Gotta vent-alternator install. (SOLVED-don't forget to tap that lower nut flush!)

[M3Bob]

This is what i get for telling folks how BMWs are DIY friendly. I'm in the process of replacing my alternator, and the old one came out without too much fuss. Took some wiggling around the oil tubes, but wasn't bad at all. The install on the other hand....has been a multi-hour marathon of frustration. I'd have to say it's second only to trying to bolt up the rear diff. (maybe because it -should- be easy). First, the new alternator (rebuilt Bosch, yes i know....) is a VERY snug fit on the oil housing. So much so i had to take a file and get the paint off the mating surfaces. Second, trying to get both bolts in has been an absolute nightmare. The top bolt (w/ the pulley) is usually not too bad. The bottom one...I've yet to get it to thread on either by itself or after using the top bolt to theoretically align things. The threads are in good shape (bolt and alternator) so that's not it...it's just trying to get the damn thing to line up.

At this rate i might take a few mm of threads off the bottom bolt so (maybe) it'll self-align.....

GRRRR.

OK, vent over.

[M3Bob]

OK I figured out how to make it work (and while some of the DIY videos don't capture the step...FCP did). You really need to tap the captive nut on the bottom so it's flush w/ the alternator body before doing the install. Once i did that, took about 5 minutes to bolt it up. C'est la vie.

[PSUEng]

My new Valeo dropped right in; fighting the old one to get it out was the hassle I had.

[M3Bob]

Can’t complain too much. This is the original alternator…so 220k miles on it! Took it apart and the brushes are almost gone, but wore evenly. I may slap in a new voltage regulator and keep it as a spare.

[bavarian3]

Yeah looks like you solved it but I also learned this the hard way last week.

This thread is of relevance: link

[PSUEng]

Can’t complain too much. This is the original alternator…so 220k miles on it! Took it apart and the brushes are almost gone, but wore evenly. I may slap in a new voltage regulator and keep it as a spare.

I thought about doing the same, until I priced the Valeo VR and compared to a new Valeo alternator, it's a little less than half the money--and, you still have old bearings, etc. If I'm doing an alternator job, I'm putting a brand new unit it. So, depending on your budget, if you want to keep a spare alternator, I'd get a brand new Valeo 439317.

[Black107]

My Valeo replacement went in pretty uneventfully, but some time later when I had it back off the car to do my oil filter housing gasket, it didn't want to go back on easily because that insert had peeked out a bit. Banged it back in per FCP's diy and it slid right in.