04-17-2013, 05:53 AM
Gang,
When I bought my 03 with a C-12 Cat engine two years ago from Newell, it slung its serpentine belt off while I was on my out of Miami. Back to Newell. They advised to go to Fabick Caterpillar in Joplin. That is the start of a very long story that involves many trips to Miami and a couple to Joplin.
The good news is that the problem has now been found and fixed!
My symptoms were: 1) Belt wanted to "ride up" on some of the pulleys. 2) Belt would sometimes just break. 3) My AC compressor would kick on and off and when On the belt would really flop around. (like the compressor was pulling too hard). 4) The belt (or pulleys) squeaked when the engine was running.
Newell / Fabick replaced (over time) replaced all of the pulleys and the tensioner. Problem would seem better and then would return.
Yesterday at Thompson Caterpillar in Birmingham, I believe the problem was solved once and for all.
It turns out that there were many problems all combining to create this issue. Here are the problems in (my ranking) in descending order of severity.
1) The wrong tensioner was installed when the engine was installed in the Newell (10 years ago). The old tensioner which was a custom application (would hit its limit before taking all the tension out of belt. The new one (correct one for C12) has much more turn radius to take more tension out.
2) There was a subtle nick in the Alternator pulley that was grinding one of the grooves from the belt. (nick was filed off).
3) All of the problems with belts had filled the "teeth" of pulleys with old rubber making for less friction and more slipping.
4) The replaced pulleys were not installed with bearing "centerers". The front bearings on the two large pulleys were free to wobble around the bolt that holds them on.
5) One of the large pulleys had a completely bad bearing.
The long and short of this episode is that its actually pretty simple to diagnose belt problems. (at least for a Cat with serpentine belt).
1) take belt off and hand turn the pulleys by hand. They should turn easily and you should not feel any "grinding". If you spin them they should gradually slow down and not stop suddenly. If not suspect a bearing problem.
2). Closely inspect the teeth on the pulleys. (any nick or rough spot will gradually sand down your belt).
3). Check the operation of your tensioner by ensuring that it is not hitting the stop on the tight side.
4) Check the operation of the belt with the engine AC compressor on and off. In my case, the belt was fine if the compressor was off. If the belt flops around a lot during operation, you have a problem to find. Do not accept advice from anyone that says this is "Normal" for this engine. I still can't believe that I bought that one.
5) Using a long metal ruler ensure that all the pulleys are parallel and in the same plane.
Going forward...I have learned a few lessons:
1. Draw a belt routing map and keep it near the engine. My engine has lots of pulleys and such and a map will help you put a belt back on if it breaks.
2. Keep a spare belt with you at all times.
3. Inspect your belt and pulleys carefully. I was once running with a 7 groove belt instead of the normal 8 groove belt. (The other one had been ground off).
4. I dont believe that belt replacement is on the Newell maintenance checklist...but it IS on mine. My belt will now be replaced once / year.
Hope this helps someone.
Cheers,
bill
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When I bought my 03 with a C-12 Cat engine two years ago from Newell, it slung its serpentine belt off while I was on my out of Miami. Back to Newell. They advised to go to Fabick Caterpillar in Joplin. That is the start of a very long story that involves many trips to Miami and a couple to Joplin.
The good news is that the problem has now been found and fixed!
My symptoms were: 1) Belt wanted to "ride up" on some of the pulleys. 2) Belt would sometimes just break. 3) My AC compressor would kick on and off and when On the belt would really flop around. (like the compressor was pulling too hard). 4) The belt (or pulleys) squeaked when the engine was running.
Newell / Fabick replaced (over time) replaced all of the pulleys and the tensioner. Problem would seem better and then would return.
Yesterday at Thompson Caterpillar in Birmingham, I believe the problem was solved once and for all.
It turns out that there were many problems all combining to create this issue. Here are the problems in (my ranking) in descending order of severity.
1) The wrong tensioner was installed when the engine was installed in the Newell (10 years ago). The old tensioner which was a custom application (would hit its limit before taking all the tension out of belt. The new one (correct one for C12) has much more turn radius to take more tension out.
2) There was a subtle nick in the Alternator pulley that was grinding one of the grooves from the belt. (nick was filed off).
3) All of the problems with belts had filled the "teeth" of pulleys with old rubber making for less friction and more slipping.
4) The replaced pulleys were not installed with bearing "centerers". The front bearings on the two large pulleys were free to wobble around the bolt that holds them on.
5) One of the large pulleys had a completely bad bearing.
The long and short of this episode is that its actually pretty simple to diagnose belt problems. (at least for a Cat with serpentine belt).
1) take belt off and hand turn the pulleys by hand. They should turn easily and you should not feel any "grinding". If you spin them they should gradually slow down and not stop suddenly. If not suspect a bearing problem.
2). Closely inspect the teeth on the pulleys. (any nick or rough spot will gradually sand down your belt).
3). Check the operation of your tensioner by ensuring that it is not hitting the stop on the tight side.
4) Check the operation of the belt with the engine AC compressor on and off. In my case, the belt was fine if the compressor was off. If the belt flops around a lot during operation, you have a problem to find. Do not accept advice from anyone that says this is "Normal" for this engine. I still can't believe that I bought that one.
5) Using a long metal ruler ensure that all the pulleys are parallel and in the same plane.
Going forward...I have learned a few lessons:
1. Draw a belt routing map and keep it near the engine. My engine has lots of pulleys and such and a map will help you put a belt back on if it breaks.
2. Keep a spare belt with you at all times.
3. Inspect your belt and pulleys carefully. I was once running with a 7 groove belt instead of the normal 8 groove belt. (The other one had been ground off).
4. I dont believe that belt replacement is on the Newell maintenance checklist...but it IS on mine. My belt will now be replaced once / year.
Hope this helps someone.
Cheers,
bill
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Bill Johnson
Birmingham, Alabama