buy various deep groove ball bearings and angular contact bearings for my saltwater fishing reels and RC cars, so I'm quite familiar with various bearing types. I'm sure that it would be easy to find the correct replacement bearing from Boca.

The first pic is the old alternator and the second is the new one that has been running in my car for about 10k miles now. Note that the Bosch part numbers are different.

My car is an August 2007 build E93 335i

Here's a thread I found on rebuilding the alternator of a 1998 528i. It looks very easy to do.
http://www.bimmerforums.com/forum/sh...Rebuild-for-30!

[muncie21]

run the motor with the alternator belt off and listen for the tick. If it's still there, it's not the alt

[N54Society]

Originally Posted by BruceJ

B4 you spend money/attempt rebuild why not pull the Alt, take it to a shop and have it tested. You will be able to verify the noise. AZ/Advance usually have testers....

Good Luck
Bruce

Thanks for the advice. I think I've replaced everything that could contribute to the noise and on Monday I'll be bringing my alternator in to a repair shop for testing. He should be able to diagnose a bad bearing along with how well it's building amperage.

Originally Posted by AaronZ34

Don't take Bruce's advice of actually diagnosing the problem. Just keep throwing parts at it until it's fixed.

Too late. I've already replaced everything. I'm at 115k miles btw, so those pulleys needed replacing anyway.

Originally Posted by sk55

Rebuilderinabox. They sell like kits seems pretty inexpensive. Bearings. Brushes and voltage reg. Doesn't seem to hard.

Thanks! It's hard to find the right one for our alternator though. I don't see BMW listed under rebuild kits.

Originally Posted by limitdown

I replaced my alternator because of squeaky bearings. I wish I had taken the time to research the bearings to try a DIY. I buy various deep groove ball bearings and angular contact bearings for my saltwater fishing reels and RC cars, so I'm quite familiar with various bearing types. I'm sure that it would be easy to find the correct replacement bearing from Boca.

The first pic is the old alternator and the second is the new one that has been running in my car for about 10k miles now. Note that the Bosch part numbers are different.

My car is an August 2007 build E93 335i

Here's a thread I found on rebuilding the alternator of a 1998 528i. It looks very easy to do.
http://www.bimmerforums.com/forum/sh...Rebuild-for-30!

Thank you for the really informative post! This post should be a sticky by itself. I'm going to take my alternator in to a rebuild shop to see how much they charge for new brushes and bearings (parts only) and then ask how much they would charge if they replaced the parts for me. If it's not much more (considering the alternator is out of the car now), I'll just have them rebuild it for me.

This is my alternator:

Originally Posted by muncie21

run the motor with the alternator belt off and listen for the tick. If it's still there, it's not the alt

Tried it. Killed my battery. So now I'm going to buy a new battery to see if that's what was causing the squeaking.

[beto17]

Originally Posted by vbp6us

I've been hearing a loud tapping noise which I've deduced to being something in or around the alternator. I've replaced the idler pulley, belt tensioner, deflection pulley, and the alternator clutch pulley. The noise is still there unfortunately. I think the only thing left is the bearings inside the alternator.

Anyone know what the correct bearings are for the OEM alternator in a 2008 E92 335i? Where can I buy these?

Thanks!

Dont know about where you leave but here in georgia there is some shops that rebuild starters and alternators. Do some search i bet you can find a local shop around your area they do a good job..

They normally charge between 40-60

[sk55]

Originally Posted by vbp6us

Thanks for the advice. I think I've replaced everything that could contribute to the noise and on Monday I'll be bringing my alternator in to a repair shop for testing. He should be able to diagnose a bad bearing along with how well it's building amperage.



Too late. I've already replaced everything. I'm at 115k miles btw, so those pulleys needed replacing anyway.



Thanks! It's hard to find the right one for our alternator though. I don't see BMW listed under rebuild kits.



Thank you for the really informative post! This post should be a sticky by itself. I'm going to take my alternator in to a rebuild shop to see how much they charge for new brushes and bearings (parts only) and then ask how much they would charge if they replaced the parts for me. If it's not much more (considering the alternator is out of the car now), I'll just have them rebuild it for me.

This is my alternator:





Tried it. Killed my battery. So now I'm going to buy a new battery to see if that's what was causing the squeaking.

you can call them direct and they can source the parts for you...

[N54Society]

Originally Posted by sk55

you can call them direct and they can source the parts for you...

Call Bosch directly?

[sk55]

Originally Posted by vbp6us

Call Bosch directly?

no just call the alternator in a box people. they were very helpful when i called.

the only thing the wears out is bearings... the brushes.... voltage regulator...

i think they said if there was clutch on the alternator you might need a special tool.


what do you need just the bearings? PM me ill see if i have a number for a bearing company... i did extensive research on this for another car a few weeks ago.