ISO of belt tension pulley WITH shoulders...

Wind driven rain permeated the engine compartment resulting in a wet belt and pulleys. Parked and cold, upon initial start-up, the belt slips, releases tension and walks off the tension pulley and wraps around the crank pulley. It's only happened twice, but the second time the belt was damaged. Question: Any recommendations/feedback on what brand of 'shouldered' tension pulley to purchase/ NOT purchase etc?
'94 6.5 K2500.
Thank You!

PS. I realize a shouldered pulley may chaff belt edge over time vs. flat pulley, but spitting a belt off and rendering it useless is worth the risk.

Take a look at the later style flanged tensioner pulley for the burbs. (1996 or so)
These have a flange...
They are meant to run on the grooved side of the belt....but may solve the issue....

If a belt is slipping off a pulley, even wet, something isn't aligned, is wore out, or the belt isn't routed properly. A "shouldered" pulley won't correct that, and may lead to a more serious failure. The belt should not lose tension or walk off a pulley because it gets wet. It may slip some under load after a cold start (alternator load or cold bearing seals/grease), but it shouldn't lose tension. If it's slipping or chirping/squealing, for any reason, the belt is used up or damaged (or poor quality), or the tensioner isn't tensioning properly. The tensioner can have a broken spring and still "feel" OK. A failing accessory can cause the belt to fail or come off, so check each and the tensioner/idler(s) for a smooth, silent turn with the belt off. If any of them are noisy, you can feel them turn, or they spin too easy, a bearing is shot. If a belt slips off a pulley while running, even once, it's likely damaged and will never be right.

Make sure it's the right (length) belt, too.

Thank You.

Very thorough info. Thanks!

Yes, belt length is correct. Thank You.

Quote:

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Originally Posted by The Munz

Yes, belt length is correct. Thank You.

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I guess what I'm saying is, make sure nothing has been changed that would affect the belt length, like installing the alternator from a gas engine, which uses a different size pulley...

I recall there are marks on the tensioner that will tell you if the belt length is correct.