1970 340 Serpentine belt questions

[Tim Chavez]

hey guys I need some help finding a new belt for the Charger. It currently has a serpentine but from what I’m reading that’s after market? It’s awfully loose (close to 1 inch of play) and cracked. and there is no tensioner to help out, just fan. alternator, crank and power steering pullleys. Currrent belt has the number 39455 and lists as a 63” v belt. What should I do to tighten it up? Is there a tensioner I can add? Should I look for a 62 inch belt instead? Thanks guys!

 

[5.7 hemi]

Well you don’t have a serpentine set up from factory, they were v belts and the tension was set with the alternator and power steering pump. A pic would help us understand what’s going on.

 

[Tim Chavez]

Well you don’t have a serpentine set up from factory, they were v belts and the tension was set with the alternator and power steering pump. A pic would help us understand what’s going on.

That’s why I’m here. I went to replace it at the part store and they brought up two belts, neither of which were near as long as the belt I pulled off. The charger currently only has one 63” long 1/2 inch wide belt running everything. The crank pulley still has both channels for two belts but only one belt is present and is routed through all 4 pulleys (crank,fan,alt and ps) I did some back dating on the belt and it’s a lawnmower belt so I’m kinda looking for advice. Find a comparable but slightly shorter belt to fix the issues or see what it would take to go back to two belts

 

[493 Mike]

hey guys I need some help finding a new belt for the Charger. It currently has a serpentine but from what I’m reading that’s after market? It’s awfully loose (close to 1 inch of play) and cracked. and there is no tensioner to help out, just fan. alternator, crank and power steering pullleys. Currrent belt has the number 39455 and lists as a 63” v belt. What should I do to tighten it up? Is there a tensioner I can add? Should I look for a 62 inch belt instead? Thanks guys!

It sounds like you have a fractional horse power v belt driving every thing. Not good. Too much load for one belt. Sounds like alternator or PS pump has been shifted to align with the drive groove. Look for spacers that do not look like OEM.
Mike

 

[Bill Monk]

Tim, a picture would be extremely helpful here. Going back to a stock setup is pretty straight forward

 

[Tim Chavez]

Tim, a picture would be extremely helpful here. Going back to a stock setup is pretty straight forward

Ok I just looked through and don’t have any good pics stored. I’ll take a few when I finish peddling tires today

 

[wyrmrider]

is fan reverse rotation?

 

[Tim Chavez]

is fan reverse rotation?

Never thought about it till you just said that!!! Yes it definitely is spinning counter clockwise. And pushing air out instead of sucking It in i bet!

 

[wyrmrider]

My magnum withthe flat serpentine drive spins "backward" but the fan is pitched "backward" also
It came with a 7 blade 3" pitch but service bulletin changed to 9 blade 2 1/2 inch pitch and raised the cut in point of the clutch from 185 to 195 degrees
early sounded like you were in a wind tunnel- later was quieter
my 6.0 late Chevy has 11 blade plastic fan
I'm going to see if it fits my mopar sometime

 

[Tim Chavez]

Well that’s out... the fan appears to be pitched backwards as well. Looks like there’s an extra channel on the alternator and the crank? What do you guys think?

 

[Tim Chavez]

Forgot one lol

 

[incinr8]

looks to be a V Belt, Not a serp. It also looks to be routed wrong. I think you need 2 V belts. One for the water pump, Alt and crank. And one for the PS Pump and crank.Looks to be a stock set up.

 

[5.7 hemi]

The fan looks to be pitched correctly also. You do need 2 belts. The alternator lower bracket is for adjustment and the power steering pump lower bracket is for adjustment. So I’d suggest you start with factory size belts, alternator and power steering and loosen the adjustments on both, install the belts and pull the slack out of the belts, tighten the bolts and burn rubber......or go cruising.

 

[wyrmrider]

Well that was interesting
done something similar when lost a belt out in the middle of nowhere
looks like you would get water pump/ fan slip with that little belt/ pulley wrap
fanclutch would help what fits?

 

[493 Mike]

The water pump pulley may have been changed to make one belt alignment possible. Cruise this site for small block belt setups.
Mike

 

[Tim Chavez]

Well that was interesting
done something similar when lost a belt out in the middle of nowhere
looks like you would get water pump/ fan slip with that little belt/ pulley wrap
fanclutch would help what fits?

It’s real bad haha that’s actually what made me look at this in the first place. It hasn’t been a runner in some time (owned since I was 15 in now 29) and when I was sorting the timing out and finally got it to run I readized the fan wasn’t turning second look the belt wasn’t moving either haha. The alt and ps look like they are maxed out as it is so I went ahead and got the stock v belt setup. We will see if it all lines up.

 

[Bill Monk]

Agreed on above statements, you need two belts. Not a sepentine setup

 

[Tim Chavez]

Alrighty gents I’m pretty sure I shouldn’t have to pull my fan pulls to install the ps belt... any thoughts?

 

[5.7 hemi]

That is correct.

 

[Tim Chavez]

Welp wasn’t a complete waste atleadt I got the tie rod off!