throwing belt?

[haywire4130]

i have been having problems with my car throwing the belt. quick history: when i first built the motor i installed a dayco belt that was listed wrong in the catalog, ended up being too long and made the knocking/chirping sound and shredded itself to pieces the first time i leaned on it, which destroyed my hood liner and the wires to my iat sensor. with help from this board i switched to the goodyear 4060635 which worked great for a couple months but now it comes off when i lift at like 5k rpm or so. (what i'm picturing is the belt is stretching out under rapid acceleration and the tensioner isnt taking up the slack quick enough when i let off. at least it doesnt come apart like the dayco did, but its frustrating to smoke someone out of a stoplight only to have to pull over and put my belt back on, not to mention the lack of brakes because i'm running hydroboost. is there a measurement like with a spring scale or torque wrench to test the tensioner to verify it before i plop down the huge cash for a new one? also, i am running an a/c bypass which is the same diameter as the stock a/c compressor. i know a lot of people run the s-10 bypass pulley, which is a little larger diameter (like 3/8"). i bought both, should i try the larger pulley to put a little more load on the tensioner? has anyone else had this problem?

 

[scgnx2]

Years back, my GN was tossing belts and chewing them up.
It turned out that the AC compressor was loose and under load
would pivot and derail the belt. I see you have an AC bypass pulley.
Check the alignment of the pulleys...It cost me a hoodliner and 3 belts
before I figured it out..

 

[haywire4130]

hahaha i have the same invested so far, 1 hoodliner and 3 belts... im 75% sure my tensioner is weak but i figured i'd post and see if anyone had any info i didnt think of. the alignment is spot-on. i actually had to shim the bypass pulley out about 3/16" to get it right. i'm almost thinking about machining a new p/s pump pulley with tall ribs on the edges to keep the belt on if i cant figure this out, as im pretty sure that s where it is coming off

 

[dsapper]

I had an issue with jumping the belts on a different car. I bought the gatorbelt for it and never had the issue again. Not saying that the belt itself is your issue but if you need to buy another one I'd go that route

 

[TurboDave]

I just checked my tensioner, and it shows about 31-32 ft/lbs. on the torque wrench to pull it up well off the belt. Somewhat less to just move it a little.

 

[haywire4130]

thats the first thing i did, i really like the quality of the gatorback belt and i ordered 3 of them to have a couple around while i sort the issue out since nobody near me stocks them. the first time it threw the goodyear i tried swapping on a new one and it did the same thing. i suppose i should have mentioned that. it's funny how i can have such a fast street car and a piddly belt problem is holding me back hahaha

 

[haywire4130]

I just checked my tensioner, and it shows about 31-32 ft/lbs. on the torque wrench to pull it up well off the belt. Somewhat less to just move it a little.

wow, thanks for taking the time to do that! im gonna hafta dig out my beam-type torque wrench to check mine against your numbers, i only have the click ones at my disposal

 

[TurboDave]

That's what I used was a click type. Just kept going up in torque until it stopped clicking.

 

[87gninpa]

I used the 63.5" Goodyear belt for a few years and never really had a problem, but the tensioner wouldnt stop chirping. Got a 63.0" belt from the parts store just to see if it would help and now its quiet as a mouse. Might want to give that a shot. A lot of other guys use 63.0" belts with no problem as well.

 

[haywire4130]

maybe i'll try the larger bypass pulley since it will basically do the same thing as a shorter belt (since i have 3 of these belts now hahaha) i still have to check my tensioner with a torque wrench, waiting for the rain to stop

 

[TurboTnZ06]

Check to make sure the 2 power steering pump bolts haven't come loose. Mine did at the track. Made a helluva noise at the track and on the way home. Got home and the pump literally about fell off. Chomped the belt all to pieces. Took out my maf hose and upper radiator hose. Check your radiator hose for slices too!!!!!!!

 

[haywire4130]

well i checked the tensioner with a torque wrench against the numbers above, it clicked at 30 ft/lbs at about 3/4 travel, so it seems good. i'm gonna dig out that larger pulley and hope for the best. thanks all for the replies

 

[BGNeXtreem]

Mine was doing the same thing years ago turned out the long stud the ac compressor goes on was broke letting the compressor move changed the stud an all was well

 

[haywire4130]

Im not running a/c but ill check the stud thats holding the bypass when I check the p/s pump bolts, forgot to do that while I was under the hood this weekend. Heres hopin

 

[salvageV6]

Check for loose accessories.

Ditto for me with one loose and one broken power steering bolt.

 

[imjoesnuffy]

Check to make sure the pullies are lined up. With the AC delete pulley I was having the same issue. Looking at it from the side it appeared the tensioner was sitting back a little closer (1/8") to the firewall than all the other pullies. I used a few washers to shim it up and get them all back in line. No problems since.