I just aligned my pulleys and I started up the engine, lt it warm up and revved it to try and get rid of a lifter tick, and I noticed a whirring sound and saw that my fan (V)belt flipped over. It was still on and spinning, just twisted about 120 degrees with the toothed side up at an angle. It has the stock steel 2 row pulley on the crank, a Summit chrome water pump pulley and the alternator has a Summit chrome water pump pulley. This is a lighter picture to better show the pieces involved, but before I aligned the pulleys, the alt. was about 3/16" off. Not a very good picture, but this is after the alignment and a shorter belt to be less at the end of the alt's adjustment. Could there be something out of plane? Is there a better quality belt or pulley that is less like to cause problems? P.S. I've had Corvairs with their goofy belt arrangements and never thrown a belt, so the fact that this is such a simple set-up and it doesn't want to behave is baffling.
I just went through a belt twistage issue with my daily. The belt that was twisting had thrown itself off before. Apparantly, sometimes belts have a "memory". If it gets tossed off and twisted, it'll keep wanting to return to the twisted form. I ended up tossing new belts on, problem solved.
Also, Check to make sure your belt is not seating in the root of the pulley.They are designed to run along the edges of the pulley.
That alternator still looks off a bit in the 2nd pic. Looks like it needs to be spaced towards the front at the top. And once a belt twists over, it's done. time for a new belt. Just my .02 Jay
It still looks out of alignment to me? It looks like the alt is ****ed back a little on the far side, maybe it's just the picture, my Big Block El Camino I installed a 3/8 bolt on the top alt bracket about an inch above the belt and stopped tossing belts after that I should have spent the cash for the GM deep pulleys, but hey I'm cheap!
That belt looks like it's riding in the bottom of the pulley groove on the alternator. Usually the belt doesn't sink deep into the pulley, the flat of the belt is just even with or a hair above the pulle sidewall. And YES the flipped belt is now junk, don't reuse it. I always use Gates belts and hoses, never a failure, never a problem.
looks like an alignment problem to me too. Put a straight edge on the water pump pulley and see how it lines up at the alternator.
I would say it is still off. shim it out at the top, p*** side, new belts??? I run flatheads and never have a problem with belts....
Put the alternator back on as it was before: no shims, no extra bends, etc. Then take a straight edge and set it through the alternator pulley and the crank pulley, to see if it's off. Then thru the crank and the water pump pulley, then thru the water pump pulley and the alternator pulley. My bet is that you're going to find the water pump pulley is too far forward. Pull the water pump off, remove the rear cover, support the shaft specifically, and make sure the "ears" of the pump (the water p***ages) aren't supporting the pump housing either. Then press the pulley hub further down onto the shaft. When they ***embled the pump, they didn't press the hub down far enough onto the shaft, and that's the problem you're having here. I ran into it with the water pump on my Suburban, after I replaced the pump and the harmonic balancer. I thought the balancer wasn't seated, but after a bunch of guys here giving me a bunch of different dimensions, I discovered the balancer was spot-on. That's when I took the straight edge (a long paint stir stick from Home Depot) and discovered the pump hub was way the hell off. A water pump bearing is a sealed bearing with a shaft running thru it: the bearing is pressed into the pump housing, the impeller is pressed onto the shaft inside the housing, and the pulley hub is pressed on outside the housing. The impeller is easy to eye-ball: if the cover goes on, the impeller is in the right spot. The hub? Not so much, and it can be off by half a groove. That's what mine was, sounds like that's what yours is, and I have read several other posts on here and other sites describing the exact same problem. If you just set the pump on a flat surface and press the hub on further, you can either press the bearing out of the pump, or you can break the ears off the pump body. I backed mine up on a deep well socket, and pressed it on with another deep well socket on the hub. -Brad
Alignment tool: Get a 3' piece of cheap roundstock steel, maybe 3/8" siameter, at Home Depot. Bend it about 90 degrees, using corner of store as fixture, lay one leg into grooves of two pulleys, other against third pulley.Since it is held in two places by the pulley at the bend, it cannot full yseat in all 3 if they are misaligned.
Once a belt flips its history. I found out a few years ago to take my gl***es off when I'm eye balling things. My gl***es distort things a little and what looks level and or straight is off by the well known curly hairs.
Pulleys have to be in line axially, and the grooves have to be parallel. The parallel thing can be a little tricky, but some of the guys have provided some good suggestions.
Sometimes holding a big L-shaped carpenter's square in the grooves of the three pulleys helps to eyeball whether things are aligned right. Go by the center of the grooves. Eyeball whether the carpenter's square looks parallel to the front of the block top to bottom and side to side. A length of straight steel rod ~1/4" in diameter held down in the groove of the pulleys also helps to check alignment. Sometimes your eye plays tricks on you just looking at the pulleys by themselves, since the front of a pulley might have more or less surface to it than the back of a pulley, and you might ***ume that the center of the groove is in the midpoint of what you see of the edges of the pulleys. Using straightedges or rods that actually sit deep down in the grooves gets it more accurate.
One more thing. Make sure your pulleys are flat. I've had a few cheap import chrome water pump pulleys that were bent, and they would wobble front to back when they spin. You can sometimes straighten them out by just bending them back straight again with brute force.
I learned along time ago that buying the thinest or skinniest belt I could find went along way tword warding off belt issues on some pulleys. My 56 would twist and ultimately throw its belt religiously (4 speed, steep gears and revs). I bought several of the best (I thought) belts I could find. Gates, Goodyear it didn't matter as all would twist. I shimmed, aligned, swore and prayed and nothing worked. One of the guys at work mentioned that the newer "improved" belts were actually thicker or wider in the shoulder area and did not ride deep enough in the pulley as the early belts. Sure enough I went and bought the cheapest, thinnest (kelly springfield in my case from autozone) andit fit deeper in the pulley and has yet to twist or come off. Just a thought.
Could it be too tight? A few moons ago when travelling in France, our V-dub's generator belt failed. The frog mechanic only had French car belts. The only one close to fitting was so tight the motor would not crank, so we push started it. When we reved it up, the belt flipped on one side and ran perfectly for a long while, until we could get a correct belt. Gary
That's how I aligned them... with a carpenters square... Since I apparently need a new belt, I'll try and find a thinner one.
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