Fan bearing sound...

morrisroad · 09-20-2009, 06:39 PM

The other day I noticed an odd clanking sound coming out of the engine bay. It seems to be coming from the fan area. Drove the car around and the sound was still there.

I did a few searches here and it could either be the fan bearing or alternator is toasted. There's a ton of great posts on how to repair but not much that presents what the problem might sound like before the fix. I've added a link to a small avi file that captures the sound.

http://www.youtube.com/watch?v=TrQJZA8Rfc0

Anyone hear this sound before this kind of failure?

Thanks!

jimq · 09-20-2009, 06:46 PM

check to see if the fan is hitting the shroud.

Tom W · 09-20-2009, 06:48 PM

My car is in the shop right now because I started to hear the fan hitting the shroud. I'll know in a day or two what caused it.

morrisroad · 09-20-2009, 08:37 PM

Looked around the inner shroud and it looked ok, no rub markings. I tried moving the blades and there was some minor play there. Not sure if there should be any.

Fred's 964 · 09-20-2009, 09:15 PM

Shouldn't be any play. Jimq can help with the DIY. He did a great job on his. He has pix he can share.

jimq · 09-20-2009, 09:27 PM

Quote:

Originally Posted by Fred's 964

Shouldn't be any play. Jimq can help with the DIY. He did a great job on his. He has pix he can share.

Morrisroad whereare you located?
We have a unwritten rule that you have to post pictures of your car before we will help you

Welcome to the fun by the way!

Hey Fred. Havent seen or heard from you in a long time. I think its getting near time to have a get together again

ValveFloat · 09-20-2009, 09:55 PM

I just finished replacing the fan and fan bearing (the whole hub actually) yesterday. Really the best way to check the fan and alternator is to remove the belts, then you can spin each separately and listen and feel the bearings. In my case it was obvious that the fan bearing was shot, as it was notchy and noisy.

Boeing 717 · 09-21-2009, 07:28 AM

Quote:

Originally Posted by ValveFloat

I just finished replacing the fan and fan bearing (the whole hub actually) yesterday. Really the best way to check the fan and alternator is to remove the belts, then you can spin each separately and listen and feel the bearings. In my case it was obvious that the fan bearing was shot, as it was notchy and noisy.

How hard was it to get the hub off the fan??? Mine seemed frozen to the fan when i had it out.

jimq · 09-21-2009, 08:15 AM

Quote:

Originally Posted by Boeing 717

How hard was it to get the hub off the fan??? Mine seemed frozen to the fan when i had it out.

I bought a 3 leg puller from Harbor Freight. My fan and bearing was stuck to the alternator shaft.

Crystal Cranks · 09-21-2009, 09:26 AM

Jim, nice assortment of persuading tools in that pic, looks like they got the better of you, is that blood on the floor.

ValveFloat · 09-21-2009, 11:41 AM

Quote:

Originally Posted by Boeing 717

How hard was it to get the hub off the fan??? Mine seemed frozen to the fan when i had it out.

Luckily I didn't have to remove the hub since I was replacing the fan as well. My old fan was coming apart.
Judging by the force necessary to put the new hub in the new (used) fan, I would say removing the hub is a job for a press, or a puller.
I searched for just the bearing, but no one seems to sell the bearing separate of the hub.

-Joe

elbeee964 · 09-21-2009, 11:52 AM

Quote:

...is that blood on the floor?

jimq · 09-21-2009, 02:06 PM

Quote:

Originally Posted by Crystal Cranks

Jim, nice assortment of persuading tools in that pic, looks like they got the better of you, is that blood on the floor.

I was sweating blood trying to get the darn thing apart without screwing up the altenator shaft!

Valveflot
Sunset porsche sells just the bearing. When I bought my new fan i ordered the bearing also. Turns out the fan comes with the bearing already in place so I sent it back to them. i seem to remember it was $106 for the bearing.

Boeing 717 · 09-21-2009, 03:22 PM

Quote:

Originally Posted by jimq

I was sweating blood trying to get the darn thing apart without screwing up the altenator shaft!

Valveflot
Sunset porsche sells just the bearing. When I bought my new fan i ordered the bearing also. Turns out the fan comes with the bearing already in place so I sent it back to them. i seem to remember it was $106 for the bearing.

Can you just replace the bearing while leaving the hub attached to the fan????

ValveFloat · 09-21-2009, 04:37 PM

Quote:

Originally Posted by jimq

Sunset porsche sells just the bearing. When I bought my new fan i ordered the bearing also. Turns out the fan comes with the bearing already in place so I sent it back to them. i seem to remember it was $106 for the bearing.

$106 sounds right for the hub with bearing. 28 in the attached diagram is the hub. The bearing is in the hub, but there is no P/N listed.

Quote:

Can you just replace the bearing while leaving the hub attached to the fan????

The bearing is held in the hub by a snap ring, so if you could find a replacement bearing, I don't see why it couldn't be replaced itself, without removing the hub from the fan.
When I find some time I'll remove the old bearing and get some measurements

-Joe

09-20-2009, 06:46 PM	#2
jimq Burgled Rennlist Member Join Date: Aug 2003 Location: Altamonte Springs, Fl/Gwynns Island, Va. Posts: 12,832	check to see if the fan is hitting the shroud. __________________ jim *Conservatives....We work hard so you don't have to* 91 White C2 Cab tiptronic 03 Black 996TT X-50 Grocery getter 2002 Dodge Ram 5.9L Gas Hog Bend-Pak Scissor Lift 64 230SL Mercedes (SOLD after 18 years ) Some other Porsche's

09-20-2009, 06:48 PM	#3
Tom W Addict Rennlist Member Join Date: Jul 2001 Location: Half Moon Bay, CA Posts: 3,950	My car is in the shop right now because I started to hear the fan hitting the shroud. I'll know in a day or two what caused it. __________________ -Tom 1992 964 track car (The Turtle) 2009 SL63 AMG

09-20-2009, 09:15 PM	#5
Fred's 964 Addict Rennlist Member Join Date: May 2006 Location: Altamonte Springs, Florida Posts: 411	Shouldn't be any play. Jimq can help with the DIY. He did a great job on his. He has pix he can share. __________________ Fred '91 964 C2 Cab - Grand Prix White, Black Top, Grey interior, 5 speed, White gauges, 17" 996 Turbo Twists, 55K miles '96 993 C2 Coupe - Speed Yellow, Black interior, White Gauges, 6 Speed, Factory Aero Kit, Sport seats, 18" 997 Carrera III wheels, Limited slip, Motor sound, LPMM, 54K miles

09-21-2009, 09:26 AM	#10
Crystal Cranks Addict Rennlist Member Join Date: Nov 2006 Location: Dublin Posts: 201	Jim, nice assortment of persuading tools in that pic, looks like they got the better of you, is that blood on the floor. __________________ 1990 964C2 Coupe

09-20-2009, 08:37 PM	#4
morrisroad User Join Date: Sep 2009 Location: Toronto, Canada Posts: 35	Looked around the inner shroud and it looked ok, no rub markings. I tried moving the blades and there was some minor play there. Not sure if there should be any.

09-20-2009, 09:55 PM	#7
ValveFloat User Join Date: Dec 2001 Location: MT Posts: 116	I just finished replacing the fan and fan bearing (the whole hub actually) yesterday. Really the best way to check the fan and alternator is to remove the belts, then you can spin each separately and listen and feel the bearings. In my case it was obvious that the fan bearing was shot, as it was notchy and noisy.