Separating fan housing and alternator
 

I removed the fan housing to put in a new alternator. for my '87 911. I looked over the advises from this board before working on it.

The advises are:

1.Hammer on the 6 studs.

2. Drop the housing on the ground, turn 180 degrees, drop again to knock out the alternator

None of the above methods worked for me. I do not recommend knocking or dropping or hitting the fan housing. The housing is made of aluminum(correction- not aluminum, it's magnesium). Very fragile and soft. You can crack the case easily. The housing and alternator was also very tight. I went to Sears and purchased a $49.99 3-jaw puller. I already have a Sears heat gun. I placed a steel plate on the center of the alternator for the pushing rod to push against. I first tired to pull without heating up the case. The pressure was so great if I keep turning the puller, the 3 jaws will rip open the fan housing. I then heated the fan housing all round for 5 minutes. After that, I started using the puller again. After few turns, a popping sound, the housing and alternator just separated. I know there is a "pro way". But remember, only the pro can do it safely. I would recommend using the method suggested by the Porsche factory- using a puller.

Fan housing
http://forums.pelicanparts.com/uploa...1177957397.jpg


Using puller
http://forums.pelicanparts.com/uploa...1177957446.jpg

Separated. No damage. Heat gun and puller and the lower corner
http://forums.pelicanparts.com/uploa...1177957468.jpg

knock on a wood block or a folded stack of rags. not on the concrete. a good firm knock, not granny style. they always come out for me that way, and $49.95 cheaper too.

You did the right thing. For the record, the housing is cast magnesium and they are prone to cracking if abused. Whacking puts a lot of stress on the four arms that connect the center section to the outer diameter. I think some spray lube between the alt and the mount might have also helped. Heat and puller is the kind way to go. You might want to clean the corrosion from the center of the mount before re-installing the alt...not sure if some anti-seize would help for the next time around.

I'll vouch for John's method. I've probably done a dozen this way.

Always works.

I was able to get mine out with method #2, after cleaning with solvent and liberally soaking with PB Blaster overnight.

For the record, I dropped it from an elevation of about a foot onto a couple soft pine 2x4s laying on a concrete basement floor. Third time was the charm. I stuck a few thicknesses of carpet padding below to cushion the alternator's fall.

PS: For extra fun, also try removing either the rear lower shock bolts or the front bearing dust caps. Many hours of pure joy await you.

Joe