Volvo Penta Drive Belt - Lots of dust and quickly wearing??

[Lou C]

So I spoke to one of the local mechanics and he might think that it could be my two AMPS that might be drawing to much Amps for the Alternator which is causing it to eat up my belts. I am running a Fusion SG-DA41400 and a Rockville Atom 8m. My current alternator is stock and runs up to 70amps. So not sure if that could be the cause any thoughts on this?

Well it could be that, I would put an amp clamp on your Alt output to see what it is putting out, you may need a higher capacity alternator. If it is being pushed to max output all the time that could be it.

 

[Scott Danforth]

Run without music for a few days to find out

 

[Donald0039]

I think fellow boaters would appreciated less draw from your amps in the form of music not so loud.

A refrig probably draws more than your amps if you have a 12V one.

A 70 amp alternator will only put out 70 amps at a certain RPM range.

If you are really drawing a 70 amp load then not sure how long a 70 amp alternator will last.

It has to be one of a few things. Alignment or rusty (not smooth) pulleys or slipping belt. If slipping belt then tensioner is suspect if belt is right size and routed properly.

 

[alldodge]

Have not heard of that happening, but then again I never tried running that size amps

The fusion is 1400 watts 80A fuse recommended
The Rockville is 3500 watts 80A fuse recommended

 

[CaptnO]

Well it could be that, I would put an amp clamp on your Alt output to see what it is putting out, you may need a higher capacity alternator. If it is being pushed to max output all the time that could be it.

Yea I am going to buy an Amp Clamp today at Harbor freight and run some numbers.

Run without music for a few days to find out

Yea a boat without music is a no go for me, unfortunately.

 

[CaptnO]

Amp draw from alternator looked fine at 35-40 Amps this was me idling and stero at max volume.

 

[Grub54891]

Have a look at the crankshaft pulley. I’ve had one that was wore but not rusty. It would eat belts. Took awhile to figure out.

 

[Scott Danforth]

you may only be drawing 44 amps at idle because that is all that the alternator has with the engine at idle speed. most alternators do not put out their rated power until the engine they are bolted to is spun well over 1100-1200 RPM (when the alternator itself is spun over 3000 RPM)

look up the alternator curve. https://www.google.com/search?q=mando+70+amp+alternator+output+curve

at idle the alternator will only be putting out about 50-55% of its max rating

bring the RPM's up to 1500 RPM, then check. I bet you are pulling closer to 75-80 amps

you are pulling too much power from that alternator and the belt is slipping.

 

[ripjmk]

I wrote the following about a year ago but I can't remember how to insert a link to an old thread so I just copied it. If your bracket is the same as mine I'd recommend checking it out.

"I have a 5.0 GXi-E if your alternator bracket is the same as mine I believe it is a design error by VP. I machined the bracket to correct the situation, no more belt failures or piles of belt dust. First thing is to find out just how far alignment is out. The front flange thickness of the crank, power steering pump and alternator pulleys are not the same so care has to be taken to get the correct measurements The way I did it was :
1. Place a straight edge across the crankshaft pulley and with a caliper measure the distance from the straight edge to the first peak between the first and second groove of this pulley. This is your datum measurement.
2. Then holding straight edge across the crank pulley in line with each of the other pulleys in turn, measure the same distance from the straight edge to the first peak. This will tell you true position of the pulleys to each other.
3. Check the pulleys for being parallel to crank pulley. Place a straight edge, in turn, across the alternator and power steering pulleys and measure gap on near and far sides of the crankshaft pulley. Difference in the gap of either side of crank pulley indicates the degree the pulley being measured is out of parallel. Then do the same between the alternator and power steering pump.
With this information I found that my bracket was 1/4" too far forward (alternator cannot be moved forward or back). The bracket was at a very slight angle and the power steering pump pulley was slightly too far forward.
However, the belt tensioner was in the correct position relative to the crank pulley! I can't imagine how the designer of this bracket got it so wrong!
To correct the situation I machined the aluminum bracket bosses that the mounting bolts pass through. I removed 1/4" from each of the three bosses on the back of the bracket. I installed the bracket and alternator and checked alignment, I found it needed one S.S. washer between the engine and the bracket at the lower bolt to correct for parallel error. I then had to make a 1/4" spacer to put under the tensioner to bring it back to the correct position and it needed a longer bolt. Checking the power steering pump showed it was now 1/8" too far aft. I had to buy a PS pulley puller tool to move it into alignment.
Quite an ordeal, but now I don't worry about belt failure or cleaning up all the belt dust."

