Rough idle after warm up. Hrmm...

[waters17]

When you rebuild it be very careful when you put it back together. The rear bearing sits in a plastic sleeve that is in the back of the case. It's very fragile and can easily break if that bearing doesn't go straight into the sleeve.
If your replacing the rear bearing you'll need a puller with some thin jaws. I bought one at autozone and ground it down. Think it was about 10 or 12 bucks.

Good to know. Do you know about how long it takes to do the rebuild?

[waters17]

I received the repair kit today. You weren't kidding about that plastic bearing retainer. Sucker is so fragile, it broke before I even unwrapped it from the packaging. Seems kind of stupid to wrap brittle plastic up with heavy bearings.



I contacted the seller and am awaiting a response.
--Seller is sending a replacement tomorrow. Looks like I'll be putting this off for another week.

What are my options here? I don't have access to a lathe either.

Anyone know what a standard part number for this piece is? <---Nevermind. I found a PDF containing all the part numbers. It's called a Tolerance Ring.

[jicaino]

That piece is there because the back of the water cooled alternator expands/contracts so much it would eff up the bearing and crack the casing if it weren't. I ordered another set when I saw it was on sale, if you can't get it I'll pop one off in delrin and send it along with the "previous" due order.

[waters17]

That piece is there because the back of the water cooled alternator expands/contracts so much it would eff up the bearing and crack the casing if it weren't. I ordered another set when I saw it was on sale, if you can't get it I'll pop one off in delrin and send it along with the "previous" due order.

Is that what they're made of? How's the other one you turned holding up? What kind of tolerances are we talking here?

My life would be so much easier if our shop would just buy a damn lathe.

[jicaino]

Is that what they're made of? How's the other one you turned holding up? What kind of tolerances are we talking here?

My life would be so much easier if our shop would just buy a damn lathe.

I don't know for sure as I threw it away. Delrin stock holds up better than injected. Typically, for press fitting different materials together you want to work within .003mm (.0013") tolerances. This has a high alloy steel bearing, pot metal casing and the plastic middle piece to accommodate very different expansion coefficient materials like the aforementioned 2.
I turned the new plastic piece to be firmly snug but still easily removable. The old ring was very brittle and turned to dust when pulled, but almost 15 years of high temps will most certainly have ill effects on almost every plastic, even space age materials such as rulon-j, delrin, and other modified acetals.

[JimLev]

Jaun, got any info you can supply on the plastic rear bearing sleeve?
Might be good to have a spare.

[jicaino]

Jaun, got any info you can supply on the plastic rear bearing sleeve?
Might be good to have a spare.

Hey Jim. I botched the one that came with the kit and turned a new one out of delrin stock. Easy peasy if you have access to a lathe. I didn't jotted down the sizes, but i do have another repair set coming my way (it could take a few weeks due to customs and such).
I was starting to think about alternate bearings for the alternator (pun intended) like all ceramic bearings, or better quality ones. I do have a lot of catalogs and specs to read. I would like to find bearings that works well when the alt is at operating temp (which is practically cooking itself).
That would involve getting a loose fitting bearing by a good quality manufacturer.
Will post a diy as soon as I finish playing around with one of my spares.

[waters17]

Hey Jim. I botched the one that came with the kit and turned a new one out of delrin stock. Easy peasy if you have access to a lathe. I didn't jotted down the sizes, but i do have another repair set coming my way (it could take a few weeks due to customs and such).
I was starting to think about alternate bearings for the alternator (pun intended) like all ceramic bearings, or better quality ones. I do have a lot of catalogs and specs to read. I would like to find bearings that works well when the alt is at operating temp (which is practically cooking itself).
That would involve getting a loose fitting bearing by a good quality manufacturer.
Will post a diy as soon as I finish playing around with one of my spares.

Here's the PDF file I found on Bimmerfest. It has part numbers for every part in the alternator. Looks like it's from a place out in California. Metro Auto Industrial.

Bosch Water Cool Alternator Unit & Parts Catalog.pdf

[jicaino]

Just to clarify on my bnearings pondering, a "loose fitting bearing" is poorly expressed. Bearings comes in tolerances. I meant high tolerance bearings, not the super duper snug ones. Some apps require a bearing that is on the loose side when cold, due to temp and/or operating speeds causing it to expand more than other apps.

[waters17]

Just to clarify on my bnearings pondering, a "loose fitting bearing" is poorly expressed. Bearings comes in tolerances. I meant high tolerance bearings, not the super duper snug ones. Some apps require a bearing that is on the loose side when cold, due to temp and/or operating speeds causing it to expand more than other apps.

I'm going to play it safe and buy the part.

[jicaino]

I'm going to play it safe and buy the part.

The seller didn't respond?

[waters17]

The seller didn't respond?

Lol, sorry. I misspoke. My mind must have been elsewhere. Yes they responded. They're going to send a new one.

[jicaino]

Lol, sorry. I misspoke. My mind must have been elsewhere. Yes they responded. They're going to send a new one.

Good!

[waters17]

jicaino, I just saw a resurrected thread about your ignition switch. The very brief reading I've done on the topic got me wondering if this could be one of my gremlins. Seems like some people have suggested that the worn out ignition switch could cause all sorts of electrical issues.

Every once in a while, I'll try to start the car and nothing will happen. This only lasts for a brief second, but long enough to trigger an emotional response. -It acts like I don't have the clutch pressed in all the way. It will only last for maybe a second, and has only happened maybe two or three times in the last month or so.


