As some of you may recall, I put a GM Performance crate 454 in my Allegro (I bought the rig with a blown engine). I swapped over the brackets and pulleys from the blown engine to the "new" engine. The only exception is the smog pump. The crate engine didn't have one, and had the appropriate sized belt to account for the lack of a smog pump.
Since the engine was used, and the belts too, I cross-referenced the old NAPA belt to a Gates 7470 (the NAPA belt said 7470 on it, too) and put a new belt on it. Well after about 30 miles of driving the new belt is trashed. The edges are chewed up and it's missing a lot of teeth.
It appears as if everything is lined up properly and the pulleys look good. Can overtightening the belt cause this? It kept loosening up and slipping so I made it pretty tight using a crowbar. I've ordered 2 more belts to experiment with but they're pretty hard to come by.
Since the engine was used, and the belts too, I cross-referenced the old NAPA belt to a Gates 7470 (the NAPA belt said 7470 on it, too) and put a new belt on it. Well after about 30 miles of driving the new belt is trashed. The edges are chewed up and it's missing a lot of teeth.
It appears as if everything is lined up properly and the pulleys look good. Can overtightening the belt cause this? It kept loosening up and slipping so I made it pretty tight using a crowbar. I've ordered 2 more belts to experiment with but they're pretty hard to come by.
I had the flex issue on my 79 chevy c30 truck with a 454. Before that I had the same rust issue with the pulleys. I replaced them all with aluminum ones and then noticed the flexing issue. I had heard that the napa belts, autozone belts and drive rite belts don't have as many threaded layers which causes the belts to be more elastic and stretch while in use, causing them to flex more, especially those belts with teeth on the inside. Dayco belts have more thread layers, with no inside teeth and don't flex as much because they don't stretch as much while in use. And it just about stopped the flex issue on my truck.
I made a custom bracket to install the same style chevy 12si alternator onto my 72 VW beetle. There was only one spot in that tight engine compartment to put it and had horrible flex with a drive rite belt to the point it kept throwing the belt off. Switched to a Dayco and the problem went away.
I do like the mid mount bracket tho, I didn't even know that existed. Might do that on my truck someday, but i won't do it on my RV as having the alternator higher up makes it a lot easier to change on my pace arrow. If it was as low as the mid mount, I wouldn't be able to get to it without removing the entire engine cover which would be a huge pain, especially If it went out during a trip. I keep my old alternator with a new pulley in my parts compartment where I store emergency oil, antifreeze, extra cap/ rotor, etc.
I made a custom bracket to install the same style chevy 12si alternator onto my 72 VW beetle. There was only one spot in that tight engine compartment to put it and had horrible flex with a drive rite belt to the point it kept throwing the belt off. Switched to a Dayco and the problem went away.
I do like the mid mount bracket tho, I didn't even know that existed. Might do that on my truck someday, but i won't do it on my RV as having the alternator higher up makes it a lot easier to change on my pace arrow. If it was as low as the mid mount, I wouldn't be able to get to it without removing the entire engine cover which would be a huge pain, especially If it went out during a trip. I keep my old alternator with a new pulley in my parts compartment where I store emergency oil, antifreeze, extra cap/ rotor, etc.
Bugman114 wrote:
EDIT: I went back and saw the pictures of your pulleys, and they look very rusty and rough. They looked even worse then my old ones.
Thanks for the info and pics.
Yes, they were pretty rusty. The rust didn't seem to be an issue until they started slipping. Then they shredded immediately. So far I've gotten almost 500 miles on the same 2 belts. Edges are a little frayed but not terrible. But like I said, the alternator belt needs tightened every trip out. Like someone else mentioned, without the smog pump that's a very long run from the crank to the alternator.
I'll look into replacing the pulleys but I'm definitely going to get a "mid mount" bracket for the alternator.
