Toyota Yaris Forums - Ultimate Yaris Enthusiast Site


Go Back   Toyota Yaris Forums - Ultimate Yaris Enthusiast Site > Technical Forums > DIY / Maintenance / Service
  The Tire Rack

Thread Tools Display Modes
Old 08-25-2020, 11:53 PM   #1
Drives: 2010 Yaris 2 door hatchback
Join Date: Feb 2019
Location: Costa Mesa, CA
Posts: 9
Serpentine belt tension questions

The spec serpentine belt deflection for my 2010 two door Yaris hatchback is .43-.51 inches according to my 2010 Yaris Hatchback Factory Repair Manual. But the manual does not specify the amount of force to apply to the belt when measuring deflection.

The standard recommended belt deflection is 1/64" per inch of belt length. My serpentine belt is 10.5" between the centers of both pulleys. So the deflection should be 10.5x1/64=.16". But again, the amount of force applied to get 1/64" deflection per inch of belt length is never specified.

I have a belt tension measuring tool that measures deflection when 10 foot pounds of force is applied. How many inches of deflection would be in the specified range for my car with ten foot pounds of force applied?

Thanks for any replies.
Rob888 is offline   Reply With Quote
Old 08-26-2020, 09:03 AM   #2
Drives: 06 2ZR Turbo Yaris RS
Join Date: Aug 2017
Location: Beaver Harbour, New Brunswick, Canada
Posts: 2,148
Not sure why they call it a "V" belt, but this came from my service manual. I'm not positive that this is what you're looking for.


2006 Yaris 5 Door RS 2ZR-FE (2011 Corolla 1.8L) Swapped, Automatic, T-28 Turbocharged (8 psi), DIY W/M Injection, custom 3" cold air intake, custom 2.5" exhaust, TRD rear sway bar, Penguin Garage 13mm spacers (rear), custom Civic front lip, full repaint, Android 6.0 7" touchscreen, Rockford Fosgate speakers, tweeters, NVX underseat subwoofer
06YarisRS is offline   Reply With Quote
Old 08-26-2020, 09:53 AM   #3
WeeYari's Avatar
Drives: 06 Polar White 5dr, 13 Soul 4u
Join Date: Oct 2008
Location: Georgetown, Ontario, Canada
Posts: 5,382
A few years back Toyota issued a TSB addressing belt squeal. In it, the tension specs had been revised to reflect a higher degree of tension than previously specified. The TSB is on this site somewhere.
WeeYari is offline   Reply With Quote
Old 08-26-2020, 10:29 AM   #4
WeeYari's Avatar
Drives: 06 Polar White 5dr, 13 Soul 4u
Join Date: Oct 2008
Location: Georgetown, Ontario, Canada
Posts: 5,382
WeeYari is offline   Reply With Quote
Old 08-26-2020, 10:38 AM   #5
Leegamer's Avatar
Drives: 2008 Yaris HB 5-Speed
Join Date: Mar 2012
Location: Ashland, VA
Posts: 609
This is really the biggest issue with the yaris as far as I'm concerned. Fortunately it's pretty easy to tighten the belt once you've done it once.
I'm a hermit named Lee
Leegamer is offline   Reply With Quote
Old 08-26-2020, 07:29 PM   #6
ern-diz's Avatar
Drives: 2007 Liftback
Join Date: Sep 2007
Location: CA all day
Posts: 3,728
When we pulled my alternator off to check if it was still producing the right amount of buzz, we tension'd the serpentine belt with 2 or 3 good ugga duggas
On Instagram

On Wheelwell
ern-diz is online now   Reply With Quote
Old 09-09-2020, 11:50 AM   #7
Drives: 2010 yaris
Join Date: Jul 2020
Location: 75110
Posts: 4
my belt squeeked when i got my 2010 3dr.
i took off the alternator to find the tension arm takes the force for tension and alternator support and stabilizing. the 14mm bolt on the bottom of the alternator leaves the alternator loose when fully tightened. so it meant that the force goes entirely to the little arm. my arm had a nut tack welded on in the middle of the arm for some other use like a bypass pulley or something. upon deep inspection and removing the little arm the arm was cracked in the middle and the alternator was not stable. the arm would wiggle. the alternator would wiggle. the belt would squeak as sudden rpm changes occur. like everytime you go from AC off to AC on.

i welded the crack to make the arm solid again. all good. reinstalled

my advice on torque is everything you can possible muster with one arm. if or you are weak then both arms but you need a buddy to tighten bolt. get a gates belt. throw that thing on there. tighten it being careful of the VVT oil solonoid.
kd5oldx is offline   Reply With Quote
Old 09-12-2020, 01:14 PM   #8
andulong's Avatar
Drives: 2008 Hatch Red
Join Date: Apr 2012
Location: San Diego, CA
Posts: 64
When I replaced the belt in my "08 Yaris I read all the specs on tightening and then went to work. I soon realized that there was barely enough room to get the belt on let alone get any kind of tools in there to take a measurement. I tightened it until it felt right to me. Couple days went by and it started squealing on startup. Tightened it just a bit more and all good.
andulong is offline   Reply With Quote
Old 09-13-2020, 08:51 PM   #9
Drives: 2015Yaris, Son's car, 10 Prius
Join Date: May 2010
Location: Texas
Posts: 161
It also seems like the Yaris is picky about which belts that won't squeal. It seems like we he've had good luck only with the OEM.
alanwagen is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Determining proper tension for new serpentine belt RMcG DIY / Maintenance / Service 8 06-06-2018 12:31 AM
Which serpentine belt? courtartanis DIY / Maintenance / Service 0 11-30-2017 10:32 AM
Squeal from Engine after replacing Water Pump and Serpentine Belt vidfan DIY / Maintenance / Service 7 06-24-2014 10:41 AM
Lost Serpentine Belt NickNickNick DIY / Maintenance / Service 33 07-31-2011 12:28 PM
serpentine belt for 2007 yaris hatchback nikki9 DIY / Maintenance / Service 4 04-09-2011 09:22 AM

All times are GMT -4. The time now is 02:33 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.