How to remove serpentine belt

Palmeroj · July 17, 2019

Hi.

I'm trying to replace the belt and having trouble finding the notch on the tensioner to attach a break out wrench or some other tool to release tension.

The vehicle is a 1996 GMC Suburban K2500 7.4 liter Vortex engine with AC and approximately 140K miles.

These are the best pictures I could manage given the tight clearance.

Here, the tensioner can be seen below the alternator.

Here are similar parts I found online, but not sure if they're the same exact part.

If anyone has worked on one of these, I'd appreciate some suggestions.

Lsgun1 · July 17, 2019

It's the pulley you pictured with the part number and yellow tag visible. Go right on the bolt holding the pulley on.

Palmeroj · July 17, 2019

Do you mean the center bolt in the middle of the pulley? Just turn it right (tighten it)?

DeePa · July 18, 2019

Move it away from the belt.

Id replace the tensioner pulley too.

Palmeroj · July 18, 2019

I tried tightening the center bolt on the pulley as suggested but this just tightens the bolt. I went as far as I could but afraid to break the bolt if I had kept going. By the way, turning it to the right (tightening it) is towards the belt. Seems this would add to the tension.

I then tried to the left (which is away from the belt) but this just loosens the bolt to the point where the pulley may fall off.

I then tried using my break out, long handle ratchet by bracing it against one of the other pulleys but this doesn't work either. That sucker just won't budge. I also don't think this is the right way to do it. There must be a pressure point or notch were it can be loosened.

By the way, this part seems to have been discontinued. There is a replacement on Amazon and eBay https://www.ebay.com/itm/Discontinued-GM-10237275-Replacement-Drive-Belt-Tensioner-7-4L-454-w-Smog-Pump-/332464494540

txab · July 18, 2019

Did you ever consider the tensioner is frozen in place? I've seen that. If so, remove pulley, then remove and replace assembly

Are you putting your wrench horizontally, at about the 9 o'clock position and turning (lifting) clockwise? Even the 8 o'clock pos.

txab · July 18, 2019

Btw, looks like Dorman makes a replacement. #419-126

Palmeroj · July 18, 2019

Definitely frozen in place as you suggested. Gave it a soaking in WD-40 and after working it back and forth, I was able to get minimum slack on the belt, enough to pull it out. However, when I release it, it does not return.

As Lsgun1 suggested, turning the center bolt to the right loosens the belt.

Definitely need a new tensioner. I'll look at the replacement you suggested.

Thank you all for your great help.

Jon