Alternator Bracket....keeps breaking!!!!!! WHY!!
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Alternator Bracket....keeps breaking!!!!!! WHY!!
OK, here's the deal. Over the past 5 years, I have replaced my broken alternator bracket 5 times. The first 3 times I replaced the stock bracket with a stock bracket. Like this:
. After about 8 months each one broke in the groved area (on top) where the alternator is bolted to. So I kept getting another one, and another one and another one. I even went and installed a ZOOPS aluminum bracket but didn't like the way it kept lossening, so I went back to the stock bracket...but this time, I had 2 of them bolted together (on the recomendation of several mechanics and parts guys), had it chromed and that set up lasted until TODAY when I saw it too was BROKEN in the same spot!!!!
This one lasted about 2 years.....
Like this:
So I went ahead and order this Billet Specialities aluminum bracket from Summit Racing...
Getting it Thursday....here we go AGAIN!!!!
So here's my question after going down memory lane....WHY in the he(( to these brackets keep breaking???? Does anyone else have the same problem???? What is the solution....I hope getting the $130 bracket will finally fix the problem!!!!
Let me know out there ok?
. After about 8 months each one broke in the groved area (on top) where the alternator is bolted to. So I kept getting another one, and another one and another one. I even went and installed a ZOOPS aluminum bracket but didn't like the way it kept lossening, so I went back to the stock bracket...but this time, I had 2 of them bolted together (on the recomendation of several mechanics and parts guys), had it chromed and that set up lasted until TODAY when I saw it too was BROKEN in the same spot!!!! This one lasted about 2 years.....Like this:
So I went ahead and order this Billet Specialities aluminum bracket from Summit Racing...
Getting it Thursday....here we go AGAIN!!!!
So here's my question after going down memory lane....WHY in the he(( to these brackets keep breaking???? Does anyone else have the same problem???? What is the solution....I hope getting the $130 bracket will finally fix the problem!!!!
Let me know out there ok?
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
i'm gonna be ordering brackets myself...alt/ps pump..... i want to run a cog drive kit so i have to by bracket separatly....
is the bracket shimmed so the pulley is in the same "plane" as the other pulley?..... maybe there's a twisting motion that happens when you accelarate and over time that creates a moment failure...... picture bending a paper clip back and forth about 20 times until it snaps....same concept but in smaller proportions.......
b
is the bracket shimmed so the pulley is in the same "plane" as the other pulley?..... maybe there's a twisting motion that happens when you accelarate and over time that creates a moment failure...... picture bending a paper clip back and forth about 20 times until it snaps....same concept but in smaller proportions.......
b
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Originally Posted by onaqwst
is the bracket shimmed so the pulley is in the same "plane" as the other pulley?..... maybe there's a twisting motion that happens when you accelarate and over time that creates a moment failure...... picture bending a paper clip back and forth about 20 times until it snaps....same concept but in smaller proportions.......
b
b
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
From an engineering point of view, the forces that bracket was designed to endure would not cause it to break as it does in yours.
I have ran the one on my vette for 16(4 years lost to restoration) years and they have been hard years and mine has never broke. AS well as most people on this forum , I assume.
I'd say look at the alignment of the pulleys, alignment of the bracket You have to be putting some torsion in the bracket to get it to break that way.. You have had multiple failures of the same bracket--- which means its not the bracket's fault (since the bracket has proven itself over decades of service in hundreds of thousands of vehicles)
I have ran the one on my vette for 16(4 years lost to restoration) years and they have been hard years and mine has never broke. AS well as most people on this forum , I assume.
I'd say look at the alignment of the pulleys, alignment of the bracket You have to be putting some torsion in the bracket to get it to break that way.. You have had multiple failures of the same bracket--- which means its not the bracket's fault (since the bracket has proven itself over decades of service in hundreds of thousands of vehicles)
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Originally Posted by MikeC
(since the bracket has proven itself over decades of service in hundreds of thousands of vehicles)
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
I have seen Alternator and A/C brackets that look very similar to "tie rod" with a threaded barrel at each end (similar to a turnbuckle...left handed/right handed threads)
I ran one on a SK Modified that I raced years ago
I know theyre still available but I cant recall the name.
