Very Basic Question: Idler Pulley Differences - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cebra · 03-27-2019, 10:30 AM

I bought an idler pulley from rock auto but it is quite different than the ACDelco one and the outside "cup" does not work with it but the small inside one does. Do I just tighten the bolt right against the bearing on this and use the inside cup only? It just seems odd to me the stock one comes with a "cup" on the outside and this one is very different. This may be a really dumb question but I don't want to break a belt on the road. Thanks. Pics below of ACDelco vs what I ordered...both are idler pulleys per rock auto.

**Wgesnerjr** · 03-28-2019, 06:11 AM

I have both of these on my 2003 5.3 engine. one is an idler pulley, one is a tensioner pulley. Advance did the same thing to me, wrong pulley when I got it home. try searching "tensioner pulley" or "belt tensioner pulley" and see what you get.

cebra · 03-28-2019, 08:25 AM

Quote:

Originally Posted by Wgesnerjr

I have both of these on my 2003 5.3 engine. one is an idler pulley, one is a tensioner pulley. Advance did the same thing to me, wrong pulley when I got it home. try searching "tensioner pulley" or "belt tensioner pulley" and see what you get.

I think you are right, it looks just like the tensioner pulley...rock auto screwed that one up.

ls1nova71 · 03-28-2019, 09:26 AM

The tensioner pulley should be ribbed.

**Wgesnerjr** · 03-28-2019, 09:54 AM

Good luck getting Rock Auto to take it back or refund you. I once received 2 LH Brake hoses for a project. Finally threw it out after many frustrating discussions with them. Bought it locally to be sure I got the right part.

cebra · 03-28-2019, 10:25 AM

I ordered a new one...it was only like $10 so I will just hold onto it in my spare parts bin. I am glad I asked before I assumed the design had just changed. It is literally on my motor now so I need to replace it before I start it up...that could have been a disaster and a face palm moment.

**Wgesnerjr** · 03-28-2019, 10:31 AM

Yeah, like you, I never realized there was a second pulley until the mix up at advance. I did try and install it in the wrong place but it hit the idler and would not turn. That was when I found it other one. wound up installing both since they are so cheap. Much quieter now.

03-27-2019, 10:30 AM	#1
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Very Basic Question: Idler Pulley Differences I bought an idler pulley from rock auto but it is quite different than the ACDelco one and the outside "cup" does not work with it but the small inside one does. Do I just tighten the bolt right against the bearing on this and use the inside cup only? It just seems odd to me the stock one comes with a "cup" on the outside and this one is very different. This may be a really dumb question but I don't want to break a belt on the road. Thanks. Pics below of ACDelco vs what I ordered...both are idler pulleys per rock auto. Attached Images __________________ My Daily Driver Build: http://67-72chevytrucks.com/vboard/s...d.php?t=755668

03-28-2019, 06:11 AM	#2
Wgesnerjr Senior Member Join Date: Jun 2015 Location: Atlanta, GA. Posts: 737	Re: Very Basic Question: Idler Pulley Differences I have both of these on my 2003 5.3 engine. one is an idler pulley, one is a tensioner pulley. Advance did the same thing to me, wrong pulley when I got it home. try searching "tensioner pulley" or "belt tensioner pulley" and see what you get. __________________ Jay Gesner Atlanta, GA 1985 C10 Long Bed 4X2 LS 5.3, 4L60E Father/Daughter Project

03-28-2019, 09:26 AM	#4
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: Very Basic Question: Idler Pulley Differences The tensioner pulley should be ribbed. __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

03-28-2019, 09:54 AM	#5
Wgesnerjr Senior Member Join Date: Jun 2015 Location: Atlanta, GA. Posts: 737	Re: Very Basic Question: Idler Pulley Differences Good luck getting Rock Auto to take it back or refund you. I once received 2 LH Brake hoses for a project. Finally threw it out after many frustrating discussions with them. Bought it locally to be sure I got the right part. __________________ Jay Gesner Atlanta, GA 1985 C10 Long Bed 4X2 LS 5.3, 4L60E Father/Daughter Project

03-28-2019, 10:25 AM	#6
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Re: Very Basic Question: Idler Pulley Differences I ordered a new one...it was only like $10 so I will just hold onto it in my spare parts bin. I am glad I asked before I assumed the design had just changed. It is literally on my motor now so I need to replace it before I start it up...that could have been a disaster and a face palm moment. __________________ My Daily Driver Build: http://67-72chevytrucks.com/vboard/s...d.php?t=755668

03-28-2019, 10:31 AM	#7
Wgesnerjr Senior Member Join Date: Jun 2015 Location: Atlanta, GA. Posts: 737	Re: Very Basic Question: Idler Pulley Differences Yeah, like you, I never realized there was a second pulley until the mix up at advance. I did try and install it in the wrong place but it hit the idler and would not turn. That was when I found it other one. wound up installing both since they are so cheap. Much quieter now. __________________ Jay Gesner Atlanta, GA 1985 C10 Long Bed 4X2 LS 5.3, 4L60E Father/Daughter Project



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