8N 12V Conversion pulley size issues

[drmath]

I converted my 1950 8N to a 12V system a few years ago and am glad I did it. However, even though I bought the kit to do the conversion using a Delco alternator, the brackets provided didn't align the alternator pulley with the water pump and crankshaft pulleys on the tractor. Since I tried to do it without removing the loader, and time was short, it was difficult to work on and I finally got it close and called it good.

Now my crankshaft pulley (which I knew was worn when I did the conversion, but let it go due to lack of time) needs to be replaced so I removed the loader and dismantled the tractor. Now that I can see everything clearly I decided to further modify the alternator mounting in order to align the pulleys, but here is what I've found. The front of the pulleys are lined up pretty well, but all 3 pulleys are different widths with the alternator pulley being the narrowest by far. With the set up I was running, the fan belt was rubbing on the fan behind the alternator pulley which, of course, pretty much destroyed the belt.

As long as the tractor is apart, besides the bad crankshaft pulley I'm going to replace the water pump since it will never be easier than now. I'm hoping the 2 new parts have identical width pulleys, but I'm assuming the alternator pulley will still be much narrower than the other two.

Did I miss a step in the conversion saying that I had to install a different pulley on the alternator? I was under the impression that a Delco alternator was a bolt on option. After I get the new parts installed I need to modify the alternator mounting bracket to improve the alignment, but do I need a different pulley for the Delco alternator?

I did some searching of the archives but haven't found this particular issue discussed. I'd appreciate any advice/experience anyone has to offer.

 

[Hobo,NC]

98-NAA5825 pulley would be the correct pulley for a 5/8" belt that's it bar none the right pulley for the application... Understand this its the ONLY! one for your application that's correct...

 

[drmath]

(reply to post at 19:59:10 02/03/21)

Thanks! The need to replace the Delco pulley explains a lot. The self-proclaimed "experts" I talked to before attempting the conversion never mentioned this.

 

[Den N Ms]

Drmath This great site has them.

Click here
ALTERNATER PULLEY

 

[jimtrs]

If you haven't got the new crankshaft pulley yet, be sure to get the one that matches your FEL pump's stinger shaft. That is if you indeed have a front mounted pump.

Any new water pump and front crank pulley for the N series will have 5/8 wide pulley.

Your local Starter / Generator shop is also a good LOCAL source for the correct alternator pulley. Easy to change with an impact gun, otherwise you may muck up the alternator fan trying to hold it. The impact gun just blips the nut off & back on.

 

[Hobo,NC]

What it should look like with a 5/8" belt installed if the belt sets deeper than the O.D. of the pully its WRONG. The world is full of so called fixed universal 5/8" X 3/4" pulleys there is no such thing its either for a 5/8 are a 3/4" inch belt. The O.D. on this one is just shy of 2-1/2".

I can not get the belt pulled in tight its close tho.

https://forums.yesterdaystractors.com/viewtopic.php?t=1401220&highlight=pulley

 

[drmath]

(quoted from post at 03:53:25 02/04/21) Drmath This great site has them.

Thanks!

 

[drmath]

(reply to post at 05:43:16 02/04/21)

I already ordered the new crankshaft pulley, but I waited until I had the old one off so I would know what I needed before ordering.

I do have the front drive hydraulic pump on a Wagner loader. In addition to the pulley, I ordered a new hydraulic pump drive hub since the old one had been patched up a number of times over the years with heater hose, sleeves, etc. I felt replacing the crankshaft pulley and drive hub at the same time, and from the same vendor, would give me a better chance of having compatible parts.

Thanks for the tip.

 

[drmath]

(reply to post at 06:26:33 02/04/21)

Thanks again. I have to remember to begin any project with the 8N by going to this forum. You guys are a great help!