Alt/Fan Belt Issue

[spb350]

I just bought a 85 911 and due to a oil overfill situation I haven't driven but around the block once. I have had it running in the driveway and noticed the fan belt is loose and making noises. I went out today after reading a bunch of posts about the shims and adjusting the tension. I think my problem is something else as I can spin the fan by hand partially around and then it gets tighter as I continue spinning and then it loosens up again as I come back around. The belt is not moving only the pulley. Is something bent or warped? What else could it be? Thanks

[grizzfan]

A stab in the dark here presuming that your setup is similar to my '75 engine.

Go ahead and try to adjust the shims. "101 Projects..." gives good instructions. Chances are that the belt, in becoming loose, caused one of the shims to offset slightly making the two-piece pulley seem tighter on one side, looser on the other.

Tom

[T77911S]

if you can spin it by hand, it is too lose. mine will spin with a wrench on it though.
it does not need to be tight.

if you are hearing noises, with the belt off, spin the fan. then start the car. its OK to run it with out the belt for a few minutes.

[rusnak]

First change the oil
Pelican Technical Article: Changing Engine Oil - 911 (1965-89) - 930 Turbo (1975-89)

Then tighten the fan belt.
Pelican Technical Article: Fan Belt Replacement - 911 (1965-89) - 930 Turbo (1975-89)

[DRACO A5OG]

Post a video please

[jlex]

If you were spinning the crank pulley (with or without the belt assisting) I'd say it's just the compression phase of the cylinders you're noticing which is normal. However, if the crank pulley is not moving & just the alternator pulley is moving then yeah, there's something wrong either with the shaft/bearings on the alternator, or as grizzfan suggests, something's hinky with the shims. A worn out or fractured pulley is another possibility. Get that pulley off & give it a good look.
Maybe all that oil got on the belt, and it's slick in one area and not another... Got another belt to try? If not, clean the entire belt & pulley with brake cleaner & see if it acts any differently

[spb350]

Originally Posted by rusnak

First change the oil
Pelican Technical Article: Changing Engine Oil - 911 (1965-89) - 930 Turbo (1975-89)

Then tighten the fan belt.
Pelican Technical Article: Fan Belt Replacement - 911 (1965-89) - 930 Turbo (1975-89)

Thanks for the articles, I was having trouble understanding why adding and removing shims would change the tightness.

Unfortunately my car didn't have the tool kit and I don't have a pulley wrench. Is there another good way grab the pulley?

[86 911 Targa]

Originally Posted by spb350

Thanks for the articles, I was having trouble understanding why adding and removing shims would change the tightness.

Unfortunately my car didn't have the tool kit and I don't have a pulley wrench. Is there another good way grab the pulley?

Check the classified for a fan belt pulley tool.


^^^^^
And then, try this.

good luck,


Gerry

[sugarwood]

Porsche 911 Fan Belt Pulley Tool - New: Accessories &amp Tools Related

[grizzfan]

You have to have the wrench!!!

Tom

[rusnak]

wtf Sugarwood....Pelian has it cheaper.

Porsche 911 (1974-1989) - Tools - Page 9

Or Part #. Enter into the search window: PEL-TOL-P209

[Driver_X]

Less shims, the closer the two pulley halves are and the belt rides higher up the "V" between the halves. More shims, the further apart the halve are and the lower the belt rides in the "V". Think of it as adjusting the diameter of the upper pulley to take up or remove tension on the belt.

There should be 6 or 7 shims (but never any less) and if you find you are not using them in between the pulleys, then the "extra" need to go outside the pulley, otherwise the nut with bottom out on the threaded shaft before it actually clamps the pulley onto the interior shims. IE: the nut will tighten, but the pulley will be loose ever so slightly. Always have 6 or 7 shims (sometimes you need 7 if the belt is new and can be a bit small) some in between the pulleys, and the balance outside.

Lot's of write ups on this.....

[spb350]

I took the nut off the pulley and this is what I found. I haven't looked but I'm hoping I can order the broken part and I will probably be getting the pulley too.

[sugarwood]

The thick cup shaped washer.
Is it bent inwards? It should be flat.

[sugarwood]

Anyone know what the broken part is?
I don't see anything missing.
Shims, pulley, cup washer, nut.
Do you think it was a crush washer that didn't belong?

[spb350]

The cup washer is flat.

I just looked real close at the broken part after looking on Pelican for a replacement and it looks like it is actually sheared off the fan housing, it may not be repairable. Any body else seen this before? I would hate to have to buy a whole new fan?

[bavaria911]

It appears there was an after market (inferior) metal washer installed to gap the pully for the slack in the fan belt or the riveted portion of the fan that holds all in place sheared off... But then again it could just be junk in the trunk !

Scott

Yes, I know what you are thinking.

[spb350]

Well I got it back together so now I can drive it a little while I'm working on it. I had to pull the fan off as the busted hub was needing to be ground down. I tapped a couple of the holes in the fan and then screwed some bolts in until it was pushed off the shaft worked pretty good. I ended up making a new hub from a thick washer and just fit where the original hub was. I put everything back together and the belt is now tight and the pulley is not wobbling like it was before. I put 3 shims on the inside and three out and cranked it pretty tight, no rubbing or squeaking so I think it okay for now.