964 Alternator Fan replacement

[jovanybg]

Hello all.
I've just bought an 1994 Porsche 964 and found out that the Engine Cooling Fan/Alternator Fan has some cracks on it and would like to change it before it gives me more troubles!
I've looked on a technical articles on here and was not able to find article on only changing the Fan (w/o removing the Alternator).
Is that an option or should I go ahead and remove the Fan Housing together with the Alternator and only then change the Fan?
Thanks for your help!

[KNS]

The alternator is set into the fan and they come out as a unit. Once you get them out you can seperate the alternator from the fan. When it comes time to replace the assmebly back into the car, don't tighten the metal strap too tightly or you'll crack the housing.

[jovanybg]

Thank you KNS!
I was hoping I can just disconnect the belts, open the holding nut and pull out the Fan, leaving the housing and Alternator in place.
If that cannot be done I'm up for a bigger than expected job!
Thanks for your help!

[KNS]

jovanybg,

Go to the top of the page here and click on "tech info" and then on 911 tech articles. Look for the alternator replacement. It's for older 911s but the removal is nearly the same for the 964. It's not that difficult, I've done it a few times. You can remove the rubber air duct from the fan housing on the 964 for better access to the wires on the back of the alternator.

[LouZ]

The problem is that the fan is attached to the alternator by the fan hub. The hub allows the fan to turn independent of the alternator shaft. The fan hub is a press fit to both the fan and the alternator shaft.

It would be quite difficult to remove the fan while still in the housing. You will be best served to remove the entire ass'y and then remove the fan and hub from the shaft.

If you buy a new fan, it should come with a new hub already attached.

The best way to reassemble the unit is to place the fan in the oven and the alt in the freezer! Then the hub will slip on the shaft with very little effort.

Yea, it's a pain to disconnect and reconnect the alt wires, buy in the long run, it's worth it.

......and, yea, I just did it a couple of weeks ago.

[LPMM]

It looks daunting but it is actually a fairly simple job. I just replaced mine because it was delaminating and you can follow it here and here. I chose to also replace the voltage regulator and v-belts since I was already in there, depending on your mileage/condition you may want to do the same or skip.

PS: I bought this tool to do the job and it was the best $10 I ever spent. I was able to put a breaker bar on it and everything went smooth.

I hope this helps.

[jovanybg]

Hi LouZ and LPMM.
Thanks a lot for your replies!
Since you both recently changed the Fans, can I ask you where did you buy it, as our host - Pelican parts - have it for $620 which at least to me sounds a little bit expensive.

LPMM, you've mentioned guidance from another members. Can you forward me some of them?

Thanks again!

[LouZ]

Originally Posted by jovanybg

Hi LouZ and LPMM.
Thanks a lot for your replies!
Since you both recently changed the Fans, can I ask you where did you buy it, as our host - Pelican parts - have it for $620 which at least to me sounds a little bit expensive.

LPMM, you've mentioned guidance from another members. Can you forward me some of them?

Thanks again!

Got it from Sunset Porsche in Oregon. They are the best for OEM parts. Price was around $530, including the fan hub (that part alone is over $125)

[LouZ]

Originally Posted by LPMM

PS: I bought this tool to do the job and it was the best $10 I ever spent. I was able to put a breaker bar on it and everything went smooth.

I hope this helps.

Check your tool kit as that 12 point should be included!

[LPMM]

Originally Posted by jovanybg

Since you both recently changed the Fans, can I ask you where did you buy it, as our host - Pelican parts - have it for $620 which at least to me sounds a little bit expensive.

I purchased the following parts from Sunset Porsche.
(1) Engine fan 964.106.015.31 (includes hub bearing 964.106.051.30) - $419.05
(2) Belts 999.192.338.50 - $11.45ea
Skip the belts if yours are new.

The voltage regulator is crazy expensive from Porsche, so I bought one from EBS Racing, ~$12.

Originally Posted by LouZ

Check your tool kit as that 12 point should be included!

The factory tool is crap IMO, the Snap-On (or similar) is much better and allows you to use a breaker bar for leverage. just my $0.02

[LPMM]

Originally Posted by LouZ

It would be quite difficult to remove the fan while still in the housing. You will be best served to remove the entire ass'y and then remove the fan and hub from the shaft.

The best way to reassemble the unit is to place the fan in the oven and the alt in the freezer! Then the hub will slip on the shaft with very little effort.

Yea, it's a pain to disconnect and reconnect the alt wires, buy in the long run, it's worth it.

A couple notes... You have to tilt the fan housing in order to be able to put a 3-arm puller on the fan and have enough clearance to slide it off the alternator shaft. No big deal really and I never disconnected any wires from the back of the alternator, even when replacing the voltage regulator.

As far as reassembly, I just fitted the fan on the alternator shaft and it went in with no issues, no freezing nor warming anything. Lastly, when removing the pulleys and shims, be sure to place them in a way so that they go back the same way they cam off, the shims allow for the correct tension on the belts.

[jovanybg]

You guys rock!
Thanks a lot for your input!