 

[ESGWheel]

CaptnO,
I too was plagued with the belt wear and dust issue on my 2005 5.0 GXi-E. Was replacing the belt ½ way thru our short season out of caution. Was driving me nuts and caused another problem. Ultimately, I had several issues: alignment, bad pulleys (rust / worn) and a slightly out of concentric freshwater pump pully.

For alignment: initially did straight edge process as many have suggested but finally bought a Dayco Laser Alignment tool which showed I had parallel but misaligned pulleys (the power steering pump). This tool will also show out of parallel. A little pricy but was well worth it for me for my automotive work I still do.

For rust / wear: while I removed all rust the slight pitting left behind and overall pulley wear was still chewing up the belt. I eventually replaced all pulleys including tensioner and idler except the smooth freshwater pump pulley.

For the freshwater pump pulley: while dust generation significantly down with the above, I still had it and a bouncing tensioner just like in your video. The middle hole on the pulley fitting over the shaft of the pump is what centers this pulley. I found that the outside bell of the pulley (where the belt runs) was not running true to its center. Think of an egg shape, so the belt was getting tighter and looser as the pulley rotated thru its high and low spots. I was able to have a machine shop correct this vs. buying a new one that may have had the same issue. Tensioner still bounces (but is less) and now dust gone. Been running the same belt for last couple of seasons just to monitor wear and dust. So far, all good.

Ripjmk’s write up of how he found the bracket out of alignment is an excellent example of keeping at this until you find the issue and fix it. These brackets are still available if you determine it’s the root cause but do not have the machine shop resources.

Other problems due to belt dust to be aware of:

• The spark arrestor is now full of this dust. Remove it and do a thorough cleaning. Check your throttle body area as well.
• The MAP (Manifold Absolute Pressure) sensor on the intake manifold may now be contaminated and not responding properly. This issue manifested itself on my boat whenever I was coming off plane down to idle > the motor would stall 5 times out of 10. When I pulled the MAP sensor, I found it was full of that belt dust! Cleaned it up and stalling issue gone. Caution: these need careful handling and special cleaning spray.

Keep sleuthing and let us know when you finally solve this.

 

[CaptnO]

I wrote the following about a year ago but I can't remember how to insert a link to an old thread so I just copied it. If your bracket is the same as mine I'd recommend checking it out.

"I have a 5.0 GXi-E if your alternator bracket is the same as mine I believe it is a design error by VP. I machined the bracket to correct the situation, no more belt failures or piles of belt dust. First thing is to find out just how far alignment is out. The front flange thickness of the crank, power steering pump and alternator pulleys are not the same so care has to be taken to get the correct measurements The way I did it was :
1. Place a straight edge across the crankshaft pulley and with a caliper measure the distance from the straight edge to the first peak between the first and second groove of this pulley. This is your datum measurement.
2. Then holding straight edge across the crank pulley in line with each of the other pulleys in turn, measure the same distance from the straight edge to the first peak. This will tell you true position of the pulleys to each other.
3. Check the pulleys for being parallel to crank pulley. Place a straight edge, in turn, across the alternator and power steering pulleys and measure gap on near and far sides of the crankshaft pulley. Difference in the gap of either side of crank pulley indicates the degree the pulley being measured is out of parallel. Then do the same between the alternator and power steering pump.
With this information I found that my bracket was 1/4" too far forward (alternator cannot be moved forward or back). The bracket was at a very slight angle and the power steering pump pulley was slightly too far forward.
However, the belt tensioner was in the correct position relative to the crank pulley! I can't imagine how the designer of this bracket got it so wrong!
To correct the situation I machined the aluminum bracket bosses that the mounting bolts pass through. I removed 1/4" from each of the three bosses on the back of the bracket. I installed the bracket and alternator and checked alignment, I found it needed one S.S. washer between the engine and the bracket at the lower bolt to correct for parallel error. I then had to make a 1/4" spacer to put under the tensioner to bring it back to the correct position and it needed a longer bolt. Checking the power steering pump showed it was now 1/8" too far aft. I had to buy a PS pulley puller tool to move it into alignment.
Quite an ordeal, but now I don't worry about belt failure or cleaning up all the belt dust."

Is this the bracket you are referring too? https://www.cecilmarineonline.com/3...080-special-order-10-to-14-days-for-delivery/

 

[ESGWheel]

CaptnO,
If you have a 5.0 GXi-E (which I also have) then yes that is the bracket he is referring to. They are a good source of parts, usually at a good discount. Also consider a used one from ebay since it’s a crap shoot just now > ie there is no smoking gun yet so parts changing is a reasonable strategy given your situation. It’s painful I know as I changed every single pully in my struggles, including a new alternator even though in my evaluation it was not the issue. Also, here the link for the VP store that has good diagrams to validate part nos. VP Store If you have the GXi-E then then here is the refined link VP Store for 5.0 GXi-E

The bracket is under Electrical.

