Replacement Drive Belt for 1975 WH C-100

[Farmer Forbes 8]

I would like some help regarding a replacement drive belt for my 1975 C-100 WH.

According to all the information I have read, the part number is 7473; however, this is way too tight, so I purchased a 93-9808, which is the part number of the belt currently on the tractor.  

The existing belt seems just fine, I just wanted to replace it to make sure I was getting the most out of my tractor while plowing and tilling.

 

In addition to what is the correct belt, I am a bit confused on how the belt is to run inside the sheet metal to help keep the correct tightness.

 

Any comments would be appreciated

 

Thanks in advance

 

 

[953 nut 62,980]

The Tractor Supply 82" X 5/8" Kevlar belt is what you need.  Some belts sold on the internet are a bit wider than 5/8" and don't work.

Edited October 27 by 953 nut

[Farmer Forbes 8]

Thanks for your reply and your service

[Handy Don 15,139]

The belt will run completely within the belt cover. On geared WH’s the clutch loosens the drive belt allowing closely adjusted stops or guides near the belt’s path rub it and stop it from turning. This permits the transmission to shift without grinding. The exact stop/guide setup is different depending on model and year. 

[Farmer Forbes 8]

Thanks Handy Don

 

How should the belt be positioned on welded piece (belt keeper). Top of belt under or bottom of belt over the top?

 

Does the clutch pedal need to be adjusted in any way to keep belt in place. 
 

Thanks

[gwest_ca-(File Mod) 11,839]

Transmission drive belt 78-7100 replaced by 7473 - HB x 81.9" or 5/8" x 81.9"

Single cylinder drive belt 93-9808 - HB x 82" or 5/8" x 82"

 

Very few service manuals were published but this is a good one that applies to many years.

 

[Farmer Forbes 8]

Ok, frustration has finally set in after many attempts to route this drive belt in the proper manner.

 

I purchased this WH C-100 in 2012 and the same belt, 93-9808 has been on it ever since.  I decided I wanted to replace the belt, so I purchased another 93-9808, which DOES NOT fit, even though it is the same number.  The new belt is way to tight and the gears grind.

 

Below are two photos.

The first is the old/original belt which appears to be the correct size; however, if I attempt to feed it into picture #2 and have the correct tension, it consistently jumps off the inside track or falls onto the bolt holder coming off the frame and then proceeds to chew up the belt.

 

I have searched form a diagram to give me details on how correctly attach the belt.

 

Any feedback would be greatly appreciated since I am at my wits end.

 

BTW, up until recently this tractor drove like a charm pulling a single bottom plow and 36" tiller

 

Thanks in advance

[Farmer Forbes 8]

Maybe I should have mentioned this is a Model 1-0391

[Handy Don 15,139]

The blue arrows below point to the drive belt "rubbing thingees” on your tractor at the clutch pulley and on the belt cover. Both seem to be ok. The worn paint and rubber residue on the belt cover tab indicate it’s been doing its job so far. This belt seems worn because the clutch pulley arm is nearly perpendicular to the lower belt path but the belt isn’t taut. The belt is also riding kind of deep in the clutch pulley--is should ride about 1/16” proud of the pulley edges.

 

(You do know, right, that belts do not “stretch” -- the sides of the “V” wear down allowing the belt to ride deeper in the pulleys so it’s path around them is shorter--it only seems like the belt lengthened?)

 

Part numbers on belts are a bit of a crapshoot. Manufacturers all interpret things a little differently. Measuring is the only sure way. Understand that even ½” in belt length can be critical. Lot’s of guys (me included!) will bracket the likely size buying one bigger and one smaller and return the ones that don’t fit. Tractor Supply takes unused returns, for example. So does the jungle site.

 

The pulleys on your machine look fine as far as they are visible in the image--no obvious rust or broken/bent parts. Good.

 

A too-small drive belt will pull the clutch pulley down and to the right and may cause the “stopper” flange to rub continuously. If the bearing in the clutch pulley is also a bit worn, the pulley can be pulled out of alignment with the extra force and voila, dropped belt.

Good luck! 

 

 

Edited October 28 by Handy Don

[Farmer Forbes 8]

Thanks Handy Don.

This is exactly the feedback I needed and will be heading to TSC to purchase a belt(s).

 

Have a great day

[Handy Don 15,139]

2 minutes ago, Farmer Forbes said:

Thanks Handy Don.

This is exactly the feedback I needed and will be heading to TSC to purchase a belt(s).

 

Have a great day

Also, should have mentioned that you should keep in mind that the belt rotates counter clockwise--the bottom span is the “pulling” part. That’s why the stopper tab is on the lower edge of the belt cover. 

