How do I change the belts on my class A Chevy

I have a 89 Winnebago with a Chevy 454 carburated motor. Heres the story. Havent had it too long. It has always made a very loud "fan noise" that would cycle on and off. Just yesterday there was a very loud belt squeal then the "fan noise" got incredibly loud then I heard a belt break and the fan noise stopped and I then pulled off the road to discover the flat belt that drives the alternator was broken.

Does any one know where I can go to get the procedure steps or give the procedure to change this belt. Also, what other components does this belt drive. I was able to limp it home on battery power alone and it ran fine and did not over heat.

What component was making such loud noises?

This looks like a real challenge to get to these belts. Ive heard talk that my water pump is probably bad too.

Please help!! :question:


Senior Member
How do I change the belts on my class A Chevy

I'd send Winnebago an email and ask them for the procedures to change the belts. I, too, have a 89 Winn Chieftain and have contacted them several times for help/guidance and they have always came through with flying colors for me (water system diagram, electrical diagram, hitch electrical connections diagram, etc., etc.). I think the loud fan noise you hear is normal....kind of sounds like a jet engine firing up for a little bit. I can't remember what the Winn dealer told me, but they said it was normal, so I have not worried about it. You can check your water pump while your replacing the belt....see if fan wiggles. I have two fans in the front between the firewall and the I guess y ou have the same. I've got 12,000 miles on mine and the only real problem I have had is the brakes squealing when they get hot in stop/go traffic and some problems with the hot water tank (Atwood).
Bye the way, welcome to the forum. :)
How do I change the belts on my class A Chevy

That noise sounds like the fan clutch which is typical for that engine. The 454 is famous for fan clutch failures, cracked exhaust manifolds from heat, etc. I was never happier than when I got rid of my Class A with the 454 and traded for a unit with a V-10. Archer gave you some good advice as Winnebago factory customer service is extremely helpful with problems.
How do I change the belts on my class A Chevy

The belt is driven by the crank pulley at the bottom and goes around the waterpump (with fan) and alternator. Loosen two bolts (maybe three) on the alternator. One will be a long bolt throught the bottom and the alternator pivots on this bolt. There will be a short bolt through a slotted bracket on top. Loosen this one so the alternator will "swing" through a small arc. Loop the new belt over the fan and into all three pulleys. Use some kind of leverage to swing the alternator putting tension on the belt. Snug the alternator bolts back up and fire her up. You will still hear the fan cycle. Check your running voltage. Should be between 14 and 15 volts. I've done this one on the road! Good luck.
How do I change the belts on my class A Chevy

Your "fan noise" is the two-speed fan clutch on the Water pump shaft..There is a small "vane" on the fan hub, which is temp. sensitive. The fan is normally "free wheeling" : driven only by a slight amount of friction between it and the shaft.--As the Radiator heats up,( 125-135 deg.) the small vane slides open, and allows a small reservoir of oil to fill the space between the outside of the clutch and the shaft, effectively locking them together. The fan then speeds up to match the Water pump speed (speed of the shaft)--This is roughly twice the "free wheeling" speed..-This gives you the "jet engine sound"-- when it cools down a bit, the clutch "lets go" and the fan slows down a bit...You will hear it cycle on and off as it does--Enjoy the sound, embrace it, it will make you free,--a miracle of engineering, Vive La 454!!