Well I found out why I was snapping belts left and right, and why I was shearing the locating pins on the S/C crank pulleys.
My tensioner bearings seized. I think it was going gradually because I could spin it with some effort on previous belt replacements so I really didn't pay attention to it, now my hindsight is 20/20.

here is some pics







Now to the replacement of the bearings. I searched the forum because I remembered someone posting a heads up on this awhile ago, the original post was on the corvette forums.
The PN for the bearings are 203PP for the fafnir bearings. You can find these at Applied Industrial Technologies but the local one A.I.T in abq. is only open mon-fri. Soooo I checked Napa website for the 203PP PN but nothing came up. I then crossed that number on the pep boys website and came up with a Beck-Arnley PN 068-0035. So I went to pep boys with the PN in hand, no dice special order
I went home pretty pissed and hopped back on the web and checked Napa's website again as I know they carry Beck-Arnley( was a counter man there for a couple years) ran the B-A number through and it came up.
I called the local NAPA DC and they had 3 instock so I ran down there and grabbed two. They were 6.99 ea so an outlay of 14.XX wasn't that bad plus the 16.99 for the new gatorback from autozone
I cleaned up the tensioner/idler pulley up, the rubber was really cooked on there and it blued it from the heat it generated. Slapped in the new bearings and now she is good as new I HOPE. So if you have an ATI kit these bearings will fail. Don't wait till it does, go out and buy 2 spare sets or put them on order since they tend to be special order parts. I was lucky, the counterman at Napa said they were s.o. for them too, but they had 3 on hand from a cancelled order.
I know you guys get tired of my posts, but some of you might find the beneficial.
BTW the "Camarogod Steel Tensioner Pulley" is holding up awesomely after 12XXX mile on it. No wear at all and it handled the little incident above with no problems. Thanks camarogod for a well made piece.
Jeremy

 

Great info!I'm sure this will help alot of people for future reference.

 

Thanks, I hope it helps a few out.
For the bearing PN's that kinda get lost in my post they are
203PP,203VV, 203DD,203FF the blown out original bearings were 203VV on my kit. These bearings are available from Applied Industrial Tech.
Beck Arnley PN 068-0035, these are available on a special order basis from napa, checker, pep boys, and parts America part stores but you might luck out and find them instock.
J

 

Thanks for the info, I will keep an eye on mine, I've heard other people having similer problems with this...

 

The same thing happened to me(4k miles).Bearings siezed and the belt snapped. I have the same steel pulley from Camarogod. I came to this conclusion upon inspection. I believe that the extra mass of the steel pulley is too hard to spin up quickly(belt slips causing heat and wear) and also stores to much centrifical energy to be slowed down fast enough during "engine braking" or fast deceleration(more slipping,heat,and wear).

As time goes on (based on the way you drive) the constant slipping is causing the bearings to overheat causing them to fail. The excessive heat and friction on the pulley is also causing the belt to pre-maturely fail.

I had another stock ATI idler(15k miles never snapped a belt) that I've just swapped on for now. I plan on making a template and drilling quite a few holes in the steel pulley to lighten it. A bit of weight reduction and new bearings should solve the problem.

These are just my thoughts. I'd hate for you to fix this and just have it happen all over again.

 

I had the same thing happen to me.

Since I had recently switched to Camorogod's steel idler AND done the MMS pulley AND was trying to up the boost, I wasn't sure what was to blame (perhaps more tension than before). I did discuss this with camarogod. Since the idler itself was ok, but the bearings roasted, he speculated the MMS pulley and quest for more boost was too much for the small bearings in the ATI tensioner to bear.

Anyway, it's funny you show that belt and idler pulley condition. It just happened to me again Thursday (I'd switched camarogod's steel idler back in to replace my current ATI idler pulley that was wearing down again), and though the bearing assembly didn't explode this time (Gatorback was still on, but ripped), it had JUST happened while cruising at lower speed. This time the bearing assembly was froze where the idler would not spin and the belt had been cut and was hanging on my transmission lines.

It appears camarogod's steel idler is the common thread here?

 

I bought the steel idler from camarogod too. Do you think SSmokin's idea would be worth trying? What goes wrong with the stock ATI pulley? Do the bearings go? Or does the aluminum wear out?

Den

 

The aluminum wears off.

