crank pulley to shroud clearance

TerryH · TerryH's Garage

I have almost none and think there is contact there. My crank pulley measures slightly over 5 inches. Is this a stock measurement for an SC crank pulley? I would think there would be more of gap there even with an overtightened belt.

Since I bought the car last year, there has been a sound that I can only describe as aluminum-rattle-in a can like. I first thought maybe it was the old heat exchangers, but it's definitely more in the motor compartment. I haven't ruled out alt bearings. The belt is plenty tight, not too much deflection, maybe too tight.

So, either my pulley is too large or my alternator bearings are being stressed by the belt. Before I start mucking things up, I thought I would ask here. I definitely need to increase the clearance between the two.

TerryH · TerryH's Garage

Can someone with an SC or 3.0 please tell me how large of gap they have between the bottom of the fan housing and the top of their crank pulley? I need a reference here.

It occured to me that the fan housing doesn't move if the belt is overtightened, so that can ruled out, right? What changed the relationship between the fan housing (shroud) and the crank pulley?

The alt pulley and crank pulley appear to be lined up so fore and aft are probably okay, but I can't get .005 feeler gauge to fit between the fan housing and crank pulley.

Sonic dB · Sonic dB's Garage

loosen the strap that is holding the fan housing down. Take a crow bar and wedge it in underneath the fan housing. pry gently back to see if there is any "give". If so, then as you push the bottom of the fan housing back...re-tighten the strap on top of it that is holding it in.

It could be that the fan housing is not set back all the way...

yelcab1 · 04-17-2005, 01:58 AM

There is very little room, in fact the fan housing has a notch in mine.

ZOA NOM · ZOA NOM's Garage

What Sonic said. I had a similar issue, and it was resolved by loosening the shroud and repositioning it. My gap is only 1/8" or so, but it doesn't touch.

David · David's Garage

Something doesn't sound right. Can you change your belt without removing the pulley cover? It sounds like someone put on a larger pulley to change the A/C compressor speed.

Dynamik · 04-17-2005, 05:33 AM

I'm shooting in the air here. Sometimes people put larger diameter crank pulleys on to increase the speed of the fan. Also, I have seen a turbo crank pulley on a non-turbo car and the clearance margin was minimal. I actually had to remove the rear motor mount bolts and drop the rear of the engine just to put a new belt on. I changed the pulley because it seemed impractical to have a pulley set up that deleted the ability to change the belt on the side of the road. You need some clearance to get a new belt on the bottom pulley. Does your car have a/c? In other words does the pulley have one or two slots?

TerryH · TerryH's Garage

Thanks gang! I went out this morning and loosened the clamp on the housing and it moved away from the pulley. There is some clearance now, not much, but I can see daylight anyway.

Single pulley RoW car without air. That irksome noise is still there and I may have alt bearing issues still. I'm going to have to invest in a pulley tool or fab one.

Is it okay to run the motor without the fan belt connected for a minute or two to isolate the alternator for noise?

Thanks again for your assistance, guys. Can always count on this board to come to the aid of the less knowledgeable.

Joe Bob · Joe Bob's Garage

I did a alternator change a forgot the bushing behind the fan in front of the alt.....made a BIG difference.

Sonic dB · Sonic dB's Garage

"aluminum rattle in the can" may be the tensioners...have it checked out at a shop.

Dynamik · 04-17-2005, 09:04 AM

It will not hurt anything if you run the car for a minute or two without the alternator and fan spinning. The red light will be illuminated indicating the alternator isn't charging and obviously the heads and cylinders will heat up quickly. I have done this before to isolate a chirping noise that was coming from the fan/alternator assembly.
Good Luck!

TerryH · TerryH's Garage

Okay, with the belt off the noise is gone. If I twirl the fan by hand, there is a tick tick about once a revolution. I'm thinking bearings. Can they be replaced by themselves or do I toss in a whole new alt because I'm in there? Brushes and bearings or a new unit?

My motor is an embarrassment compared to the rest of my car. I want to powder coat the fan and shroud as they are heavily oxidized. I've heard not to paint the ends of the blades, anything else I should know before I take this stuff apart?

1981 SC RoW... do I have external voltage regulator?

yelcab1 · 04-17-2005, 11:08 AM

You have to remove the alt and have it rebuilt with the bearing pressed out and replaced. THis should run $150 with the bearing. Beats $300 or more for an alt.

TerryH · TerryH's Garage

Thanks, yel. So dropping in one of these $90 eBay jobs is a bad idea?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33573&item=7968350026&rd=1&ssPageName=WDVW

I put it back together for now so it will be available for a couple nephews to drive while they are out here on vacation this week. The noise the alt is making has been there for over a year, another week isn't going to hurt.

Now to find a local to Socal powder coater....