Alternator V Belt Will not Stay on when tight

[85indybronco]

Hi,

New to the forums and have been searching the threads for a while but I can't find anything that deals with this specifically. I have a 1985 bronco with a 302, Fuel Injected no AC. Went to replace the alternator V belt ( no serpentine belt on this) with a cogged V belt from autozone. Tightened it until it had less than a half inch of play. Belt continues to pop off as soon as engine is started. Just walks right off. I don't think the cogged belt sits down in the pulley well enough but that is all I can find. It just seems too wide. Even the motorcraft belts appear to be cogged now. Any ideas on why this belt will not stay on? Everything seems lined up, but somehow the belt just walks right off. Thanks in advance and sorry if there is a similar post somewhere. Everyone seems to have serpentine belts.

 

[Bully Bob]

That is odd...

Sounds like it is the wrong width. As the belt sits in the grove...it shouldn't stick out above the pully edges except maybe slightly.

The coggs wouldn't make a difference..., they just allow it to flex easier.

 

[Krafty]

yes I would say you have a width issue, also how is your alternator for alignment with your crank pulley? it shouldn't be an issue but its worth looking at. if you can take in your old belt and make sure you can find a narrower vbelt,

 

[85indybronco]

Ok thanks guys. It doesn't seem to fit as deep on the pulley as the original belt so I'm assuming the belt us an issue. Alignment seems ok between the crank and the alt pulley. I will check with ford for a better fitting belt.

 

[miesk5]

yo Indy,

Good idea on using a Ford MC Belt!

Other belt brands that are of high quality and could be Ford's OEM supplier (@ least in past they were..)

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Good Year

Some search results for your year; go thru the drill to see Images, sizes, Length

top Width in inches...& other makes... BUYERS GUIDE (other makes & models this belt or other GY Part shown is used on)...

 

great to print out & save in the Bronci for the GY parts for the Bronco to use in case of repairs while on road and use at a yard!

49043 A/C Drive Belt Idler Pulley 1

Idler Pulley - AC; Idler Pulley; Factory AC

Goodyear

63726 Engine Coolant By-Pass Hose 1

Molded; By-Pass; Cut to Fit

Goodyear

AIR PUMP

15325 Accessory Drive Belt 1

V-Belt; w/ 70 or 100 Amp Alt.

Goodyear

ALTERNATOR

15382 Accessory Drive Belt 1

V-Belt; W/70A or 100A Alt

Goodyear

ALTERNATOR

15386 Accessory Drive Belt 1

V-Belt; W/40, 60A Alt

Goodyear

FAN

17474 Accessory Drive Belt 1

V-Belt; Exc AC

Goodyear

FAN AND POWER STEERING

17521 Accessory Drive Belt 1

V-Belt; Exc AC

Goodyear

HEATER TO THERMOSTAT

65004 HVAC Heater Hose 1

5/8 " x 4'

Goodyear

HEATER TO WATER PUMP

65004 HVAC Heater Hose 1

5/8 " x 4'

Goodyear

LOWER

61105 Radiator Coolant Hose 1

Curved

Goodyear

TEE TO WATER PUMP

64314 HVAC Heater Hose 1

Goodyear

UPPER

61367 Radiator Coolant Hose 1

Curved

 

[85indybronco]

Thanks miesk5, good info

 

[nelbur]

I wonder if you don't have a miss-matched set up, because Ford introduced the EFI in the '86 bronco, not '85. That set up had two pulleys on the alternator, with the rear pulley lined up with the rear pulley on the crank. The outer alt. pulley ran the air pump above it. If that sounds like your set up, buy the alternator belt for an '86 302 EFI.

 

[85indybronco]

I wonder if you don't have a miss-matched set up, because Ford introduced the EFI in the '86 bronco, not '85. That set up had two pulleys on the alternator, with the rear pulley lined up with the rear pulley on the crank. The outer alt. pulley ran the air pump above it. If that sounds like your set up, buy the alternator belt for an '86 302 EFI.

That is my set up exactly, although the smog pump doesn't have a belt on it anymore. I thought 85 year was the first year for EFI, but only some models. Even at autozone it has you specify the 302 5.0 liter with FI but who knows. Anyway, my father in law picked one up at Oreily parts after explaining to them the problem. ( They first brought out the wider cogged belt) . Belt went on with no problem and works great. Thanks for all the help. Still wondering why mine is set up like an 86? Does anyone know when they went to a serpentine belt?