Sounds interesting. I have one of the steel idlers, but no problems. However, I'm still under 10k miles I think. The hole idea doesn't sound bad if you can get them centered right. Maybe a bearing replacement should be a little maintenance procedure every other s/c oil change? $14 isn't bad for 12k miles I think. And you get gatorbacks for $16? Man, my last one was like 20-25 I think...

 

I've conferred with Reichard Racing about the idler pulley issue. He is going to make a larger diameter idler pulley with larger bearings and test it out. This MAY do at least three things:

1. Make it tougher to explode/freeze the bearings
2. Cause the idler to last MUCH longer, even though it will still be the lighter, anodized aluminum
3. Create more belt-wrap about the supercharger pulley, perhaps reducing belt slip.

I'm anxious to try it.

 

To all that replied, I am thinking the samething. The steel idler is way too heavy. I do like the idea of the bigger tensioner, the belt wrap is what I would be interested in. But I wish we could have the best of both worlds, a pulley that doesn't wear down and is light too. Maybe RR can machine a steel one that doesn't way too much?
J

 

Reichard thinks the extra travel on a larger pulley will eliminate a significant amount of surface stress the current idler endures due to it's small diameter. He didn't seem to think going to steel was really neccesary if it was the size he'd like to machine.

 

I invited Jay (camarogod) to post to this thread.
I let him know we aren't bashing his idler, so keep it real.

 

Guys,

I've said it before. Sounds like you need to have a hard anodized aluminium pulley. (edit, I mean idler)

This is not a typical anodize process. In my experience, it's used in high wear aluminium jet engine applications. The process puts down an Rc 60 or so layer over the aluminium....maybe .0015 thick. Perfect for this situation.

Its for surface wear, not for strength. Absolutely the same scenario.

I forgot the PWA or AMS designations, but I can look that up if anyone wants.

In material science, there is a lot to learn from the aircraft industry.

 

Not bashing him at all, he made a wicked awesome pulley that held up to some heat and bad abuse. He is a great guy. Here is the last phrase from my first post:
BTW the "Camarogod Steel Tensioner Pulley" is holding up awesomely after 12XXX mile on it. No wear at all and it handled the little incident above with no problems. Thanks camarogod for a well made piece.
So like Mike(BLS1T/A) said, be cool to the dude

Mark C good info, I hope we can get it used for a new pulley.

Mike, I hope RR gets a quality piece out soon, We will be installing my new motor this weekend. So I want to run the MMS Pulley and my 3.2 with it to get some good boost going and I need to get some life out of these belts. So keep buggin them for us
J

 

I might be interested in trying out this RR piece....if it works out well that is...

 

That is cool, Mark... I'll see what Jimmy Reichard says about his anodizing process and quote you about it.

He thinks about two weeks he will have gotten to it and let me try it out. I'll definitely let you know what I think... but, keep in mind, it will take some run time to have really made a final judgement on it. It would HAVE to be better than a smaller idler with smaller bearings, regardless, right?

BTW... ATI's customer service is still awesome in my book. They shipped me a new idler pronto... they really get right on the ball when they ship stuff out.

They also have some plans about bettering the pulley system. I'll share that in another post when I can compose the mail and am not at work.

 

Any chance RR has plans to make a self tensioning idler? I mean since they are going through the trouble to redesign it anyways... This might be nice. Not sure how difficult it would be, just throwing the idea out there.

Mike

 

It hasn't been discussed... I guess that would be quite a bit more complex than just machining a pulley. If someone could come up with a cost-effective self-tensioner for the ATI on F-Body that would be great... if enough people purchase one to make it worthwile.

 

www.sd-concepts.com for the self tensioning system for our ATI powered cars. They have a 6 rib for 350? and a 8 rib with a larger crank pulley for 599. I think I will be getting the 6 rib for now, as that is all the cash I have right now. I will be calling them tomorrow to get the low down on this set up. I do know you have to send your brackets and stuff to them so they can modifiy them and check them for alignment issues. I threw this out awhile ago and got no response on this forum. Now that I am having major issues with ATI's design I can justify the 350-600 for another set up that gets rid of all the crappiness.
J

 

I will be using the SD-Concepts 8rib on my setup. Only looking for 10psi but I will be sure to post how it works out.