Serpentine Belt Tensioner

[wsteele]

My belt tensioner and pulley is original and when I had my belt off for my recent alternator swap, I checked all the pulley's and the tensioner pulley bearing was a little rough.

I decided to go ahead and replace the tensioner assembly (versus just replacing the pulley), as I thought a new tensioner spring might be a good idea.

When I went to Rockauto, I just blindly ordered the "OE ACDelco" assembly, versus one of the aftermarket brands.

When I went to replace the tensioner today, I realized my old tensioner has 3 bolts holding it on and the new tensioner I got has just two bolts. I suspect this new style tensioner likely was introduced on my engine in later model years (maybe when they introduced VVT, etc.).

My question is, it looks like the two bolt pulley will go on in place the the three bolt, with the third bolt just going back in place without the tensioner flange under it.

Has anyone done this (replacing a three bolt with a two bolt tensioner) and also, will the short bolt on the bottom that is going back without the third point of the old tensioner being under it, going to be OK and not bottom out on anything?

 

[Foggy]

I've never seen one with 3 bolts.. All the ones I've done are 2 bolt dating
back to early C5 corvettes with LS1 engines...
As far as i know, they should just have 2 bolts that go into the water
pump housing...
So install it and roll on !!!

 

[wsteele]

I've never seen one with 3 bolts.. All the ones I've done are 2 bolt dating
back to early C5 corvettes with LS1 engines...
As far as i know, they should just have 2 bolts that go into the water
pump housing...
So install it and roll on !!!

Here is a picture of what I have now.

Here is a picture of the new one.

Guess I will give it a try.

 

[wsteele]

OK, just to close the loop.

I did install the new tensioner that came with two bolt mounting. I reinstalled the bottom bolt into the water pump housing (very slowly to make sure it didn't bottom and crack the pump housing), just in case down the road one of my heirs needs to install a tensioner and the parts store sells them a three bolt model.

I did do a little more research and it seems GM now lists the two bolt model as the correct part for my 2007 Yukon. Given I couldn't find an OE version of the three bolt (only aftermarket), I assume it has been retired by GM.

Everything seems to function as designed, with a little less rpm related noise coming from under the bonnet.

Anyway, this job was pretty labor non-intensive, so had time for a few shots.

Old tensioner in place:

Third bolt now unused, snug but not torqued.

Two tensioners, old style on bottom, new style on top.

 

[wsteele]

 

[wsteele]

PS - I would like to go on the record that I think the three point design is superior (stiffer) and that the two bolt design was an accounting decision versus and engineering decision.

 

[Joseph Garcia]

Thank you for sharing your experience. Our collective knowledge base has been increased, and I will definitely remember this, when I change out that tensioner on my 07.

 

[BG1988]

PS - I would like to go on the record that I think the three point design is superior (stiffer) and that the two bolt design was an accounting decision versus and engineering decision.

should have just swapped the pulley

 

[thompsoj22]

should have just swapped the pulley

Know that inside the OE tensioner is a "dampener design" which prevents belt slack as the pump cycles on/off. It wears also and is really a critical part of the design which the "CHINA CRAP" eliminates. Beware of the $11 autozone "DEAL".

 

[Foggy]

Yup. The tensioner part wears too , just like the belt and pulley bearings
I generally only use Gates stuff.. Not sure where it's made.
There are some very informative videos on gates/dayco/etc websites
that do a great job of explaining all this

 

[HD_LS]

I used to think Gates was good as well. I got a new POS Gates tensioner last year. Wouldn't recommend to anyone. Had to throw it out and buy an ACDelco 2 bolt one. Bought a number of Gates hoses that appeared to be crap quality as well, and went back and purchased OEM GM EPDM hoses instead; no comparison.

If you are into reliability, buy a billet aluminum pulley to go on your tensioner, from ebay.