So I replaced all my belts when I did the fan clutch this spring. All was good for about 1500 miles then it started squealing when above 3krpms when the ac is off. Doesn't squeal when the ac is on for whatever reason. Today I finally found the time to see what is going on. So I ran it for about 5 minutes with the belt squealing and then felt each belt to see which one was hot. It is the fan/alt/airpumb belt which I have a 4060560 belt on as the belt that I took off was a number that crossed to that from napa. Looking up the part based on year make and model though it comes back saying Excluding motorhome for that belt number but of course there isn't an alt. number offered anywhere I looked (ie rockauto, advance autoparts). Anyone know what gives? Oh and as for the squeal the belt is darn tight but I can probably get it a bit tighter. Just curious if there is a belt that is specific to the motorhome that is hd or something that I'm missing.

Benebob, if you find one let me know, I am going through them like Miller Lites. mine usually starts out with a squeal but when it gets worn that goes away.

SteveVW had a flat belt set up in his old Regal, I was going to convert to that also, until I checked out the replacement pulley(s) cost and a new harmonic balancer, alternator and water pump.

I think the only reason there is a Motorhome Chassis difference is length, funny I found the best belt to be the cheapo from Autozone, not a brand name or their Duralast brand the real cheapo comes in a yellow jacket just match the length of your old belt.. But the flat belt is optimum in IMHO .

If you make the conversion it might be craft beer you have to give up!

You have encountered a problem that surfaced for me also. The 86 454 was a transition with a flat multi-ribbed belt being used as well as other conventional V belts.

Mine had three V belts and a flat belt like yours. The AC did not work so I removed the pump, brackets and belt. Also removed both smog AIR pumps. (They didn't work any way)

I ended up with a V belt around the crank and the PS pump. Another V belt around crank, water pump, and PS pump. On the other side I had a flat belt around the crank, water pump, and alternator.

Like you, I found that no matter how tight I kept the flat belt, it would sometimes squeal when the alt was charging hard.

I have come to the conclusion that this belt setup was a GM flawed design. I have never seen any other multi-rib flat belt used except in a serpentine routing with a tensioner pulley on the slack side. Conventional V belts can tolerate a bit of slack and still grip the sides of the pulley, while the shallow multiribbed ones slip.

The layout on our early 454 had no tensioner. I had to adjust that belt all the time. I was planning to install a tensioner on the slack side where the air pump was. I discussed this with Alan, he may do it now.

Good luck.

My mistake Steve, I thought your flat belt was the answer, I think it needed a tensioner too.

I removed my AIR pumps and A/C long ago too.

My neighbor has a Toyota that has a flat belt sans tensioner, when it squeals I replace the belt form him.

quote:

Originally posted by Duane88:
My mistake Steve, I thought your flat belt was the answer, I think it needed a tensioner too.

I removed my AIR pumps and A/C long ago too.

It is a good start. With a good tensioner pulley it would prob never need attention again.

Yeah I have the same set up as Steve's 86. Vs for everything but the alt belt which is a flat 4 or 5 rib belt. I didn't have an issue with the old one over 15k that i put on it (plus what the PO did) The new one started slipping at 2000 miles or so. Tightened it up and for now it is quiet. I am sure it is too tight as I needed to use a 2" breaker bar.

I just have two V-belts, one runs the power steering pump and the other the alt, water pump and fan. I resized the belts to work without the A/C or AIR pumps. The harmonic balancer has two grooves, but they are different diameters so I can not use both belts to drive the fan and water pump it has two grooves but the same diameter, I wonder why the different belt speeds. I use the slower speed on the power steering pump.