Benton

I found myself in this same position recently; here's what I discovered:

The alternator case is two pieces, and the front half has a precision-machined edge around the circumference that slips cleanly into the magnesium shroud in order to locate it on center (to prevent the fan from contacting the shroud and keep the close tolerances). From the factory, this would have been a slip fit, but it appears that some now require some coaxing to release the alternator and fan combo from the shroud. Some tapping, with either a rubber mallet or a dead blow hammer, on the back of the alternator shaft, should release the fan + alternator combo from the shroud.

Once out, have a look at the machined edge that slips into the shroud to understand why this is the case. If this edge were not machined, they would be relying on the imperfect cast housing to locate the alternator--and thus, the fan--within the shroud. It may be that either the magnesium shroud/housing is not exacting with the tolerances, or that the various alternators (possibly from multiple Bosch factories) do not have exact tolerances, so some of us ended up with "tight alternators" and others did not...?

benjr

Keith

How did you get he alternator out of the shroud. I installed a Bosch rebuilt into a recently powder coated shroud. I oriented the alternator wrong and now I can't remove it. I didn't want to damage the shaft so I fashioned a pipe to fit over the shaft so the pressure is applied to the alternator case. I have been whaling on it and won't budge. Trying liquid wrench as well ??

kjr914

Deja Vu.... This is EXACTLY what I had happen. It looks something like this:

First thing first.....STOP beating on the alternator. Trust me.

I wailed on the shaft and back of the housing with a BFH and a block of wood, I tried a socket that slipfit over the shaft to push on the housing..... And eventually I cracked the back housing, as it is NOT very structural solid, after all...

This happened at 9pm the evening before an autocross with my (that day) newly powder coated fan. Misaligned it so the wires out the back sat on the engine block (would have melted, shorted, causes sparks, fire, etc most likely), luckily I caught it. I broke the back of the housing, then had the whole thing rebuilt, it made noise, had it rebuilt again, and its in the car now making a lot of racket. A Bosch rebuilt unit is sitting in the garage waiting... I bought that last summer, and it was a while before that when I broke the F'n thing in the first place.... Needless to say, I've been burying this one deep at the bottom of my todo list, due to the painful memories...

Eventually, I got it out by hammering on the already broken alternator. And I sanded down the new PC in the interior of the shroud to get the rebuilt (rebuild#1) alternator to slip fit better. In hindsight, I would have painted it, not used PC (sorry to tell you now).

As for your dilemma, I'd use some penetrating oil or heat/cold and find a way to use a gear puller to apply gentle and constant pressure to pull/push the alt out of the shroud. Maybe 2 gear pullers in a push/pull setup? Or maybe some time in the freezer might help, but I'm not sure of the coefficient of expansion on the alt housing vs shroud....try that and/or heat to see what works.

Sorry not to have anything better to offer. Perhaps the RL brain trust will cook up something. I feel for ya....

pcar

I was faced with the same problem there was no way the alternator was going to come out of the housing peacefully. So I put the whole thing in the oven at 300 degrees for about 5 min and that's all it took the alternator fell right out of the housing. Hope it helps someone!