I have a 1985 p 30 pace arrow with the exact same problem. Turns out it was the pulleys themselves. Check the grooves of your pulleys, if they aren't absolutely smoothe and shiny, that IS your problem. Over the years and period of sitting, they tended to rust and when driven, any roughness inside the pulley groove would shred the belts. I kept loosing alternator belts every 100 miles or so. I'd notice the volt gauge drop and had to put the belt back on. So to not have to worry about the pulleys ever again, I went to summit and bought all new aluminum pulleys. But if you do MAKE SURE YOU GET STOCK SIZE PULLEYS!!! They sell a lot of underdrive pulleys for hot rods to slow the rotation of everything for more power, not good for an RV to have a slower rotating waterpump. I also removed the air pump since the pulley was pretty nasty too. You have to remove the entire pump, not just the pulley as the pump itself sticks out too far and will interfere with the belt. The only pulley I didn't replace was the power steering pump for 2 reasons. One being that I haven't had a problem with that belt, and the other being it's pressed on, and it's a pain to remove unless you pull the pump out which is a messy job by itself. So ill do it later if it becomes a problem
Here's my interior:
With the lid off:
I took the whole cover off to give me more room to work:
Here's the alternator. You can kinda see the roughness in the groove of the old one. I decided to upgrade while I was there, to a 100 amp alternator. The steel pulley it came with is junk, way too thin for the proper belt, so I got an aluminum one. BTW, that's NOT a double pulley, it's the reflection of the first pulley in the shiny chrome fan cover. Alternator was $100, the pulley was like $26:
Here's the water pump pulley. I think this one was like $40:
Here's the crank pulley. In the outer alternator belt groove doesn't look bad in the picture but this because the groove was so rusty, it's caked in rubber from all the belts it's shredded. A quick wire brush revealed how rough from rust it was. There were several manufacturers that claimed they were selling a stock sized pulley at 6.x inches diameter, which is smaller. There was only one that had a true 7 inch diameter pulley, I believe it was billet industries, I think the one by March performance was 6.X inches. IIRC this one cost like $75:
Before I was lucky to get 50 miles before loosing the belt, it's been over 1000 since i put the aluminum pulleys and the belts still look perfect and they're still nice and tight. Keep in mind after 20-50 miles or so a new belt WILL stretch a little, and will require you to re tighten it. But after that you're good to go. Hope this helps. Good luck 🙂
EDIT: I went back and saw the pictures of your pulleys, and they look very rusty and rough. They looked even worse then my old ones.
Here's my interior:
With the lid off:
I took the whole cover off to give me more room to work:
Here's the alternator. You can kinda see the roughness in the groove of the old one. I decided to upgrade while I was there, to a 100 amp alternator. The steel pulley it came with is junk, way too thin for the proper belt, so I got an aluminum one. BTW, that's NOT a double pulley, it's the reflection of the first pulley in the shiny chrome fan cover. Alternator was $100, the pulley was like $26:
Here's the water pump pulley. I think this one was like $40:
Here's the crank pulley. In the outer alternator belt groove doesn't look bad in the picture but this because the groove was so rusty, it's caked in rubber from all the belts it's shredded. A quick wire brush revealed how rough from rust it was. There were several manufacturers that claimed they were selling a stock sized pulley at 6.x inches diameter, which is smaller. There was only one that had a true 7 inch diameter pulley, I believe it was billet industries, I think the one by March performance was 6.X inches. IIRC this one cost like $75:
Before I was lucky to get 50 miles before loosing the belt, it's been over 1000 since i put the aluminum pulleys and the belts still look perfect and they're still nice and tight. Keep in mind after 20-50 miles or so a new belt WILL stretch a little, and will require you to re tighten it. But after that you're good to go. Hope this helps. Good luck 🙂
EDIT: I went back and saw the pictures of your pulleys, and they look very rusty and rough. They looked even worse then my old ones.
cncsparky wrote:
After removing my smog pumps, the alternator belt by itself became too long IMO.
I ended up using a mid mount alternator bracket. Much smaller belt and so far no problems. Part number 225R
http://www.alangrovecomponents.com/Big_Block_Long_Pump.htm
I'm finally going to do this - relocate the alternator. I just can't keep that alternator belt tight. When it's running, I can see it flopping around on the long run from the crank the alternator. I have to tighten it with a crowbar every trip out.
Power steering belt is behaving, thankfully.
I have a couple of spare belts for each application but so far haven't needed them (knock on wood).
