Changing a Fan/Alternator Belt - Pelican Plea for help

[HarryD]

Today, I received a PM from a neophyte Pelican about getting the fan belt off of a car that has AC. He asked:

Hey man. I am a new owner and the alternator belt broke about a mile away from my house- I drove it home- the car never got over the first temp bar. I am having a tough time changing the belt. I have a manual and its unclear. How do I get around the aircond belt? Any advice you can give me would be greatly appreciated

I do not need to deal with this as my car no longer has AC installed.

As best I remember, you can loosen the AC compressor on it's mount to remove the AC belt.

Then you remove the Fan belt by holding the fan pulley and loosening the nut.

Install new fan belt, adjust shims to make belt tight (more shims between halves to loosen, less to tighten. Store the extra shims (6 shims total) outside of the pulley half beneath the fan nut. Reinstall AC belt and tension. Tighten every thing up.

[javadog]

You don't say what year car he has but, in general, you do have to take off the A/C belt. How to loosen it depends upon the particular A/C compressor installation.

You might advise him not to drive a car without a fan running. The oil temp will lag behind the engine temp.

JR

[vash]

loosen the AC compressor and slide it towards the inside..the AC belt will have to come off first. then the fan belt.

i remember it being really tight at the pulleys. he will need to finesse it a bit.

[dshepp806]

Easy peezy,..make sure he knows the shim adjustments,.....for proper belt tension..

Best,

Doyle

[86 911 Targa]

Originally Posted by HarryD

Today, I received a PM from a neophyte Pelican about getting the fan belt off of a car that has AC. He asked:



I do not need to deal with this as my car no longer has AC installed.

As best I remember, you can loosen the AC compressor on it's mount to remove the AC belt.

Then you remove the Fan belt by holding the fan pulley and loosening the nut.

Install new fan belt, adjust shims to make belt tight (more shims between halves to loosen, less to tighten. Store the extra shims (6 shims total) outside of the pulley half beneath the fan nut. Reinstall AC belt and tension. Tighten every thing up.

On our '86:

W/ A/C:

There are four bolts on the A/C compressor that needs to be loosened
along with the horizontal compressor belt tension bolt.

Slide the compressor to the left, and remove the A/C belt.

Here is a jpeg on how to install the new alternator belt.

There are several sizes as a function of model/year and alternators.

For our '86 P/N 999 192 176 50 9.5 X 710 W/2 shims between the pulley halves,
and the other four under the cup.

[rusnak]

On my 911, there are 4 bolt holes for the AC compressor mount, but only 3 of them have threads in them. I use a prybar to tighten the AC compressor belt rather than the adjusting bolt, which causes the compressor to rack at an angle.

A little trick to get the adjusting shims all under the cap washer: Tighten the nut finger tight, then use a screwdriver or similar to just push the washers in line while tightening the nut the rest of the way.

[byfdinky]

Hey Harry,

Just have him follow your lead and remove the A/C. Who needs it in the Rose City anyway!

[efhughes3]

Tell him to use the special spanner wrench to hold the fan pulley to remove the nut. It is unwise to try and wedge a wrench or screwdriver against a fan blade to hold the fan. Breaking a fan blade is a real possibility in that scenario.

[byfdinky]

On second thought, don't tell him to remove the A/C. He'll need it to keep it to help defog the windows.

The Glory Days: Jack Ramsey and Clyde the Glide!

[dshepp806]

Originally Posted by efhughes3

Tell him to use the special spanner wrench to hold the fan pulley to remove the nut. It is unwise to try and wedge a wrench or screwdriver against a fan blade to hold the fan. Breaking a fan blade is a real possibility in that scenario.

+1 on that one,....could be a big (costly) mistake for the unknowing........good point.....

Best,

Doyle

[HarryD]

Actually, I told him to come to this thread. I was being a pal to start it for him.

[jcsjcs]

1) Is there a trick to lining up the outer shims? An earlier post indicated that I could use a screwdriver to line up the outer shims after "finger tightening" the nut.

2) My old belt had all 6 shims on the outside and seems to not be OEM. My new belt seems VERY tight and is a Porsche Part. How many shims should I start with on the inside - or is this just a trial and error thing?

NOTE: My engine is out of the car - so I can't crank it to get everything inline.

[rusnak]

It's going to be trial and error, but try 3 on the inside, and 3 on the outside. You can do this with the engine out. Use the spanner that Ed refers to. Don't tighten the nut until the outer shims are lined up under the cup washer. If the shims, won't move, try loosening the nut a tad. The shims are captured by friction if you go finger tight first. Then, after tightening the nut a little, turn the fan with the spanner, and this will turn the pulley. Tighten the nut a little bit more, and turn. Tighten, turn, tighten. Now the fan belt is on and the pulley is tight. Check the belt deflection. You want about a 1/4". Adjust belt as needed, moving shims either out or in.

[jcsjcs]

I do have the spanner - and I guess I just need to be patient with the outside shims.

Will try and send an update.

[jcsjcs]

Thanks for the input. Just required some patience and doing exactly what Rusnak suggested - I tightened finger tight, backed off a bit, and then pushed the shims into place. I then tightened up and the shims aligned perfectly.

I actually took it apart again - just to be sure. At some point in the past, I did bend some of this shims - but this time worked perfectly.

Now that I can turn the engine via the fan nut, I am ready to adjust the valves.

Thanks for the help!

[Wayne 962]

It's very easy to mess up this belt installation. You should use a total of six shims at all times - if you think you need more or less, then you are installing it incorrectly. The shims prevent the nut from bottoming out on the shaft. If you don't put them on the outside, the nut will fall off.

Also driving the car with the fan belt off is a serious no-no. The temperature gauge on the dash is oil temp, not cylinder head temp. Without the fan running, your cylinder head temps will skyrocket immediately, and you will cook your heads and probably pull studs on your case. All this can happen without the oil temps rising significantly. Don't ever drive your car without the fan belt on - even for a mile or so.

Here's the scan from my 101 Projects Book:



-Wayne

[WPOZZZ]

And make sure the belt isn't pinched.

[TheGreg]

My issue isn't the Fan belt, nor the shims, that's clear. It's the damn AC compressor bolts. There are three that are easily reached with a socket - I got them loose easy enough. The fourth is stuck and solid and back under the hoses. I can't get a socket on it so open ended wrench only...and the head rounded on one of two access points. So...any advice on this?

I've sprayed some graphite on it and waiting for it to soak in a bit. But TheGreg is a bit frustrated that this "easy" job is throwing me a curve.

[wrxnofx]

Try a vice grips maybe. You just need to crack that bolt loose.

[gerber28]

Most of the shims on mine are outside and find it easier to wrap some painters tape to hold them in alignment, it peels off easy after you snug the nut tight.