2011 4Runner idler / tensioner pulley replacements

2011 4Runner idler / tensioner pulley replacements

Nothing used was sponsored. Everything we used we purchased.

About maybe 3 months before I decided to tear into this project. I was doing an oil change and some other oil change maintenance stuff like replacing the serpentine belt and what not. While I was replacing the belt, I was checking the bearings on the tensioner pulley and the idler pulleys. Some of the bearings have seen better days. One bearing was just stiff the another was loud and dry sounding when I spun them by hand. A very light groove was forming on the face of the pulleys as well. I will say around 150K miles on these pulleys. While researching the parts I needed I found a complete pulley kit on rockauto.com. I like replacements kits. Saves time on sourcing all the parts. GATES 90K39258 The kit was $281.89 on rockauto.com when I purchased the kit.

complete idler tension pulley gates 90k39258 kit


The kit included:

1 x Belt Tensioner (GATES 39258)

1 x Idler Pulley Lower (GATES 36174)

2 x Idler Pulleys Upper (GATES 36173)

1 x Belt (GATES K070846)



Just as a preventative maintenance measure it was time to replace them. If a pulley goes out then eats up a serpentine belt 100 miles away civilization, it is going to be tough to make a new serpentined belt work even if you had a replacement in your rig with that bad pulley. I definitely recommend having a back up serpentine belt is a good thing to carry on long desolate excursions.

Now run 3 months into the future to where I am pulling the front bumper off so I can paint it. I ran the bumper around for about a year on the truck as bare metal. One of the perks for living in the desert. I also planned on doing the pulleys at the same time. I figured it was a great time to replace the pulleys with the bumper out of the way.

5th gen 4runner bumper was already off

That is when I spotted this little tiny hitchhiking pebble in my pulley eating at my 3 month old belt.

tiny little pebble in my pulley eating up the new serpentine belt
ruined new serpintine belt 5th gen 4runner
before installation of pulley kit 5th gen 4runner
after pulley installation 5th gen 4runner