Thanks for the link!
JumboJet wrote:
If none of that works out for you, and the $$ want hurt you, convert to a serpentine belt setup.
I hadn't realized this was possible, but it makes sense. I'll have to look into that. I have a PS pump and alternator for an LT1 (twas a Roadmaster wagon with the tow package so it's a high amperage alternator). Wonder if they'd work?
Okay - fixed the PS pump. It wasn't slipping, but that belt never would have held up. First, it was in the wrong crank groove. Second, the pump was loose in the bracket allowing it to pivot toward the water pump.
Before:
After:
I'm hoping a new belt and proper tension will fix the alternator belt. I don't know what would cause it to be misaligned. I dug out the other set of pulleys and they're identical. My recollection was incorrect - the crate engine WP pulley only had one groove that appears as if it lined up with the alternator. The stock engine WP pulley has 2 grooves - one for the alt and one for the ps pump. That's the one that's installed. Both crank pulleys are identical, with 3 grooves. The third groove appears to be for a second ps pump pulley which I understand they stopped using at some point. I've seen older (70s) 454s with both belts, but it's obvious a belt has never ridden in that spot on my ps pump nor on the crank pulley.
Before:
After:
I'm hoping a new belt and proper tension will fix the alternator belt. I don't know what would cause it to be misaligned. I dug out the other set of pulleys and they're identical. My recollection was incorrect - the crate engine WP pulley only had one groove that appears as if it lined up with the alternator. The stock engine WP pulley has 2 grooves - one for the alt and one for the ps pump. That's the one that's installed. Both crank pulleys are identical, with 3 grooves. The third groove appears to be for a second ps pump pulley which I understand they stopped using at some point. I've seen older (70s) 454s with both belts, but it's obvious a belt has never ridden in that spot on my ps pump nor on the crank pulley.
USAFBILL wrote:
Had a similar problem on the same unit purchased used. Finally an old back yard mechanic told me that they had installed a rebuilt alternator from Mexico and that the rebuilt unit had a metric pulley instead of an American. Anyway he went to a junk yard and brought one back that he said was the right one. How true that was I do not know but it took care of my belt problem...Good luck
Could be. I had 2 alternators at one point, but one sounded crunchy when I rotated it so I tossed it. I hope I don't need a new alternator...
wolfe10 wrote:
The first photo clearly shows that the water pump and alternator are off-angle from each other. The water pump pulley really shows that the belt is at an angle.
I didn't think it looked that bad. In the third pic the PS pump belt is really out of whack. I wonder what's going on here? I'll have to take the belts off and make sure everything is tight.
MountainAir05 wrote:
Plus all the pulleys look really rusty. If pitted then any slip and it would rip up a belt.
Yes, they are. Believe it or not those were the least rusty of the set. I *think* I have the original water pump pulley with 3 grooves in it. If I do I'll pop it on and see if the PS pump and alt line up better. I had eyeballed them before I put the 2-groove pulley on and they appeared to be exactly the same except for the extra groove for the air pump.
cncsparky wrote:
I ended up using a mid mount alternator bracket. Much smaller belt and so far no problems. Part number 225R
I like that! I don't have access from the front. How hard is it to get at the alternator down there? There's a solenoid mounted on the stock bracket that I can relocate. What belt do you use with that?
96bounder wrote:
In my business (starter/alternator rebuild shop) I have experienced this on several occasons.Problem is the alternator belt is slipping and burning the belt off.By looking at pics of your alternator pulley I can tell its been very hot caused by belt slipping.
IIRC the 84 model uses either a 15 or 17 si delco alternator ,the units were a bear to pull and many had same problem you are having
Don't be afraid to tighten the belt.
try tighten the belt until you can turn engine by placing a wrench on nut on the alternator and rotating it.
After a run n time check belt tension again.
Yes it had been slipping, and I guess with the rusty pulleys it didn't last very long. I'm going to investigate more and install a couple of new belts - I'll get the alternator belt as tight as I can get it. It has a Jet Ride air bag system with a pretty big pump. It's a big draw at startup - you can hear the engine idle pick up when it shuts off.
