autozone alternator v-belt (5s-fe) getting loose every few weeks

[fenixus]

do you recommend running only good accessory belts like OEM, gates, good year or so ?

i have some cheap alternator v-belt and this crap gets loosened down to 90-100lbs every few weeks and i keep tightening it up to 120lbs. i'm afraid it will break at some point. it's about 8 months old.

problem is that when it gets loosened i get some vibrations noise at 1800-2300rpm range and i hear it often when accelerating mildly.
when tightened up some less noise appears a little at around 2300rpm only.

[chronoti]

i run dayco, i had dayco from factory (yes stamped toyota and dayco) and i still use dayco, only once had a problem with it where i shot the engine in to the red and shredded the p/s belt.

[fenixus]

i think i will go with the oem (p/n 90080-91122-83), it's just $8.76 shipped from toyotapartsoutlet.com while dayco poly-rib v-belt is at $21.99 from advace auto parts.

[fenixus]

old aftermarket (no brand markings) belt kept getting longer. last time i checked it was sitting at 90lbs again. replaced that crap with OEM part from dealer. when i compared old and new, the old one was about 1 inch longer.
tightened new one to around 170lbs and after driving for an hour it sits at ~120lbs, will double check later.

[carsrus]

Are you sure your not overtightening the belt and making is stretch? 120lbs sounds like way overkill.

On the 5sfe my trick is to tighten it untill its pretty snug. Start the car and rev it and look for flex belt the alt and crank by looking at an angle. Tighten it just enough so that flex is out of it when its revved. Or look at the tensioner bolt and tighten it down to where the threads are clean.

I wouldn't use or trust a torque wrench on a drive belt.

[fenixus]

Originally Posted by carsrus

Are you sure your not overtightening the belt and making is stretch? 120lbs sounds like way overkill.

On the 5sfe my trick is to tighten it untill its pretty snug. Start the car and rev it and look for flex belt the alt and crank by looking at an angle. Tighten it just enough so that flex is out of it when its revved. Or look at the tensioner bolt and tighten it down to where the threads are clean.

I wouldn't use or trust a torque wrench on a drive belt.

no, i'm positive.
toyota spec for used (older than 10 minutes of running) alternator belt is 100-120lbs.
toyota spec for new (used for less than 10 minutes) belt is 120-190lbs. i'm checking it with Krikit II gauge.
specs are per Haynes.

[JohnGD]

In general, use about 25% more than running tension initially. So 150 lbs should be sufficient given the 120 lb target.

When a new belt adjusts and sits, it might loose a little bit of tension after the initial adjustment. But it should remain fairly constant for the expected life of the belt.

At the end of life you may notice the rapid tension loss like you saw with the no-name belt.

Did you get a Toyota-branded Dayco, Mitsuboshi, or Bando? Just wondering. I stick with Gates belts and hoses myself.

Originally Posted by fenixus

no, i'm positive.
toyota spec for used (older than 10 minutes of running) alternator belt is 100-120lbs.
toyota spec for new (used for less than 10 minutes) belt is 120-190lbs. i'm checking it with Krikit II gauge.
specs are per Haynes.

[fenixus]

the new one has green TOYOTA imprinted on it and says Made in USA. i haven't noticed any other brands, may need to look again. will measure it again tomorrow to see if it holds. after second thoughts i think it was reading 110lbs actually, sorry i am a little unsure, but i think it was 110 (from initial 170) after all.
though the initial measurement was done right after tightening the pivot and lock bolts, before engine cranked, so it might be off a little...

[JohnGD]

Right, you'll have to turn it a rev to even things out.

Originally Posted by fenixus

though the initial measurement was done right after tightening the pivot and lock bolts, before engine cranked, so it might be off a little...

[fenixus]

i'm sorry, double checked the belt again, it says Bando.

double checked the tension and today i was getting 140-160lbs or 120lbs when using different gauge orientation ... LOL
anyways loosened the belt by one counter clock wise turn of adjusting screw. i was getting ~120lbs after that. initial 170 might have been too high. now corrected.

[JohnGD]

The Krikit-II type does need some practice, but after a while, taking a few measurements in the middle of the longest stretch should yield consistent values. The key is applying pressure only on the pad, but I'll have to say it's easy to be off in cramped spaces and otherwise make the gauge tilt a slight bit (give wrong readings).

Yeah, Bando seems to be the in brand for Toyota drive belts these days, over Dayco Mitsuboshi and Goodyear. One other TN member got a Mitsuboshi timing belt last couple of weeks, this seems still a fave.

Next time try about 140 for the Alt/AC belt and about 100-110 for the PS belt. Rotate the crank 1-2 rev then Krikit after adjustment. That way after running 5+ minutes the tension should fall into about the middle of the "used belt" range automatically, and you wouldn't need to "re-adjust". Check the tension once or twice a year. It shouldn't change much if at all under 60K miles.

It's another reason I like automatic belt tensioners instead of these jack screws and slide rails.

Originally Posted by fenixus

i'm sorry, double checked the belt again, it says Bando.

double checked the tension and today i was getting 140-160lbs or 120lbs when using different gauge orientation ... LOL
anyways loosened the belt by one counter clock wise turn of adjusting screw. i was getting ~120lbs after that. initial 170 might have been too high. now corrected.

[fenixus]

thanks.

P/S belt is good year and is 6 month old. krikit showed good tension on it. seemed like in the middle of spec.
i will re-measure alt belt again soon to make sure. i think key to success is taking measurement every time in same spot. i have one when i touch with my left hand something plastic (a clip it was) to hold gauge steady by sides and then i use right hand finger to press on it.

when i use one hand only then i sometimes slide it off the belt. i might finally make use of that rubber "finger holder" on gauge for one-finger use

reason why i took 170 for initial setting was that it was only half way through "shiny" adjusting screw threads after former aftermarket belt. you can now imagine how tight it was set and still showing loose tension.