okay let's have it ; who's using what belt with their 15% pulley? i want to know who makes the best belt out there. i'm running a 15% pulley with 63000 mls. on my original belt (yes it's slipping a bit) and want to put the best possible belt and tensioner stop on there before winter comes and it's too cold to work on my hot rod (cause my kids' 68 mustang is taking up my garage) . anxiously awaiting your replies lol . really.

 

I don't know how much difference the brand makes, but I have seen a post by a long time and experienced NAM member (MSFITOY) which recommended "Gatorback" belts.

I think the condition is more important than the brand, but some probably have favorites. Just stay away from stuff that is exceptionally cheap. The install instruction I got with my Alta 15% pulley specified to install a new (stock length) belt with the pulley if there was over 30,000 miles on the existing one!!! So, I think it's got to be a MUST at 60,000.

In addition I just read a couple of horror stories right here on NAM, in THIS VERY FORUM, about crank pulleys coming apart , with some uncertainty as to the cause, though one of the victims did say his belt HAD BEEN SQUEALING (read, "slipping") just before the problem occurred.

Better change it quick, dude.:impatient

Happy motoring.

 

i've heard countless times that the Goodyear Gatorbacks are the best, and that'll be my next belt....i could chase down the part number if you'd like

 

X2.

Have not used them, as I just had my belt changed right before I did my pulley to a OEM belt again (free, can't complain!) but when it wears I'll be going Gatorback!

-Cody

 

75,000 miles, 2 OEM belts. Never had a problem.

dan

 

just watch out when u install the gator back..
because if u align it a bit off, they tend to jump off and strip themselves..
I have seen 2 from local.. (including me!!)

 

Stock work or NAPA 25-060539 The Napa belt is about 1\2" smaller than stock.

 

I for one would like that number. Since installing my 15% alta pulley I've been using the oem belt used with the Works pkg with it's slightly less than 15% pulley, and using the 30 K interval .I do have a problem that I can't nail down which is the sound of a flock of birds under my hood for the first few minutes of warm up(loudest at idle).........even with a brand new belt.Goes away once warmed up.????? Off topic(maybe), but I also have a very high pitched tone at highway speeds, sounds like a moog synthesizer at the uppermost realm of what a human being can hear and varies with speed.It's been suggested that this is also belt related , but also something to do with the throttle body. anyone else get this?
Jock

 

GTR-4060547 is too long for 15% and 2% crank:impatient
Going to try GTR-4060537...

 

whoa....careful. That squealing noise is sometimes a crank pulley coming loose. I'd get that checked ASAP !

probably what people are talking about with the throttle body is if you have an aftermarkey intake, like an alta CAI, you can here air squeak past the throttle body butterfly at light throttle depression. It happens on highways often. This is probably what you're experience with your second problem. Next time it does it, floor the throttle, and if it goes away and is replaced with a whine , then its completely normal.

I'll go and check the part number....

 

Goodyear Gatorback #4060537 (#6PK1365)

effective length of 53.75"

 

how does an OEM crank pulley attach that it can come loose? Now you got me scared! this has been going on for months.I always thought it was possibly due to a failure of the bearing in the belt tensioner idle pulley and I just got a belt tension tool and was going to take the tensioner out and have a look .I contacted Cosworth in England a while back and corresponded with a guy named Mick about their upgraded pully ($275 ) If I find out that this is the source, I might even consider theirs, but thanks for the heads up about the crank pulley too, I'll be checking that out as well.

About the whine.........you nailed it on the head with your description , definately goes away under WOT but returns at "cruising" throttle position.I only really notice it when the windows are open, when I'm in tunnels, or even just going past barriers, still, kinda of a PIA. Thanks in advance for looking up the Goodyear number for me(us)( edit: man you're too fast !)

 

I chose the napa Belt...per the belt matrix someone here was kind enough to post!

15% Alta matrix shows either the stock belt or the napa 060539...Mechanic said it fit fine and no adverse effects so far.

I might add that for the lousy $20 I chose to change the belt when changing the pulley since we were in there anyway! Just a precaution

The oem belt was still in A+ shape after 20k miles...no glaze, cracks or wear evident! Hope I stay lucky...will keep it as a spare anyway!

 

[quote=gizzer777]I chose the napa Belt...per the belt matrix someone here was kind enough to post!

quote]

could you please post a link to this? Thanks

 

hehe, no problem at all. I'd don't waste time

i have personally heard a squeaking noise that was caused by a crank pulley that was loose. I've seen a couple of threads, one of them quite recently actually, where people are complaining about squeaking noises from the crank pulley. The crank pulley is heated and then pressed on to the crankshaft, if i'm not mistaken, so maybe high RPM and high heat might cause warping or permanent expansion.....

i'm not really a guru on this sort of thing, but maybe search around NAM for similar squeaking problems....

GTT sell a tensioner pulley, you might wanna have a look at that....

Here's a link for the GTT tensioner pulley. 2nd one down....

http://www.gtt.uk.com/parts3.asp

 

hell yeah i would like . you guys never cease to amaze me thx up front .

 

Hey there,

I had my 15% pully installed a few months ago - I was told the oem S belt OR the oem JCW belt would work fine. So... I bought a new oem JCW belt and had it installed at the same time. I saved my oem S belt to use as a spare ( just in case )


Good luck

 

ok, so now I'm a little bit confused , the Napa 060539 says on it: 13/16 x 54-1/2 ????? that's 3/4 '' larger than the above Gatorback. The lady behind the counter at NAPA said that their next size down is 54-1/8 (which for some unknown reason is $3.29 MORE ..even she couldn't see the logic in that). could someone post a link to this ALTA matrix that's been mentioned here a few times. what is the "correct" length for a car with a 15% pulley and a stock underdrive pulley and for that matter, just how much play is the tensioner capable of handling?
Jock

 

The stock tensioner can continue to apply adequate tension all the way to the top shoulder of the strap guide/stop; in my case without slipping. I’ve used the NAPA 539 on a 15% reduction pulley until nothing but the strap stop was showing before it started slipping above 6,500 rpm. For whatever it’s worth the NAPA belt showed more heat glazing on the back side and more stretch than Conti or Goodyear belts for similar lengths of service, even though the Goodyear belts were used on a smaller pulley. My first Conti had cracks on the lands after 20,000 miles but I looked at one yesterday with similar mileage with a reduction pulley and it looked as good as new. The stock Conti is ok for most SC & crank pulley size combos up to 18% reduction; I’ve seen this with my own eyes. I use the Gatorback 537 with a 19% pulley; the first belt showed part of the first hole on the guide strap after install and the second eclipsed the hole from the start so there are obviously manufacturing tolerances.

 

sweeeeet K-Huevo! Many thanks for the good info

 

i quoted you the inside length They quoted you the outside length, which is 54.5"

 

Goodyear Gatorback #4060537 (#6PK1365)

a pleasure