4" "Speed up" Pulley Question
 

Hello all. I have a 129 with a 44" deck and want to install a 4" pulley
to replace the 5" . What size belt would this require ? What would
the IH part number be ?

Thanks in advance .

Hydrocub

I'm not feeling the love here ... sniff , sniff

I don't know that IH ever made the "speed up" pulley set for this deck. I have heard of their existence, but can't find any info in any of the parts books. If there is such a thing, it would have either been an afterthought and may be a reference in a SB, but it didn't make it into any books. I think they were all "custom made". You may be on your own.

I assume your using a 44a? Should be the same belt as used for the 50a in this post from a few days ago. Overdrive Pulley

Bill

Thanks guys ... I feel better now . Berwil , thanks for the info . My thinking
is that of Bedell in that if you are going an inch smaller in pully diameter
one would need to decrese the belt size by one inch . J -Mech , a few guys
on here have gone to a smaller pully on this size deck and have been
happy with the results of a faster deck speed . The 4" pully is an IH part,
just not not advertized as an option .

Thanks all,
Hydrocub

That is correct.......:ThumbsUp:

Like I said, I am aware of the pulley's existance, but not their origin. Roland also confirmed that they are not IH. If you think they are, then get us a part number. I'm certain you will find they are not IH. Mathematically speaking, the belt will need to be more than 1" shorter. You guys all realize that you by going to a 4" pulley from a 5" pulley you are increasing the RPM by 720RPM right? :bigthink::bigeyes::bigeyes::bigeyes: That's a LOT! Better watch it! I think your asking for trouble. Just my :TwoCents:

Mine has the 4" pulley. I get a better cut and discharge. I love it.

There's no doubt in my mind that that is true. But anytime you increase speed by that much...... WOW. I'm sure the bearings are made for that much speed, but are the spindles? How about that big center blade?.... It's been a while since I've used one of those old deck, but I never thought they were all that bad as a stock set up. Oh, sure, the newer style decks do a better job. But really all you are doing is making it so you can increase your ground speed. Again, just my two cents.

So far mine has been like that for four years now. Mowing 3/4 acre. I have yet to see any negative side effects. If there is any I would love to know what to keep a eye out for,

My only concern is if you hit something. Might break a blade, or snap a spindle. Other than a safety issue, or a equipment failure (bearing) I don't think there would be any "negative" effects. I'm sure it cuts much better.

I see cc specialties sell them, part #126393C1.
cub cadet still has them also,46.00
so they do make them, but they are not made for the older pre 1972 decks.

the deck serial # break for the pulley change is 81741 and lower big pulley# 59-703-c2 ,81742 and above small pulley#126-393-c1, the part numbers may have changed but the small pulley was factory on the quiet lines.

Ok. After using the part numbers you guys listed, I see it now. It makes a difference how you look up the deck. I just went to the parts for the deck through the tactor, and it only listed the one pulley. I understand now.

Now, for as often as this question comes up, can we PLEASE put the info in the tech library under implements so we can just reference the question there when it comes up again. PLEASE!! :beerchug:

Actually it is the difference in the circumference of the pulleys. Half in this case since the belt wraps half of the pulley.
5* pie /2 = 7.84
4* pie /2 = 6.28
diff = 1.57
Numbers will change with the depth the belt actually rides in each one.

Hey I just want to return to the subject for a moment. I retract my statement about the new speed with this pulley being a problem. For whatever reason, I was picturing (in my mind) the 42" deck, with the big center blade. I realize now, it's the later style deck (44" duh) and I see no reason for any concern. After all, they later used that pulley on that deck with absolutely no issues.