Perhaps this will ring somebodys bell and they will be able to step in
Its very very strong and you could probably fabricate one yourself if you have the proper tools
I will look through my old pics of the stock car and see if I can find a pic
If I find one I will scan it and post it
EDIT*
Look at the bottom of the page for "Rod End Alternator Strut"
$30 and it will not fail.
http://www.engineceramics.com/hardpart/steriods.htm
I ran one on a SK Modified that I raced years ago
I know theyre still available but I cant recall the name.
Perhaps this will ring somebodys bell and they will be able to step in
Its very very strong and you could probably fabricate one yourself if you have the proper tools
I will look through my old pics of the stock car and see if I can find a pic
If I find one I will scan it and post it
EDIT*
Look at the bottom of the page for "Rod End Alternator Strut"
$30 and it will not fail.
http://www.engineceramics.com/hardpart/steriods.htm
Last edited by Bob Onit; Oct 21, 2006 at 07:51 PM.
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Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
My original broke in the same spot years ago, but it didn't really seem to hurt anything. I replaced it with an original-style bracket and it's been fine for 10 years. I think if you're breaking a lot of them, something is out of alignment, you have the belt too tight, or something else that is putting some weird angular stress on the bracket.
Instructor
Joined: Oct 2005
Posts: 143
Likes: 0
From: Independence MO
Bracket
You might check to make sure the pivot bolt is tight on the bottom of the Alt. If it is not tight this will let the Alt viberate and cause the bracket to move back and forth which would cause it to break. I know most people just snug their pivot bolt so they can move it to adjust it form time to time and if this bolt is not tight it will losen even more while driving. This kind of bracket has been around a long time so since you are having so many break it has to be something else.
Racer
Joined: Aug 2004
Posts: 354
Likes: 6
From: Winston Salem NC
I looked at your sig pics and have a few things you might want to check, if you haven't already.
1- check the shim washer behind the water pump pulley, mine had one.
2- use a straight edge on the face of the alternator pulley to see if the others align properly.
3- if you are doubling the bracket, you are pushnig the alt. pulley forward by a small amount.
1- check the shim washer behind the water pump pulley, mine had one.
2- use a straight edge on the face of the alternator pulley to see if the others align properly.
3- if you are doubling the bracket, you are pushnig the alt. pulley forward by a small amount.
Last edited by FB#1; Oct 21, 2006 at 10:30 PM.
Drifting
Joined: Mar 2001
Posts: 1,395
Likes: 6
From: Indiana
I had a similar problem a while back with breaking the lower alt bracket. However, my lower bracket was the aftermarket type used with headers. It turned out to be the alternator's chrome cooloing fan that came with my Powermaster alternator. The alternator fan was out of balance and would cause a serious vibration at certain speeds. I broke 3 lower brackets before solving the problem by swapping the chrome fan with the stock alt fan.
Team Owner
Joined: Jun 2001
Posts: 23,367
Likes: 1,061
From: Virginia USA
By looking at your pictures you are pretty far out in the adjustment slot. It looks like vibration is the problem. I would try a shorter belt to get the bolt closer to the "meat" of the bracket. The closer you get the adustment to the fixed part of the bracket it will change the resident frequency that your bracket seems to be vibrating at. Just a thought and it may save you some $$$$ on that fancy setup.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Vibration is killing the thing. An abnormal condition that you'd want to fix by finding the source. A stronger bracket addresses the symptom without curing the cause. Have you tried a different alternator? May just be a wobbly bearing in the high-zoot one you're using.
Burning Brakes
Joined: Aug 2002
Posts: 1,146
Likes: 10
From: Scottsboro Alabama
Originally Posted by vetteguy75
I even went and installed a ZOOPS aluminum bracket but didn't like the way it kept lossening, so I went back to the stock bracket.
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Think I found the problem....took the alternator off and spun it by hand as fast as I could. The fan/pulley has a slight warble it. So, I am taking the alternator to an auto electric repair shop and have them check it out. (Personally, I think you guys pointed me the right direction by checking out the balance of the alternator......would have NEVER thought it was the alternator) Thanks! Will report back when I get the info....
