bpras@msn.com

Put about 1,200 miles on the car since purchase, started it up tonight and heard a high pitch whine, opened the rear deck and it was coming from the fan/alternator area. Shut the car off and l could see new light scratch marks on the fan housing.

Pulled the housing/alternator out and 2 of the fan blades are just starting to separate at the tip. The fan does not touch the housing when you spin it by hand but at speed they must be contacting the housing. I have seen several threads on this in the past. The prior owner stated the alternator was recently replaced (no receipt) but it is very clean and and the fan bearing appears to be new. The belts also appear to be new, I did mess up by not checking the belt tension with the Gates belt tension tool prior to taking it apart.

Questions:

1. Has anybody had a fan that appeared to be in very good condition have this problem? Did you try to trim a small amount of material off of the end of the fan tip to correct the problem.....did this work or did you end up replacing the fan?

2. What causes the initial problem of the fan blade tips separating?

3. I think I will replace the stock pulley assembly with a RS pulley. This will get rid of one belt and eliminate the bearings as a possible problem (and match the RS engine mounts I just installed). I have not heard of issues with this conversion unless you use a ton of electric options on your car at the same time. The question is do I replace the existing fan with a used part or try to repair the existing fan by trimming about 1/32 of an inch off the bottom of 2 blades? I will post some pictures when I separate the fan from the housing.

Thanks in advance, I will now start the 2nd home brew of the night.

The Brewmeister

Do you think the fan could have been dropped when the alternator was being replaced?
I am starting my second Lowenbrau of the night.

bpras@msn.com

Do you think the fan could have been dropped when the alternator was being replaced?

It does not look like that type of damage..... two of the fan tips are getting wider at the bottom. Looks more like oxidation. My avatar is a 92 964 witt 127K miles (for sale) I own and the fan are in the same condition but do not touch the housing.

The Brewmeister

I would replace the fan. Trimming two blades would cause the fan to be out of balance. It spins
pretty fast under normal operation. An out of balance fan will start to attack that new fan bearing.

tracke30m3

I had the same problem, worse actually. I had this really loud metal to metal clunking sound that scared the crap out of me the first time I heard it.

Scars on the fan housing confirmed the cause of the noise. I figured it was either the fan bearing or the alternator bearing though neither looked damaged or worn. Chose to replace the cheaper and easier to change part, no more noise after installing a new fan bearing. I think the bearing was about $60, a tedious (lots of small bits and pieces to remove/disconnect) but fairly easy DIY job.

Garth S

Remove the belts and check for radial play at the pulleys:if there is any, pull the fan and check for radial play in the alt shaft. That should tell the story on the bearings.
If there is any play, but the shaft apperas tight, pull the whole assembly and confirm that the 4 bolts that mount & center the alternator in the shroud are tight ( it was recently removed?).

As far as the fan blades, post a pic: these fans have a very thick epoxy type of coating, so you may not yet be into much metal .... if that is the case, I would get the fan bead blasted, hand finish & spray with a can of DuPont Duplicolour: mine still looks mint into its 3rd season - and the RS hub hasen't let me down re charging.

guards red

Some 964 fans are showing heavy corrosion now where the blade tips have split. I think this is what is likely to have happened to your fan and if so it's toast and you need a new one.

guards red

Here's a pick of a corroded fan...

jimq

I just went thru this on my 964. The blade was coming apart at the tips. $418 latter for a new fan and bearing a friend powder coated the housing and I was back in business. Sunset was by far the cheapest place to get the fan and to mine and their surprise it came with the bearing already mounted in the hub. Use a cheap Harbor freight bearing puller to take the old fan off if its stuck. My fan came off leaving the bearing so I had to pull the bearing off also. They can get really stuck after 10+ years.
I wouldnt advise buying a used one because they are not much cheaper from what I found and will also be in the same age range as your old one.

bpras@msn.com

Got the fan separated from the alternator and decided I will put in a new or used fan, depending on what I find available. The fan is not as bad as any of the pictures posted above, only one blade has a significant crack on back side towards the rear. What is interesting is the corrosion on the inner top of the lip. Ordered the RS pulley from Sunset (no affiliation) this morning before I pulled the fan off. Pulling the alternator is not one of my favorite jobs.

Any suggestions on ordering up a new or quality fan at a great price?

bpras@msn.com

Photos did not go with the last post.

jimq

Dont go used! There is no great price but Sunset was the lowest of all the places I checked.

bpras@msn.com

The new fan and RS Hub are supposed to arrive tomorrow. The new fan will have the standard hub already mounted to the fan. What is the best way to remove the hub from the new fan w/o damaging the the fan? I tried removing the hub from the damaged fan by tapping on it and it will not move.

I have a feeling I will have to take to somebody with a press to push it out.

AOW162435

I removed and replaced a few of these and used a nice, medium-sized, three-prong puller. I forget the brand, but it's made in the US and was on the shelf at Sears. Very nice piece. I just use a large washer or suitable socket to act as a foothold for the puller's center piece. Then I hook all three arms into the slots around the center of the fan. Works every time.


Andreas

bpras@msn.com

Andreas wrote That is how I removed the Fan/hub assembly from the alternator shaft. The hub has to be removed from the back side of the fan and I do not see a way to use a puller. I think the hub as to be pressed from the front of the fan and pushed out the back side. See the photos below: