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Losciuto

Alternator & A/C Pulley Not Lining Up After Replacing Brushes

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I have a Patriot Beaver (1999) with a CAT 3126, I pulled the Alternator to replace the brushes.  I did not remove the A/C.

I kept the bolts and washers together.  I reinstalled the Alternator and now the alternator pulley is off by 1/8" and it pulls the belt toward the block and over the lip of the A/C pulley.

I replaced the belt tensioner with a new one from CAT because I thought the belt was loose and slipping.

I believe I have shimmed the Alternator as much as possible because it is flush between the iron bracket and the alternator, but I am still coming off the pulley by one groove now, down from 2.

If anyone has had a similar problem please let me know.  I am on day 4 of trying to get the pulleys back in alignment.  I am not sure if I can shim the alternator pulley.  As noted above, the AC was not touched at all and I verified the alignment of the AC and the tensioner pulley.

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Did you remove the end bells (bearing housings) to replace the brushes?  If so the bearings may not properly seated.

 

Jim

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On 9/5/2017 at 5:54 PM, losciuto said:

I have a Patriot Beaver (1999) with a CAT 3126, I pulled the Alternator to replace the brushes.  I did not remove the A/C.

I kept the bolts and washers together.  I reinstalled the Alternator and now the alternator pulley is off by 1/8" and it pulls the belt toward the block and over the lip of the A/C pulley.

I replaced the belt tensioner with a new one from CAT because I thought the belt was loose and slipping.

I believe I have shimmed the Alternator as much as possible because it is flush between the iron bracket and the alternator, but I am still coming off the pulley by one groove now, down from 2.

If anyone has had a similar problem please let me know.  I am on day 4 of trying to get the pulleys back in alignment.  I am not sure if I can shim the alternator pulley.  As noted above, the AC was not touched at all and I verified the alignment of the AC and the tensioner pulley.

Could you post the make of the alternator for the group? Delco, Leece Neville  or other and is it a 130 or 160 amp version?

Bill and Jim asked good questions regarding your repair.

Rich.

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If the pulley was not removed, then if I understand correctly, only the rear housing would be removed to replace the brushes. That would leave the front mounts unchanged. Is this a 4 bolt pad mount or a 2 bolt mount ( long bolt as the hinge with short bolt on the adjustment slide)?

Is it possible to have the alternator on the wrong side of the mount?

Is it possible that the pulley may have not lined up when you pulled it apart? You sound as though you are fairly handy in the repair arena, But if you are not looking for that issue than it may have been hard to see and the last guy may have been lucky. Can that pulley be turned around or shimmed as another poster mentioned?

Just some thoughts.

Gary

Edited by garyreed
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It is a Leece Neville 160A.  You do not take the alternator apart to replace the brushes.  There is a plate on the voltage regulator box, I removed the 4 screws and the cover and inserted the new brushes in and put the 4 screws and cover back on. Then I reinstalled the alternator into the RV,  The alternator can only go on one way, and it can only be aligned in the set up one way to get the pulley into the correct position.  The one thing I am not sure of is that the pulley was aligned properly before I took it apart.  I did not want to tear into the pulley before I asked on here if anyone had the issue before.

I will try to get pictures.  It is a pretty standard set up, the 3126 has a cast bracket that holds the alternator.  The bottom of the alternator bracket  has a cast tube were the bolt goes through. There is a bushing on the aft end of the alternator which I have put flush with the alternator so I could use the space to put a shim on the front end of the cast piece.  This helped me cut the distance it is moving in half but I am still 1/16 out of alignment.

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15 hours ago, losciuto said:

It is a Leece Neville 160A.  You do not take the alternator apart to replace the brushes.  There is a plate on the voltage regulator box, I removed the 4 screws and the cover and inserted the new brushes in and put the 4 screws and cover back on. Then I reinstalled the alternator into the RV,  The alternator can only go on one way, and it can only be aligned in the set up one way to get the pulley into the correct position.  The one thing I am not sure of is that the pulley was aligned properly before I took it apart.  I did not want to tear into the pulley before I asked on here if anyone had the issue before.

