Fan belt

Kevin Lynch

PCS Member
Today I started the motor on my 75 Lifeliner for the first time since the motor was rebuilt a year or so ago. It's still on a trailer but coming off and moving into a body shop. The car is missing one belt and I can't find it online and NAPA said it doesn't exist in their records. It connects the alternator, water pump, and fan.

Has anyone replaced one of these? I'd appreciate knowing where you got it and what the part number is. Thanks!!!!!
 
Paul should have those numbers we replaced all of them on his 69. but if you at a loss just run a 1/4 in rope around the pulleys and mark it were it goes back around. measure how long it is and go get a belt that long.
 
Thanks as usual Ed

Thanks Ed! I've got the "rope" and on the way to NAPA now.

Paul: any help you could provide would be great!
 
I meant to post yesterday but got sidetracked, I looked on my 75 and the belt for the 80A alternator is a 15515 so I would guess a few sizes larger for the bigger unit.
 
The original part number is 9433920 in Group 1.066. This is a 1/2 inch belt that is 57 1/2 inches long. The problem that you experience today, is that belts come only in 1 inch increments.

The common part numbers for a 57 inch belt are...

DAYCO Part # AP55 Gold Label Wrapped Industrial V-Belt; Outside Circumference: 57in; Top Width: .500in
Category: 12.7mm (1/2") Belt

DAYCO Part # AP56 Gold Label Wrapped Industrial V-Belt; Outside Circumference: 58in; Top Width: .500in
Category: 12.7mm (1/2") Belt

I would suggest going with the larger belt and seeing if you can get enough movement in the adjustment to make this belt tight. If not, then you are going to need the smaller belt, and it might be necessary to remove a part to get it on. I had this problem with my 1962 Chevrolet with the air conditioning belt. One size larger was too large, and one size smaller was too tight to get over the pulleys. I had to remove the air conditioning compressor, and mount the belt over the pulley, and then remount the air conditioning compressor. Once the belt had some wear on it, I was able to tighten it again, and all is well. You might be able to find another brand of belt that does come in the 1/2 inch increments, however, it might not be a wrapped belt like the one that I have shown above. These belts are available from www.RockAuto.com at reasonable prices.
I would also suggest your measuring as Ed has suggested to verify that the information in the parts book is correct. Here is the original post that Ed refers to my car...
 
Update... I finally found a correct belt for my Chevrolet, and I wrote the part number in the front of the factory service manual... Paul
 
belt mystery

My 69 MM is now at a new mechanic's. He told me today the belt pulleys don't seem to be in line. I showed him my 70 Superior and told him I knew the belt and pulley arrangements were not the same (the Superior has double belts on the power steering pump for example). I gave him a diagram one of you sent me last week. Is it me who has all these unique issues, or have any of you been through this? The mechanic wonders if something wasn't installed right - like the AIR pump which was put in last week. ????
 
Lets start off with the facts. It is a commercial chassis, and GM Cadillac Division built everything from the windshield pillars forward, and it doesn't make a difference what body builder built the body. The drivetrain is all the same from the tip of the crankshaft to the back of the differential housing. If the car had been crashed in the front, the pulleys might be wrong. The only way to know for certain is to remove them, and see if the pulley is stamped with a part number, and then I might be able to look up that part number and tell you what it is from. I have a problem with my Chevrolet with the belts, and it turned out that I had the wrong water pump pulley. Got the correct pulley, and no more problems.
 
Epilogue

Well yes, both motors are identical, except the 69 has the AIR pump. Both should have 5 belts, but the 69 has 3- comparing the two show that there should be double belts to the PS and generator...but there aren't yet. Thanks to all for chiming in....
 
Back
Top