Here is a DIY I created on changing the belt for a V6. Shouldn't take more than 10 mins, belt cost $35-$40.
http://www.toyota-4runner.org/4th-gen-t4rs/82482-diy-changing-serpentine-belts-v6-1gr-fe-4runners.html
The belt tensioner is spring-loaded so just release the tension, slip on the new belt, and the tensioner will return back to its normal position. I'll probably replace the tensioner once I hit 90K-100K.
My truck is a 2005 SE and I have about 64,000 miles on it. The belt started squeaking during start up a couple months ago and kept getting worse. Sorry, but I forgot to compare the old vs new belt. I won't be able to measure the tensioner for now since I'm bringing in my truck for warranty...
Here is a simple DIY on changing serpentine belts on the V6 (1GR-FE) 4Runners. I couldn’t find any DIY threads with pictures, so I decided to make one. It took me less than 10 minutes from start to finish, so anybody could do this with the basic tools. Hope this helps.
Tools needed:
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