I will try to get pictures.  It is a pretty standard set up, the 3126 has a cast bracket that holds the alternator.  The bottom of the alternator bracket  has a cast tube were the bolt goes through. There is a bushing on the aft end of the alternator which I have put flush with the alternator so I could use the space to put a shim on the front end of the cast piece.  This helped me cut the distance it is moving in half but I am still 1/16 out of alignment.

How about adding another 1/16 shim? Even if you need to file the other end to get clearance for it to move.

Bill

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Bill, 

I think that is the plan to try today (see if I can file down space for another washer), I have exhausted all other option.  I just wish I could have identified the cause since the alternator was the only piece ever removed from the system.

Joe

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3 hours ago, losciuto said:

Bill, 

I think that is the plan to try today (see if I can file down space for another washer), I have exhausted all other option.  I just wish I could have identified the cause since the alternator was the only piece ever removed from the system.

Joe

Joe, before you do the washer thing that Bill mentioned, you might just want to remove the drive pulley and flip it outside in / inside out and see if the alignment changes just enough to get the difference you need.

Rich. 

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Todays efforts included pulling alternator completely off, driving bushing back into hole in rear of Alt, sanding inner surfaces of Alt and cast iron bearing surfaces.  I reinstalled with a larger 3/16 shim. I tried it and had it come off 2 channels.  I then loosened the adjustment bolt on the top of the bracket as far as I could, this produced the best results of the day with it barely riding up on the rear lip of the pully but enough to eat the belt.  I do not believe I can get another shim into the hole as I only have 1/32 to deal with. I maybe adjusting it incorrectly, I am not sure at this point as I followed the directions listed on the ALT.

I could not get the pull off the ALT and did not want to fool with it too much as it looks good.

My only other option left is to start grinding the cast piece, I want to exhaust the adjustment issue first as an examination of the belt leads me to believe it was aligned before I took it apart.

 

Joe

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Try putting a straight edge on the face of the alt pulley and see how it lines up with the crank pulley.  Its possible that the alt is slightly twisted giving the illusion that it is not in line.

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Joe, did you replace the the fan belt? How is the tension on the Idler Pulley? If the belt is old and there isn't enough tension the belt may flap around and cause it to flop off. And as DD said check the alignment. I would do this before modifying any brackets or surfaces. 

Herman 

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The belt is fairly new.  I pulled it off and will take it to NAPA.  I shimmed the alternator as much as I could. I adjusted the adjustment bolt as much as possible and I am still ever so slightly riding up on the inside of the pulley. it is the closest I have been but just slightly out of alignment.  When I run a stick across the pullies they appear to be aligned, I am not sure if I should try to  change the shims on the a/c as it was never removed.  The belt will run up on the lip of the AC pulley and then go back into the track , I am close but not enough to call it done.

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I

Have you confirmed that there is no axial movement in the pulleys (A/C, tensioner, Crankshaft) that you are trying to align to.  There may be the slightest amount of movement in any of the other pulleys when the engine is running.

Jim

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I bought a new belt today.  The old belt, which had 10 hrs on it, has wider grooves from wear than the new out of the box belt. I will install it tomorrow and check if it stays on the pulley.

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I checked all the pull-ups and there is no play.  I am not even starting the engine only turning it over. It's still riding up on the lip of the AC pulley on the engine side.  I am using the new belt.  I am not sure what to do next.  I have 2 shims in that move the ALT almost 1/4". 

Again, it's a Lecee-Neville 160A alternator.  I have bought a new tensioner pulley and installed it, took idler pulley off and inspected it, and installed new belt.  I also installed the 2 shims.  

I may be installing the ALT incorrectly some how. It only goes in one way for the bolts, but I may be aligning it incorrectly somehow in respect to the tightening process.

the top bolt controls the angle of the ALT, the bottom bolt controls the fwd and aft alignment.

 

joe

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Is the A/C pump above the alternator or below it? If below I would ckeck the idler pulley under the A/C this may cause the belt to ride up on the A/C. Also is the A/C straight, and not tilted down a hair? if the belt is riding up the pulley while being turned by hand, there is a major mis-alignment. Is the belt routing correct and not trying to run over a bolt or bracket. I have found quite a few different mountings and roures, not sure what you have.

Gary

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