 

[dubs283]

How many batteries are you using?

Having a stereo system with a large amp drawing a lot of current from too small a source will cause the alternator to over work. I recommend at least one extra deep cycle battery in any amplified stereo setup, most cases two depending on additional house systems. The extra capacity/AH of multiple batteries alleviates the need for constant amperage supply from the alternator

Yea a boat without music is a no go for me, unfortunately.

Worked for a guy years ago that'd take a used boat in on trade and I'd perform the inspection. I'd note many fundamental safety/operational issues with the boat that at times included a faulty stereo head unit. He'd tell me to replace the head unit and mark it done.

Made me realize a lot of people see a functional stereo as more important than boat operation/safety. My only take is loud music won't save your life, ymmv

 

[CaptnO]

I wanted to bring this thread back to life with an update for the new season. Take a look at the old belt lasted about 100hrs with the new belt I am going to install today. Something is definitely chewing up my belt

 

[CaptnO]

CaptnO,
I too was plagued with the belt wear and dust issue on my 2005 5.0 GXi-E. Was replacing the belt ½ way thru our short season out of caution. Was driving me nuts and caused another problem. Ultimately, I had several issues: alignment, bad pulleys (rust / worn) and a slightly out of concentric freshwater pump pully.

For alignment: initially did straight edge process as many have suggested but finally bought a Dayco Laser Alignment tool which showed I had parallel but misaligned pulleys (the power steering pump). This tool will also show out of parallel. A little pricy but was well worth it for me for my automotive work I still do.

For rust / wear: while I removed all rust the slight pitting left behind and overall pulley wear was still chewing up the belt. I eventually replaced all pulleys including tensioner and idler except the smooth freshwater pump pulley.

For the freshwater pump pulley: while dust generation significantly down with the above, I still had it and a bouncing tensioner just like in your video. The middle hole on the pulley fitting over the shaft of the pump is what centers this pulley. I found that the outside bell of the pulley (where the belt runs) was not running true to its center. Think of an egg shape, so the belt was getting tighter and looser as the pulley rotated thru its high and low spots. I was able to have a machine shop correct this vs. buying a new one that may have had the same issue. Tensioner still bounces (but is less) and now dust gone. Been running the same belt for last couple of seasons just to monitor wear and dust. So far, all good.

Ripjmk’s write up of how he found the bracket out of alignment is an excellent example of keeping at this until you find the issue and fix it. These brackets are still available if you determine it’s the root cause but do not have the machine shop resources.

Other problems due to belt dust to be aware of:

• The spark arrestor is now full of this dust. Remove it and do a thorough cleaning. Check your throttle body area as well.
• The MAP (Manifold Absolute Pressure) sensor on the intake manifold may now be contaminated and not responding properly. This issue manifested itself on my boat whenever I was coming off plane down to idle > the motor would stall 5 times out of 10. When I pulled the MAP sensor, I found it was full of that belt dust! Cleaned it up and stalling issue gone. Caution: these need careful handling and special cleaning spray.

Keep sleuthing and let us know when you finally solve this.

I am going to try the alignment tool today and see what results I get.

 

[alldodge]

Check your tensioner
If to little tension the belt will slip some. Don't know what you spec is but maybe 1 inch max deflection at longest span

 

[CaptnO]

Got that laser alignment tool looks like my power steering pulley might need to go in some more. Is it adjustable? Also what would cause it to wobble the shaft that it's on?

 

[alldodge]

Depending on how close it is, the pulley can be moved in. A cheap pulley puller/installer can adjust

I'm seeing all pulleys are 5 rib but I'm not able to determine if they are the same width due to optics.

Are all pulleys clean and smooth

 

[ESGWheel]

Also what would cause it to wobble the shaft that it's on?

If the pully can wobble on its shaft, like it’s a loose fit on the shaft > that is an issue!
If the pulley is tight on the shaft but wobbles when you turn it (called runout > i.e. as the pulley is rotated it traces a back and forth profile (without the belt on, and you can turn the PS Pump easily by hand) that is also an issue depending on how much. Here is a video link showing runout on a PS Pump. This wobble causes a misalignment of the ribs with every rotation which will wear it down quickly. Here is how: imagine you are driving on a road that has a perfectly matched set of groves to your tire tread. You tire tread actually sits down in these groves. And then you constantly move the steering wheel back and forth just a little bit. It’s like that > wear city.

 

[Donald0039]

A dial gauge as each pulley is turned. After checking for the pulley being loose.