Did 3G alt conversion, need second belt. How?

[greyscar]

The Belt is setting Deep in the Alternator Pulley, tells me it's not the right size V-belt for that Pulley. Your pulley V-belt widths are Mismatched causing it to eat belts . Look at the way the Belt sits in your other Pulleys. The Belt groove on the 3G is deep and Pinching the Belt.

[JoshT]

The belt is the correct size and the widths are not mismatched. That belt part number and manufacturer has been used to drive the alternator on this truck for decades without issue. That belt or equivalent part number is called for everywhere. That alternator pulley has been used on the truck for at least the past 30 years, at least as long as its been in the immediate family, and moved from the original 1G alt to the new 3G alt.

Both belts are same manufacturer and size, but different lengths. Dayco Top Cog 15450 for the Alternator, Dayco Top Cog 15520 for the PS pulley. The reason the alternator belt looks smaller and is sitting deeper is because the its slipping and destroying the belt. When new belt first installed its sitting just like the PS belt does, as it wears and slips, tighter I've got to make it and deeper into the pulley it gets. Look at the Alternator case you can see the residue that's been worn off of the belt.

Only thing that had changed in the last 30 years (as far as that belt is concerned) is the alternator was upgraded to a 3G. Greater load takes more power to turn. Single v-belt just doesn't cut it with this larger alternator. I think that the double groove pulley I installed will do the job, but got to replace the intake gasket before I can fire it up again. I think that a larger diameter would probably work as well, but I needed the new pulley setup to run A/C in the future.

[greyscar]

My apologies I didn't recognize in your Post you used the same Pulley. I ran a 3G with one belt for years never lost a Belt. I think when you get the 2 Belt setup done you will be buying 2 Belts. 'The alternator is seizing up when it gets Hot and slowing the Pulley down, a 3g has absolutely no issue running with one Belt. Your Alternator is Taking a Crap.

[JoshT]

Or it could be that you got lucky running a single belt, some people do.

A little time spent searching online about 3G alernators into older v-belt systems will show that a lot of people have the same belt slipping issue. I knew that it was a potential problem even before I did the alternator upgrade, it was still worth it.

It is common problem, especially with the 135a and larger versions. Most (not all) people that never have a problem are running the smaller 95a version. That is why the 95a version is recommended, but the 135a is much more commonly available.

Even the high output 1G alternators used back in the 60s & 70s needed two belts to prevent slippage. They were less efficient than the 3G alternators, but still shows that a second v-belt is not uncommon.

[JoshT]

The alternator is seizing up when it gets Hot and slowing the Pulley down, a 3g has absolutely no issue running with one Belt. Your Alternator is Taking a Crap.

Also not when alternator gets hot. It can be dead cold and slip, it can be warm and slip. Some times it slips for a moment at first starts and goes quiet. Other times it starts at first startup and keeps going all day. Like I said previous it doesn't matter how much I adjusted the belt.

Either way I've got dual belts driving it now. While I have no doubt it's going to work, I won't be able to test until until the intake gasket is replaced. About ready to pull the intake, but working in an open "pole barn" and its colder than a witch's titty. Also need to track down some parts for my rocker assemblies so it might be a bit before it gets back together.

Just for a follow-up. Here's the new pulley arrangement installed.

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[image]1197[/image]
[image]1198[/image]

Not the greatest pictures, might see about getting some better when I get done with the intake gasket replacement.

[greyscar]

Good Luck and I hope you get it Cured, These little Ticks every now and then will drive you nuts.

[basketcase0302]

"JoshT" its colder than a witch's titty.

Hadn't heard that one in awhile, had a buddy that used it all the time LOL!
But he'd add...
On New Year's Day!

Good job on the pulley's Josh!

[DuckRyder]

Or "in a brass bra..."

But remember, family friendly site...

[JoshT]

Sorry about that. Haven't heard the term in a long time either, but it felt entirely appropriate for that day. I'll go back and edit the post of you want me to.

[DuckRyder]

Sorry about that. Haven't heard the term in a long time either, but it felt entirely appropriate for that day. I'll go back and edit the post of you want me to.

No man you’re fine... I was just saying lets not go any further

Back to dual belts...