pmj341

I installed a new Belt 500 miles ago, and it just came apart today while on a cruise, A/C was not on!!!, tensioner looks good, aligment does too!!
any one have this problem??
thanks
Phil

Walt White Coupe

Sounds like a bad belt.

pmj341

could be!!!
I'll take it back tomorrow, what's left !!!

bterwilliger

Less coffee!!! But really, if you aren't certain you had your AC off, it very well may have been on (as when running in defrost/defog mode). Any chance it was nicked going on?

pmj341

I'm sure I had it off couse I was doing some data logging on HP Tuners
as far as the nick, it's possible it went on real hard.

patton

if you have a lot of miles on the car check the idler/tensioner pulley for wear. they need to be flat where the belt rides

Joe_G

Uh oh....sounds like your balancer is coming loose, you better check, this is often the first sign....

lgm118icbm

That happened to mine a few weeks back. Its still broken, sitting at the dealer with the parts "on backorder" from GM

CMY SIX

check IDLER PULLEY

pmj341

Well, it's a new UD balancer, new belt. aligment was perfect!!
the only thing left is the tensioner!!!
I used all new parts when I assembled the 427, except the A/C belt tensioner.
thanks

Joe_G

Phil you wouldn't be the first guy who had a newly put together motor have the bolt back out...it's pretty common. Even my buddy who's a great tech had it happen to him.

Do you have a laser thing available to align the pullies? That wil ltell you if the lower pulley is out of alignment.

pmj341

Joe
I took a straight edge from a/c comp to balancer and it's great, the Arp balancer bolt has not moved.
what else do we have??

Joe_G

Hmm. That sounds like good news. Maybe you just got a bad belt, though that sure seems rare anymore. I think I'd buy another belt and watch it in action to see what I saw!

pmj341

I'll replace the belt and put a new GM tensioner and Idler pulley
Hope for the best!!

Joe_G

Sounds like a good plan. I have a spare tensioner I would send you, but, unfortunately it's the main tensioner.

Get your car fixed by Saturday and make some passes at the Corvette Challenge this weekend at Palm Beach International! Unfortunately my car has no diff and I've got a work engagement so I can't go to this event. It should be fun there is a lot going on at the track that day, see racepbir.com.

pmj341

Joe
I'll send you a pm
phil

pmj341

Well after visiting the local GM dealer and speaking to one of the tech's, he mentioned problems with the a/c belt tensioner, He said on the 6.0 trucks the tensioner under full power and higher miles, start to wear side ways causing the belts to come off.
they just replace the tensioner assy with a new one and problem went away.
I have no way of checking mine, so I'll replace it and maybe machine an aluminum idler with sides to keep the belt aligned.
I have a Katech main belt tensioner, I wonder if they make one for the A/C??

ByByBMW

Just a note, for those mentioning that the AC was off, I think the belt is still moving even with the AC off. AC on just puts more load on the belt.
Or did I read those post wrong?

Walt White Coupe

You are right.

pmj341

the A/C was off, yes the belt is still freewheeling with no load, when you activate the clutch then the compressor rotates.