Alternator Double Pulley Long Term Review Results

T

Tom Katzenberger

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Jun 26, 2019
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Guys,

I have a double pulley which I have not installed on my 100 amp. alternator. I have been going through Alt. Belts lately and am thinking it maybe time to install the double pulley on the alt.

I didn't install the pulley because some members have complained of Power Steering pump belt slippage, as the belt wrap on the PW STR pump pulley is reduced when the double pulley is used.

I have been reviewing some old posts, to include Bruce H's, where people have been running double pulleys with success. I was curious what are the final thoughts on the use of the double pulley?

Thanks for any and all opinions.

Take care all,
Tom K.
 
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Jared,

It is the starter motor which powers the York 210 air compressor. That thing uses a lot of amps. When it kicks on the volts drop to below 11. I think the torque required to power the starter motor loads up the Alternator and causes the belt to slip. As the belt wears the problem gets worse until the belt fails.

The guys who are good with electric know better then I.

On the aircraft we tie a belt to the engine so that when we have a failure in the field we can cut the safety wire and slide the belt forward on the pulley without having to remove the prop.

I was thinking of doing this with the GMC on the RT66 Run, but also looking at the double pulley install if it truly helps.

Thanks Jared.

Take care and give Steph our best.
 
Why don't you just replace the v-belt pulley with a K6 flat ribbed pulley and install a K6. All of your belt troubles will disappear.

Balmar has the pulleys for all belt variations, but they recommend belts like the K6 for the more powerful alternators.
 
K6 Pulleys open up a whole new can of worms. I'm simply trying to solve 1 problem. I'm afraid this will make more. I believe the water pump rotation is one of the issues.
 
Tom Katzenberger said:
Guys,

I have a double pulley which I have not installed on my 100 amp. alternator. I have been going through Alt. Belts lately and am thinking it maybe time to install the double pulley on the alt.

I didn't install the pulley because some members have complained of Power Steering pump belt slippage, as the belt wrap on the PW STR pump pulley is reduced when the double pulley is used.

I have been reviewing some old posts, to include Bruce H's, where people have been running double pulleys with success. I was curious what are the final thoughts on the use of the double pulley?

Thanks for any and all opinions.

Take care all,
Tom K.
Click to expand...


Tom are you using industrial belts or automotive?

Try belts from Grainger. For the 455 I used A46, A56, A61 belts. They have the correct width which will not bottom out in the pulley. Total cost was under $50 and they have held up well.
 
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Todd,

I follow your previous thread and went and got A series belts as you listed.

I have a double pulley floating around here.But i'm going to use the a series belts and see how they work out. I want to make sure the coach can make it to California and back.

You and Sue take care hopefully we will see you sooner than later.
 
I have had a double alternator pulley for probably 15 years and 90,000 miles. If the belts are not tight, I sometimes get some slippage on my PS pump, but only at idle. Overall, I have been very happy with the system. I use heavy duty belts (Goodyear 17580) and they work just fine.
 
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I also had a slippage issue with my single belt 100A alternator. Especially after a night of boondock camping when the batteries were down. My amp gauge would show 80-90A charge for a short period of time and the belt would squeal. I found that the belt was too narrow, and bottoming out in the pulley. I went to an industrial belt that was 1/16 inch wider. the belt then stood slightly proud of the top the pulley. Slippage is now gone no matter how much current the alternator is making. I carry a spare of that belt, but so far no problems for 20K or so miles. Just what I experienced.
 
Tom Katzenberger said:
Thank you Carl. I just don't want to trade one slippage problem for another slippage problem.
Click to expand...

There are also combiners now that wait until the chassis battery is full before starting to charge the house battery.

This would be an advantage of the fancy ($) DC/DC chargers, you could limit the amperage and slipping of the belt if it's at the limit of the alternator.
 
Larry,

That was my current plan with the double pulley laying in the backfield for future use if needed. I took Todd's advice and got the industrial "A" series belts and I purchased a second alternator belt. I was thinking of tying the spare alt belt behind alternator pulley against the engine. If I have a failure on the road I can just slip it forward over the pulley.

At this point , i'm going to install the industrial a series belts and see what happens. Thank you guys for all your help.

Tom K.
 
Guys,
As I'm installing the belts I realized I got AX57 and the "AX" series which are cogged industrial belts.

I initially did this because the cod series were made for smaller pulleys.

Does anyone have experienced with cogged belts versus straight belts? Just trying to see if I jumped the gun and screwed up.

I'm going to install what I have now because I have a weekend available, but it would be a nice to know if I will be installing another set soon.

Thanks for sharing any experiences.
Tom K.
 
Guys I started the belt swap only to find out I have a double pulley on my power steering pump. If the stars align this will put 21 third wraps on the power steering pump and two wraps on the alternator. This will eliminate the squeal on the alternator with a double pulley , and the squeal on the power steering pump with a double pulley. The only downfall is I'll have to come up with another belt measurement for the double pulley on the power steering pump.

Has anyone run into this? It could be a very good thing. Just a little more work.Installing the double pulley on the alternator and coming up with the belt measurements.
 

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I think you're on the right track for a solution, Tom, but I would reinforce the comment earlier about rechecking your pulley alignment. When I helped Emery Stora replace his engine he pointed out the ¾ inch spacer on the alternator bracket opposite the alternator itself. When I got home I found that my coach was missing this spacer so I substituted a stack of washers. In the process I discovered that because of no spacer, my coach had a minor but detectable misalignment of the alternator belt that I had completely overlooked. Excessive belt wear hadn't been a problem but occasional squealing had been. Problem solved. The lesson for me was that many years of maintenance sometimes result in things getting out of whack, and that pulley alignment is more subtle than I knew.
 
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My alternator belt would squeal in the morning even though it was the correct belt and it seemed awfully tight. After installing the dual pulley and matched belts (important) I haven’t had a problem.

K6 flat pulley, you say? I think the old girl may need some new jewelry!
 
Doug,

Yes, I will spend some time on alignment of the pulleys.

This seems to be the best solution considering all things. I will be out there on my own in regard to belt length.

It should be less stress on the bearings, more contact area on the pulleys and hopefully reduced belt wear, belt tension and belt stress. I should have a small degree of redundancy and a longer belt life.

I hopefully will be installing (3) double pulleys on Monday (my coach alternator and 2 spares). Then off to belt sizing followed by a camping trip over the weekend. The A/C compressor will be the only unit single wrapped.

If anyone sees something coming at me on this mod please pop a flare.

As always, thank you all for your time, experience and wisdom.

Stay healthy and take care,
Tom K.
 
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The PO of my 1978 403 royal installed the double pulleys on the alternator and power steering pump.
Not sure if it was part of the plan, but the AC and the double pulleys all use the AC size belt. Very convienent
 
Applied GMC

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