74 big block idler pulley with factory air.

[Charlied]

Want to replace idler pulley. Car has two belts. Original pulley about 1.5 inches wide, diameter 4 inches.Ordered “correct “ pulley from Rock Auto diameter right, width 1 inch, would work with single belt. Napa part same.
Any idea who might sell correct one ? Think part # is 3830 162, if I read my part book correctly.
Thanks

 

[pnora]

Want to replace idler pulley. Car has two belts. Original pulley about 1.5 inches wide, diameter 4 inches.Ordered “correct “ pulley from Rock Auto diameter right, width 1 inch, would work with single belt. Napa part same.
Any idea who might sell correct one ? Think part # is 3830 162, if I read my part book correctly.
Thanks

If its the water pump belt tensioner pulley you are talking about it is a single groove.

 

[Charlied]

If its the water pump belt tensioner pulley you are talking about it is a single groove.

Sorry, I wasn’t clear. The pulley keeps tension (downward)on the twin belts that run from the crank up to the A/C compressor, to the alternator and has no grooves. I think the idea was since it is a long run from A/C compressor to alternator to cut down on vibration and belt hop.
My concern is with the pulley slightly narrower,could a belt slide off. Maybe making a mountain out of a molehill here.
What do you think ?
Thanks for listening.

 

[pnora]

This would be your pulley. 1 inch wide is plenty for two belts. 1974 DODGE CORONET 6.6L 400cid V8 Idler Pulley | Shop Now at RockAuto

 

[Charlied]

This would be your pulley. 1 inch wide is plenty for two belts. 1974 DODGE CORONET 6.6L 400cid V8 Idler Pulley | Shop Now at RockAuto

Well, I bought that pulley from Rock Auto, doesn’t work, returned it. Checked around, NAPA, ADVANCE, the pulley they offer identical. What’s crazy all say correct for factory air, which is what I have, I don’t get it.
Maybe since I have dual pulley alternator has something to do with it.
If I get ambitious tomorrow will take a picture and send it you

 

[T2R9]

Can the bearing be pressed out and replaced? Just thinking out loud, 73 and up stuff gets weird. Kinda why I am using 72 and down pulleys on my 74.

 

[khryslerkid]

If it's just a bad bearing a lot of the time you can replace just that.

 

[pnora]

Well, I bought that pulley from Rock Auto, doesn’t work, returned it. Checked around, NAPA, ADVANCE, the pulley they offer identical. What’s crazy all say correct for factory air, which is what I have, I don’t get it.
Maybe since I have dual pulley alternator has something to do with it.
If I get ambitious tomorrow will take a picture and send it you

All factory a/c in that vintage had a dual groove alternator. Post some pictures.

 

[Charlied]

All factory a/c in that vintage had a dual groove alternator. Post some pictures.

OK,here are pics. BTW confident P/N is 3830162,haven’t found one.

 

[Charlied]

Can the bearing be pressed out and replaced? Just thinking out loud, 73 and up stuff gets weird. Kinda why I am using 72 and down pulleys on my 74.

Good thought, have to investigate, have to find some one to do it, way above skill level.attached some pics, believe P/N 3830162 . Thanks

 

[Charlied]

If it's just a bad bearing a lot of the time you can replace just that.

Good idea, have to search for some one who could it, don’t have a drill press and above skill level. Attached some pics of pulley, it’s really a tensioner.

 

[pnora]

That number is not available. Myself I would remove it and run without it. All the Chrysler cars in that year did not use it. Plus millions of others did not use that set up. No rhyme or reason. Or you can take it off and look for any numbers on the steel part along with a bearing number. With the bearing number you could possibly find a bearing and get it pressed in.

 

[Charlied]

That number is not available. Myself I would remove it and run without it. All the Chrysler cars in that year did not use it. Plus millions of others did not use that set up. No rhyme or reason. Or you can take it off and look for any numbers on the steel part along with a bearing number. With the bearing number you could possibly find a bearing and get it pressed in.

View attachment 1812276

Good logical approach
Thanks

 

[Sixpactogo]

My 78 440 didn't use that tensioner pulley either. Only had the alternator for adjuster.

 

[RJRENTON]

Good logical approach
Thanks

I concur.....run without the idler pulley. Older vehicles with A/C did not use this arrangement but a different water pump drive arrangement.....perhaps 1970 and older B and RB engines. The slight loss (~ 4° contact angle with compressor clutch drive sheave) and MIGHT require slightly shorter drive belts or perhaps the difference can be taken up by the alternator adjustment (greater or more travel) ....... just a thought....
BOB RENTON.