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Arench, Master Technician
Category: RV
Satisfied Customers: 1490
Experience:  30-years experience auto and truck repair.
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I have a 1984 Chevrolet 454 Engine in my RV and it continually

Customer Question

I have a 1984 Chevrolet 454 Engine in my RV and it continually throws the alternator belt. I have changed the alternator as well as the belts yet it continually throws the grooved alternator belt. I would appreciate your recommendations
Submitted: 8 years ago.
Category: RV
Expert:  Arench replied 8 years ago.

Greetings from Mikey at Just Answer!

Let me see if I can provide some helpful ideas with this belt problem.


I have seen this before when a fan clutch is locked. If the fan load is too high due to a faulty fan clutch, this will trouble the belt. If you hear the fan roaring when the engine is reved up when hot the fan clutch may be bad. With the engine hot and turned off you should be able to grab the fan and turn it by hand easily.


Contaminants on the belt is another common cause of belt failure. Leaking front crankshaft seal, coolant leak, leaking power steering or power brake unit, leaking master cylinder. Fix all leaks because belts can not tolerate contamination.


Alternators are not designed to charge dead batteries. If you have to jump start your RV often due to dead battery and then make the alternator charge a dead battery you will eat up belts. Repair battery draw down faults or install battery disconnect switch. Replace battery if it does not hold a charge.


Wobbly pulleys due to physical damage or faulty water pump causing pulley to wobble will make the belt come off. Remove belt and check water pump turns freely and shaft is not loose.


Pulleys out of alignment due to wrong parts, or improperly installed parts. Belts must travel in perfect alignment. Visually inspect belt alignment, use a ruler across pulleys to check alignment.


Use high quality belts. like Gates, Dayco, Napa, Carquest. Some brands of fan belts on the market are poorly made, make sure you're getting the best.


Be sure belts are properly tightened. Recheck belt tightness after a few hours of use after installing a new belt.











Customer: replied 8 years ago.
If it where the water pump wouldnt the other belt. A/C also break/overheat as there are three belts on this unit and only tha alternator belt fails
Expert:  Arench replied 8 years ago.

You can have one belt on a common pulley experience problems when other ones don't.


Belt load, and distance traveled comes into play. There is a long distance between the alternator and the crankshaft pulley on one side.


When a belt on a common pulley travels a long distance with nothing touching it, it can start flapping and jump ship.


Careful inspection of all elemenets listed above should reveal your problem.




Customer: replied 8 years ago.
I will carefully check the information provided and should your input be affirmative, I will gladly pay for your services
Expert:  Arench replied 8 years ago.

Groovy! Good luck!



Customer: replied 8 years ago.
I havent performed all the recommendations which you suggested due to my present physical disability, however I plan to perform alignment and pulley inspections soon. I have researched this isue and apparently it is not unusual with the 454. One source suggetsed that GREEN BELTs are installed which are used on Farm and Lawn equipment as they apparently do not stretch and are NOT cogged belts. I am searching for these deep groove non cogged "Green Belts" to replace the existing AC Delco belt # XXXXX which dimensions are 13/32 X 50 1/8" as well as the Gates XL Belt # XXXXX which dimensions are 13/32 X 59 1/8" which have resolved the problem using a NON COGGED "Green Belt" If you are aware of where I may be able to purchase "Non Cogged, Green Belts" as replacement belts I would appreciate being avised and I might suggest that this remedy may help others experiencing similar problems
Expert:  Arench replied 8 years ago.

The green belts you are talking about are made by Gates and they are called Fleetrunner Heavy Duty Belts. They are made for fleet trucks with extra high heat capabilities. These belts will ride a little higher in the pulley because they are slightly larger width being a true 1/2-inch belt, so you have to size up one size from your current belts.


Your 15495 belt would take a 9500HD Gates or a 259500HD NAPA.

Your 7585 belt would take a 9600HD Gates or a 259600HD NAPA.


As for where you can buy them, a truck parts place or a NAPA store. Most places do not carry these belts on the shelf so you have to order them and wait a day.


If you want to buy them on the net, you can order them from just use the gates numbers listed above.