Since I just spent $85 on the alternator rebuild kit, I can't justify spending another $80 on an ignition switch. I'm going to rebuild the ignition switch this weekend and see if anything changes.

As of yesterday, I still haven't received my replacement tolerance ring. Hopefully it'll arrive today. -I am sort of wishing I had an extra.

[jicaino]

jicaino, I just saw a resurrected thread about your ignition switch. The very brief reading I've done on the topic got me wondering if this could be one of my gremlins. Seems like some people have suggested that the worn out ignition switch could cause all sorts of electrical issues.

Every once in a while, I'll try to start the car and nothing will happen. This only lasts for a brief second, but long enough to trigger an emotional response. -It acts like I don't have the clutch pressed in all the way. It will only last for maybe a second, and has only happened maybe two or three times in the last month or so.


Since I just spent $85 on the alternator rebuild kit, I can't justify spending another $80 on an ignition switch. I'm going to rebuild the ignition switch this weekend and see if anything changes.

As of yesterday, I still haven't received my replacement tolerance ring. Hopefully it'll arrive today. -I am sort of wishing I had an extra.

Whenever you think you can't justify springing a measley 80 bucks for some part you'll be refreshing consider this: We pay almost 3 times what you guys pay up there, once shipping and import duties are in the equation. And out currency is 15 to $1. There, now you can use that line when your significant other gives you a balls busting session about how much you spend on an old car.

[waters17]

There, now you can use that line when your significant other gives you a balls busting session about how much you spend on an old car.

LOL! That would not go over so well.

[waters17]

I decided against doing the alternator rebuild right now. I'm too worried about breaking the tolerance ring, so I ordered 2 more just in case. As soon as I have the extras, I'll do the rebuild. -Ordering today.

Here's a website where you can buy the tolerance rings for $5 each, if anyone is interested. Looks like they have a lot of the other rebuild parts too. My favorite part about that site is they list all the cross reference numbers for the alternator. Apparently the Bosch part number changes once the alternator has been rebuilt.

American Engines Co

[jicaino]

You loose points to no VR on that site.

[waters17]

You loose points to no VR on that site.

Are you sure about that?

Considering the parts on this site are labeled as 'aftermarket', I think the ebay kit you pointed me to was a really really good deal since they're probably the same parts.

[jicaino]

Are you sure about that?

Considering the parts on this site are labeled as 'aftermarket', I think the ebay kit you pointed me to was a really really good deal since they're probably the same parts.

They are indeed. They even come with a "warranty void if removed" label on top of the box.
There's an UK vendor who also has separate parts.
Points for both of us, we saved future e39 540i "budgetary concerned" owners (read: cheap) some bucks.

[waters17]

We all gotta do our part.


I cleaned the contacts on the ignition switch. No change. I might try another smoke test tomorrow.

[jicaino]

We all gotta do our part.


I cleaned the contacts on the ignition switch. No change. I might try another smoke test tomorrow.

I'm sure your alternator is F'd.

[waters17]

FINALLY! I got around to rebuilding the alternator. I stripped one of the 4 torx screws holding the face plate on. I hate how there's a tiny little section of metric fasteners at the hardware store. I've been shade tree wrenching for approx 15 years and I don't think I've ever encountered an imperial fastener on a car.
Anyway.. It was a super slow process drilling out the old screw. My son likes to use and lose my tools, so any drill bits I may have had were totally gone, and the drill itself was in his bedroom. All I had left was the Dremel.. Nope, he burned up the Dremel motor a few days ago. So I was left with using a Dremel grinding bit in the drill.

The torx screw was a countersunk M5-.8 x 30mm long. The only countersunk screws the hardware store had were 25mm long. I ended up buying a 30mm long socket head cap screw and using a rubber backed washer to compensate for the countersink. It worked out pretty well because the head didn't interfere with the pulley.

The lower bearing was also a chore. The loaner puller from Autozone was almost perfect, but the fingers were about .5mm too thick. I ended up buying a small puller and grinding the fingers down. Unfortunately, I ran into another issue. The opposite ends of the little spider legs were interfering with the center hub on the tool, so I wasn't able to get the fingers under the bearing because they were coming in at an angle. I ended up cutting the tops off so the legs could swing freely. -The angle grinder is definitely my favorite tool.

I sealed the whole thing up with red silicone. Man... It looks like a little kid rebuilt that alternator. -It works though.


I went for a 9 mile drive and monitored the voltages. -Idle is still rough. -maybe less? I don't know. Probably the same.

Previous voltages:
Never more than 13.8V
Usually bounced around between 13.4V and 13.8V
Sometimes dipping down to 12.9V

Rebuilt voltages:
I saw it spike up to 14.1V a few times
Usually bounced from 13.8V to 13.9V -mostly 13.9V
Idle voltages are kind of erratic. It dipped down to 13.2V then jumped to 14.0V

Back to hunting for vacuum leaks.

[JimLev]

Where did you get the parts from?

[waters17]

It was that ebay kit that Juan suggested. (LActrical/California Alternator and Starter) After I bought it, I started searching for alternator parts suppliers, and found a few. It looks like it's all unmarked Chinese products everywhere though. -I attached a PDF with part numbers on post #61 of this thread.

Here are a few places I found after I bought the ebay kit.

Wagner Alternators & Supplies, Inc.

American Engines Co. -I ordered some tolerance rings from them. When the package arrived in the mail, there was a note from the postal carrier saying I owed $0.75 postage.