ndg1979

OK Doc - Here is the patient:

1982 Pontiac Firebird Trans Am WS6 305ci (5.0L) 4-barrel V-8
Purchased in Zanesville, Ohio in June 2011 and is a survivor car (still need to get it certified as such). It had the factory original 15 inch Goodyear Eagle GTs on it when I bought it. It still has the factory original exhaust, suspension, paint, drivetrain, interior and is a numbers matching car. The only work I have done to it is to replace some factory engine parts with new parts maintaining as stock as possible but upgrading with stronger components. Car now has a double-roller timing chain, extreme-duty water pump, extreme-duty fan clutch, new OEM quick-ratio steering gear box, new OEM power steering pump, new front & rear OEM brake calipers/pads and new Cooper Cobra 215/65/R15 tires. Very little else has been done to the car since I got it as I lost my job in the recession in 2010, went back to college last year and will finish 2 degrees by the end of December 2012. It is actually my daily driver while I try to locate an Internship and then employment. I get tons of compliments on it and have plans to maintain its originality for as long as possible.



Here is the ailment:




I purchased a 17si 17290 Polished-Chrome Powermaster 120 AMP alternator about 6 months ago (Match 2012) and installed a new Dayco 15445 V-belt at the same time. 6 months later? The belt seems to be slipping but doesn't make the squeal that a normal slipping belt does unless the engine is quickly revved or under a load. Instead, it simply gets hot and I smell rubber inside the car. The belt is properly tensioned. When the belt does start to slip/smell, the alternator gauge reading goes from a solid 14.9 volts to 13 and holds steady. Sometimes, when I first start the car, the gauge will read 13 then slowly move up to 14.9 in about 30 to 60 seconds. Other times, the alternator will stay at 13 and the belt will smell. THE BELT DOES NOT GET HOT AT 14.9 VOLTS. Only at the lower reading. This entire situation is irrespective of whether the engine is hot or cold - it does not matter.

This is a chrome-polished alternator (the ONLY alternator Powermaster had of this size for my car). The factory-original was this size as well. My question is - Could the belt be the problem? Do I need a belt that grips better? OR Is the inside of the pulley wheel the problem? The pulley is not as polished inside as the alternator is, but is still fairly smooth.

The local Advance Auto and AutoZone do not carry the Goodyear Gatorback belts. RockAuto doesn't show Gatorbacks in its listing for this car, just Goodyear Freshstart belts. I did write to Powermaster for their suggestion as well.

Diagnosis please DOC????

Thank you!

Nathan from Beaver Falls, PA

8t2 z-chev

looks like the pulley is the problem-too small diameter and looks like the
groove is meant for a wider belt-original size belt is riding too low in the
groove and not gripping.

ndg1979

Thanks for the tip 8t2.

Any idea if the the belt could be "upsized" and still fit the crank wheel?

I did receive a reply from Powermaster (they are awesome at helping their customers!!!!) and the indication was to make sure the belt was extremely tight. I have re-tensioned it and there isn't much flex in it at all. I intend to replace this belt anyway and will attempt to ensure it is extra-tight.

I also intend to buy a stronger made belt. Hardly anyone around me deals with Goodyear belts.

ndg1979

Just got off the phone with a local engine builder I had remembered was nearby. Their diagnosis matches 8t2's response. The belt is too narrow for the pulley wheel and over time has bottomed out causing it to slip inside the wheel. It won't matter how tight the belt is, if it is the wrong size and has the wrong pitch angle, it will slip no matter what. The crank pulley wheel and the fan clutch wheel are still stock so any belt I buy will have to fit those as well.

Their recommendation is to search out a wider belt with a different pitch angle by taking the car to a NAPA store or other store with experienced help. I will do that and will post the results here. I have seen the engines of this shop in action and they can run the 1/4 mile all night without breaking a sweat. The engine I saw was in a late 1970's pickup and it ran faster than some mustangs and corvettes. The shop is called C.J. Rombold Engine Builders of Beaver Falls, PA.

eseibel67

You can get the same V length belt in a wider size, but then it will ride too high on the water pump and crank pulley. Do you still have your old alternator? Would you consider swapping in the old pulley and painting it black?

8t2 z-chev

need to replace the pulley with a standard one-original '82 pulleys are
stamped steel and use a spacer between the pulley and alternator fan,
some original GM pulleys used on certain other apps were machined steel
and do not use the spacer-one app that uses the machined pulley is
early-80s cadillac 100A alternator. I used standard diameter GM pulley
on my car for years,but had trouble with the belt sometimes rolling over
in the pulley grooves and breaking when engine revved to over 5500 RPM
-installed a '67-69 z/28 style deep groove larger diameter alternator
pulley to cure that problem-was not direct fit,had to turn the back face
down a little to get the offset right

Edwardgp

eseibel67's idea gets my vote. Would have already done something like this if it was mine. Let us know what you do to fix this problem.

TreeFiddy

That's what I did - new alt came with a v pulley, I needed a ribbed one. Removed the correct pulley from my old alt, painted it black, put it on the new chrome alt.

Edwardgp

Now just get out and cruse,Winter is on the way.