3G Small Case Alternator Belt Troubles

[BDCarrillo]

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Well apparently belt clearance with the 3G small case alternator is less than ideal. On a test run it kissed the head of that bolt. Looks like a side effect of the smaller frame, with the pulley sitting lower in the whole belt system.

Solutions/ideas? Shorter belt? Idler?

UPDATE
Belt #17425 direct from water pump to alternator works. My issue seemed to be with an old, stretched, belt that was an inch longer than it should have been... a proper stock belt may still work fine.

Running a short belt on a non-ac is not recommended. There was significant belt slip on the crank pulley with only one belt transferring power. Long story cut short: stick to stock belts and large case alternators to reduce headaches.

 

[laserjock]

Hmm. Watching as I may be in the same boat.

 

[BDCarrillo]

Short belt direct from water pump to alt, part # 17425 looks to be the simplest solution so far.

 

[laserjock]

So one belt from crank to WP to ps one alt to WP, alt to vac pump and crank WP and AC?

 

[jwalterus]

get a socket head bolt, head'll be smaller diameter and round

 

[BDCarrillo]

So one belt from crank to WP to ps one alt to WP, alt to vac pump and crank WP and AC?

Yes, essentially. I also picked up a couple others to see if the stock routing can be done but with a shorter belt, which may move the alt enough.

get a socket head bolt, head'll be smaller diameter and round

Not a bad idea, but I just picked up the belts today... needed new ones anyway

 

[laserjock]

That's like a 6" 7/16 bolt. Might be tough ish to come by. Would a longer belt let you get on the other side of it or not enough adjustment?

 

[jwalterus]

That's like a 6" 7/16 bolt. Might be tough ish to come by. Would a longer belt let you get on the other side of it or not enough adjustment?

7/16 - 20

https://www.fastenal.com/products/details/23869?r=~|categoryl1:%22600000%20Fasteners%22|~%20~|categoryl2:%22600039%20Sockets%22|~%20~|categoryl3:%22600040%20Socket%20Cap%20Screws%22|~%20~|sattr04:^%227/16%22%20-%2014%22$|~%20~|sattr04:^%227/16%22%20-%2020%22$|~%20~|sattr05:^6%22$|~

7/16-14

https://www.fastenal.com/products/details/23375?r=~|categoryl1:%22600000%20Fasteners%22|~%20~|categoryl2:%22600039%20Sockets%22|~%20~|categoryl3:%22600040%20Socket%20Cap%20Screws%22|~%20~|sattr04:^%227/16%22%20-%2014%22$|~%20~|sattr04:^%227/16%22%20-%2020%22$|~%20~|sattr05:^6%22$|~
took me all of 30 seconds to find

 

[laserjock]

I didn't mean didn't exist but it's probably a special order.

 

[madpogue]

How long is the shaft? Maybe the pulley could be adjusted forward on the shaft a mm or so. I bet with the smaller frame, the pulley is further back than the WP and crank pulleys anyway, out of "plane" with them.

An idler on the path between the crank and the alt, pushing upward on the outside of the belt, would also change the path slightly, possibly enough to move it away from that bolt head. Just a thought...

 

[BDCarrillo]

The pulley could be shimmed out a brunette one before running out of thread. I knocked a few mm off the alternator case mount and shimmed the whole thing forward to get good alignment already.

An idler is another option, but I think I'll be set with the short belt. More to follow, I'll get time to work on it tonight.

 

[riotwarrior]

Y small case is my question

 

[BDCarrillo]

Y small case is my question

I knew that's what you asked before I opened the thread... I had all the extra parts on hand from a 3G swap in the Mustang, which is also a small case. I didn't want to buy heavier gauge wire, another fuse, new crimped fittings... blah blah.

Anyway, I have zero additional electric load in the truck and felt a 95a would be fine. At the end of the day it was $66 out of pocket for a new DB alt and $6 for a belt.

 

[riotwarrior]

I knew that's what you asked before I opened the thread... I had all the extra parts on hand from a 3G swap in the Mustang, which is also a small case. I didn't want to buy heavier gauge wire, another fuse, new crimped fittings... blah blah.

Anyway, I have zero additional electric load in the truck and felt a 95a would be fine. At the end of the day it was $66 out of pocket for a new DB alt and $6 for a belt.

Lg case offers maybe better clearance is where I was going...not load

 

[BDCarrillo]

Lg case offers maybe better clearance is where I was going...not load

Oh, ha! I expected to get harassed about a dinky little alternator The large case should be a perfect drop in, as I've read about many easy installs.

That same reading lead me to believe the small case would work just fine too, BUT it appears that a slight changeup in the belts or a specialty bolt is required.