[Farmer Forbes 8]

Handy Don

At what angle should the pulley arm be to the lower belt?

Use the face of a clock and give me the time where that arm should be pointing.

 

Thanks

[953 nut 62,980]

You may want to look at the other side of the Wheel Horse to see if the clutch spring needs to be replaced.

 

[Handy Don 15,139]

15 hours ago, Farmer Forbes said:

Handy Don

At what angle should the pulley arm be to the lower belt?

Use the face of a clock and give me the time where that arm should be pointing.

 

Thanks

I've never really looked at it that way!

If memory serves, here, the difference between when the clutch is engaged and disengaged is maybe 5-8 minutes or more.

Engaged it’d be at about 5-8 minutes after the hour (?)

The closer to vertical, the less tension being applied to the belt due to the geometry and spring function of the clutch mechanism.

The farther from vertical, the more the clutch idler pulley’s stop flange will engage the belt. 

The really critical test is being able to both firmly engage and disengage the clutch and have the belt be stopped when disengaged. 

Edited October 29 by Handy Don

[953 nut 62,980]

Clutch pedal up

Clutch pedal down

[Farmer Forbes 8]

Thanks to everyone who provided feedback and pictures; they were most helpful.

 

Tractor is running again after purchasing an after-market v-belt, which by the way was 84 x 5/8 inches.

It appears the inside diameter of the belt was more important than the outside circumference.

Gears shift fine and I was able to finish my fall plowing.

[Handy Don 15,139]

4 hours ago, Farmer Forbes said:

Thanks to everyone who provided feedback and pictures; they were most helpful.

 

Tractor is running again after purchasing an after-market v-belt, which by the way was 84 x 5/8 inches.

It appears the inside diameter of the belt was more important than the outside circumference.

Gears shift fine and I was able to finish my fall plowing.

YW

 

17 hours ago, 953 nut said:

Clutch pedal up

Clutch pedal down

Looks just right from here.  Nice!

[gwest_ca-(File Mod) 11,839]

I wonder what is different with this tractor that it takes a belt 2" longer than the belt specified?

2" is a lot.

Larger pulley on the transmission?

Larger pulley on the engine?

Has a rear frame repair lengthened the wheelbase?

Today's belts do not stretch so it can't be that.

The internal cords in the belt can break and allow a belt to stretch under tension but the cords have to all break at the same location. Have heard of it happening and it was a real head scratcher for a while.

[mrc 1,014]

i'm with gary on this one.   

 

something has to be different when a hydro belt (84 incher) works on a gear jammer (82inch)

 

 

[squonk 44,859]

Someone had the tractor with the worn out  93-9808 82" belt  and original engine pulley. Either they replaced the engine with one off of a hydro or just used the hydro pulley because the original pulley got damaged trying to get it off, they wanted to "go faster" or they were too cheap to replace the belt and had the bigger pulley laying around IMHO.

 

 

 The engine sheet metal is all the same so the engine could be a 12 or 14 and using the original sheet metal would hide that. Measuring the engine pulley will give some clue.

[Farmer Forbes 8]

I appreciate you guys digging into this further and will certainly take a look at the pulley system.

 

After doing some research and the work I completed to get the tractor back running, the culprit might be the transmission pulley.

I see both the engine and idler pulley are 4'; whereas the transmission pulley is 6.5".

 

I will measure them to see if the pulley size might be the issue.

There were no other modifications to the tractor and the Kohler engine lines up with 10hp based on the model/serial numbers.

[Farmer Forbes 8]

As they say in the NFL, after further review, all pulleys are the correct size and no modifications were made to the tractor to lengthen the wheel base

I am as puzzled as everyone else.

 

I was able to measure the transmission and idler pulleys, but not the engine unit since I am not gong to take everything apart again since the tractor runs just fine, but from what I remember, it appears to be the correct size.

 

Thanks for all the comments.

 

 

 

[Lee1977 7,455]

A 5 1/4" hydro engine pulley will require an 84" belt on an 8 speed. I would check to see if the belt is rubbing the belt guard at the front with the belt tight.

If it's rubbing it will destroy top side of the belt.  

[Farmer Forbes 8]

Thanks Lee1977 for this information and for your service.

 

Today I took the time to remove the PTO and measure the engine pulley.  It is 4 inches, just like the idler pulley.

The transmission pulley is 6.5 inches in diameter.

The 84 x 5/8" belt is the correct size that allows the gears to shift easily and move the tractor.

Unless someone has other details about the size of each pulley, I will use the 84" belt.

 

Based on a visual inspection of each of these pulleys being painted with WH red, I am assuming they are all OE.

 

Thanks for the note about checking the belt guard.  There is a small amount of distance between the guard and the belt so it should not wear out too quickly.