Now, here's my questions:
*Doesn't the later pulley require the 5/8" drive belt? Or is that just the 756-3007?
*So, there are 3 drive pulleys for the 44/50" decks. 126393C1, 59703C2, and the 756-3007? Is that correct? That's what I see. They are all 3 listed under the respective sub models (44/50, 44A/50A, and the 44C/50C) What happened to "B" anyway..... :bigthink:


Tim,
I did the math earlier and got the same answer. (Not questioning you, just sayin. But I have a cool app on my phone that does it cause I'm lazy. :biggrin2::biggrin2:)

Well Mr J :biggrin2: I have a few of those 4.750" pulleys, not the same as a 4" on the early 48" decks,not sure who put them on there but they are the same color as the deck.They take a 1/2 belt also for the deck and the 3/8 belt for the pto.I think the B looks more like an 8 so they skipped it.

The investigation continues....

When I worked at the local IH dealer 40+ years back I saw a disastrous result from overspeed.

The owner had somehow managed to make/have made a custom "speed improvement kit". As I sort of seem to very vaguely remember, the center pulley set had been modified to about a 3 or 3-1/4 inch PTO/center spindle pulley, and the spindle to spindle pulley must have been about a 8-1/2 or 9 inch. Also the pulley on the PTO clutch had been sized up...don't remember the size.

Welllllllll.....the owner hit something solid with the deck. It was a 1250/44A combo. Left edge blade had one side broken off, with that piece embedded in the deck shell, and other side of that blade bent at about a 45* angle. Spindle shaft was bent as well, and a BIG chunk out of the center blade. Customer was howling when told the price of repair....
All new spindles, all new blades, PTO pulley, center spindle pulley stack and labor.

If you need the speed improvement kit, stick with what IH designed. It works well, and is within safety limits.

Hi all ,
Sorry it took so long to get back here . 14+ hr work days are taking it's
toll . BTW , I love a good back and forth " intelligent" discussion .
To respond to some questions and thoughts :

" larger center blade " ? Nope , all the same size .
" IH never made this pully " ? IH 26393-C1
For the 1250 " disaster " , well , gee , about a 2" + reduction ? Not what I'm
talking about .

The below response is more about my line of thinking as "I rnt vry eduktd in sifrin "
I can however manage 2+2 and such . Past ten fingers can be a challenge .

"Actually it is the difference in the circumference of the pulleys. Half in this case since the belt wraps half of the pulley.
5* pie /2 = 7.84
4* pie /2 = 6.28
diff = 1.57
Numbers will change with the depth the belt actually rides in each one. "

Thanks ......


" just to increase your ground speed ? " No , just looking for a cleaner cut
in higher grass .


BTW , I am currently running the stock set up which is a 5" pulley running a
IH 59971C1 belt I believe with a 44 " U -1111 deck on a 129.

The question is .... what would be needed in a IH belt . A part number for
the application is what I'm looking for.

Another thing , If I have offended anyone it was certaintly not my intent .
I have been " on " for 24 hrs and have to go back in the morning .
I'm a little "punch drunk" and probably shoudn't be behind the wheel of this computer .


Again ,
Thanks guys

Hydrocub

Maybe 20-25 years ago, I bought a 4" pulley to use on my 44A deck. It was listed in the printed parts book under "what" I do not remember but I've seen it. The pulley is for a 1/2" belt. When I bought the pulley, I also bought a new belt and it fit perfectly. I don't remember the part number and the tractor is not here so I can't look.

You can call Donnie at Jacobi Sales (parts), 812 364 6141, and he can tell you what you need to know. I'm not sure the other two parts guys could help you.

The 4" pulley was referred to as a "speed up" pulley by the parts guys. Don't know if that was the counter guy's term or IH nomenclature.

I would like to see all this sorted out and put in the tech section also. Mike

The below response is more about my line of thinking as "I rnt vry eduktd in sifrin "
I can however manage 2+2 and such . Past ten fingers can be a challenge .




If I am barefooted, I can manage a 20-count. :biggrin2: :biggrin2:

This belt/pulley information would make a very good "sticky note" in the tech reference section. As I sort of seem to very vaguely recall, IH named the kit as " blade speed improvement kit"; it contained a different center spindle pulley stack and a belt.

My 38A deck does have a bigger center blade, not sure about others in the xxA/xxC series.