Alternator Rebuild

[David Layton]

Now that we are getting my 73 tii up and running, the alternator is squealing.  Chris suggested that it may be one of the bearings going out.   This is a tii, so the alternator will need to be rebuilt rather than replaced.  Is this a DIY project or better sent off.  If so, who is good?

[Mike Self]

I can't recall having an alternator bearing fail (277 and 227k miles respectively) although I'm sure they do.  So before delving into the alternator itself...

 

Make sure the squealing isn't a misaligned belt.  If the alternator mounts are the OEM rubber they're probably black goo...and will cause the alternator to sit catty-wampus (a technical term) in relation to the water pump and crank pulleys.  That can cause squealing.  That's an easy fix--new mounting bushings, preferably urethane.

 

mike

[Stevenc22]

David, see if you have a decent alternator rebuilder in your area. Mine cost $90 to rebuild my Tii alternator.

[Joesprocket]

I’m looking for one as well, pref on the mid-Atlantic. Like rad shops I fear they are becoming fewer and far between. 

[JohnM]

I got a rebuilt alternator for my "72 Tii last year which I found on ebay, It has 85 amp rating and an integral voltage regulator. I believe it was off a BMW 310 originally. The seller was a rebuilder in   CA and as I recall, it cost around $300  delivered to me in CT.

[SydneyTii]

 

 

17 hours ago, Mike Self said:

catty-wampus

 

That’s brilliant Mike, my father in law had a never ending dictionary of those technical terms, he even sent my daft brother in law up the spares shop to ask for a doofer, to be fair he was pointing at the part and said “you know just get one of those doofer things”  so off my brother in law trotted and asked for exactly that🙄

@David LaytonMy Tii had a 5 series alternator, it can be run with a properly machined spacer, it is internally regulated so you need to do a very simple wiring mod and away you go. I went back to a Tii one I had laying around as I don’t run any real draw and wanted to test it, I  also fitted the toothed adjuster someone on here makes.

['76mintgrün'02]

If it does turn out to be the bearings making noise and it's charging as it should, you could just replace the bearings yourself.  I don't recall the sizes off hand, but have the old ones I took out up in the shop and I could get the numbers off of them if you'd like.  They're a common size and relatively cheap.  I had fun working on mine.  Here's a post showing some of what was involved.  It's been working fine.

(bad link, see the post below for a better one)

Tom

Edited August 17 by '76mintgrün'02
bad link

[paulyg]

I'd also benefit from the bearing specs, swapped in a spare alternator because the bearings in the original were growling. 

['76mintgrün'02]

Okay, I'll find the old ones and report back with the numbers.

 

For some reason, the link I posted above is going to the top of the next page of the thread.  This link takes you to the previous page and my post is the second one down.

 

https://www.bmw2002faq.com/forums/topic/201295-what-did-you-do-to-your-2002-today/page/725/

 

RealOEM lists the bearings' dimensions and BMW part numbers, but only one of them is still available.  Googling those dimensions brings up a lot of shopping options.

 

 

 

No.	Description	Supp.	Qty	From	Up To	Part Number	Price		Notes
01	Hex nut		1			12318602176	$0.86		ENDED
02	Wave washer	B14	1			07119932149			ENDED
03	Pulley		1			12311356300	$18.70		ENDED
04	Fan wheel		1			12311350199	$14.54
05	Fillister-head screw		1			12311350346			ENDED
06	Washer	A5,3-140 HV-ZNS	3		07/1977	07119931029	$0.40		ENDED
06	Washer	10X5,3X1-200 HV	3			07119904206
06	Washer	5,3-140 HV-ZNS	3			07119936439	$0.40
08	Housing assy front		1	02/1962	07/1977	12311350338			ENDED
09	Grooved ball bearing	40X17X12	1			12311714522	$17.93		ENDED
10	Supporting plate		1			12311459279	$1.12
11	Rotor		1	09/1965	07/1977	12311350331			ENDED
12	Slip ring		1			12311354689			ENDED
13	Grooved ball bearing	32X12X10	1			12311739203	$21.20
14	Repair kit rotor		1			12311350332	$14.45

 

Tom

[uai]

This is the newer sealed type you need 1 of each
Rillenkugellager 6203 2RSH/C3 Kugellager 6203 2RS.C3 17x40x12 mm

Rillenkugellager 6201 2RSH/C3 Kugellager 6201 2RS.C3 12x32x10 mm

And while you're in there get new contact carbon

 

Edited August 17 by uai

[2002iii]

4 hours ago, SydneyTii said:

 

 

 

That’s brilliant Mike, my father in law had a never ending dictionary of those technical terms, he even sent my daft brother in law up the spares shop to ask for a doofer, to be fair he was pointing at the part and said “you know just get one of those doofer things”  so off my brother in law trotted and asked for exactly that🙄

@David LaytonMy Tii had a 5 series alternator, it can be run with a properly machined spacer, it is internally regulated so you need to do a very simple wiring mod and away you go. I went back to a Tii one I had laying around as I don’t run any real draw and wanted to test it, I  also fitted the toothed adjuster someone on here makes.

Reminds me of the guy in my automotive class that spent an hour looking for muffler bearings and headlight fluid!

[SydneyTii]

Well I did once send my sparky apprentice to the wholesalers for Fallopian tubes instead of fluorescent tubes…. He still hasn’t forgiven that (and all the others) 😂

[jimk]

17x40x12

Self aligning roller bearing | 123Bearing

WWW.123BEARING.COM

---

Find your self aligning roller bearing on 123Bearing. Good quality/price ratio! The ideal bearing to compensate your misalignments on your assemblies.

32x12x10

 

123Bearing | Bearings, belts, seals, rod ends

WWW.123BEARING.COM

---

More than 10 million parts in stock at 123Bearing. Bearings, belts, seals and rod ends at the best price and available in stock. Fast delivery!

 

Edited August 17 by jimk

[visionaut]

FWIW, Section 10 of the Service Repair manual has 6 detailed pages covering how to rebuild the alternator…

 

[kbmb02]

1 hour ago, visionaut said:

FWIW, Section 10 of the Service Repair manual has 6 detailed pages covering how to rebuild the alternator…

 

The rebuilder I use does things such as secure the internal wire connections (with epoxy) for an even-longer lasting unit (I like this for race cars, where things vibrate a bit more). -KB