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JP56

Help With 312 & C100 -8 Tractor Drive Belt Issues

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JP56

I know there have been numerous posts on the subject of drive? belts (Engine to Trans), but I was up till 3:30 this morning until I was completely bleary eyed & brain muddled, trying to find what I need to know, so I apologize in advance for being so long winded on this.

 

Background: I have a 1988 312-8 I currently have a Transmission drive belt 78-7100 replaced by 7473 - HB x 81.9" or 5/8" x 81.9", on it. I ordered 2 belts from Toro that were supposedly  the proper belts for this 312, and also my 1975 C100. I looked the OEM belt numbers up & both defaulted to the same 7473 replacement belt. So I ordered 2 of them, but when they arrived, they had a completely different number on them from what I ordered. Thinking it was just another "Part Superseded by Part No Whatever", I put them aside until I could have time to work on both tractors. To my point: the belts do NOT fit, are way to small, so I tried an 81" too small, then the 83" too big, then found a post here that gave the actual size of the belt in inches & purchased one & put it on.

 

The belt fits, but seem slightly larger than it should be with a bit too much slack in it. After browsing here & finding many posts about the problems find & installing the right size belt, and a few pics of the CRAPPY Toro exploded parts viewers that show belt retainers, I got the belt on and tightened, but ended up with a LOT of Bouncing/Rattling of the Clutch Pedal, and some belt slapping sounds! Yesterday while using it, it became harder to shift & I just happened to look on the ground  & I see that the 3 & 7/8" long by 3/4" fine threaded bolt that goes thru a bracket under the seat had vibrated one of the nuts off & it just dropped out of the bracket.

 

RANT NOTE: before I found this web group & started really getting into my horses, I had purchased these tractors from 2 different SUPPOSED "collectors & restorers", which turns out to mean "self proclaimed experts" that just replace or Rube Goldberg a few parts in, slap some spray paint on them, then walk away counting your cash & having a good laugh afterwards! 

 

Back to Topics: I clean the part up & it is very clearly marked: ENDINE P/N SP5827. I cannot find this part on any IPL I have accessed, I have not seen a drawing or picture of it on any sites I have been to, nor have I found it mentioned in any "service" manuals I have accessed so far. I did google the part number & found that it is No Longer Available, & that mine appears to have actually been damaged & tampered with before I bought the tractor, since the photo of it shows that there should be a shaft sticking out of the center at one end of the threaded shaft,  that I think is supposed to ride in and out as the top of the clutch rides against it. I saw somewhere that it may possibly called a Clutch Shock Absorber. 

 

Questions:

On the 1988 312-8

1) What Exactly is this part ?

2) What Exactly does it do ?

3) Is it Absolutely Necessary ?

4) Is there Any Alternative Part that can take its place ?

 

On both the 88 312-8 & the 75 C100-8

Does anyone have or can anyone post pics of the drive belts in place on the side of the tractors that show the belt routing, all brackets and guides & retainer rods near pulleys?  

I saw one pic here of the tensioner pulley/bracket like the one on my C100, and it appears to have a guide bracket on the right side that actually stops the belt from spinning when you depress the clutch, and mine does not have that, & as I said, on my 312, the guide brackets seem to have been relocated or missing & that plunger type thing under the seat that fell out is definitely broken.

 

I sure hope I can get to the bottom of these annoying problems :angry-banghead: :angry-banghead:

 

Thanking everyone here in advance for any & all help I may get on this! This site has been great & a bunch of great guys here who have helped me tremendously to learn my way around horses!

 

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Goldnboy
Posted (edited)

In the files section for each model machine are pictures in the manuals for the belt guides for each tractor type they can be quite useful when you have head scratching moments. There are belt guides on the 312 and the C100 has guides on the belt guard.

Screenshot_20240627_121701_Drive.jpg

20200504_122411.jpg

Edited by Goldnboy
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Lee1977

Most of us just remove the shock absorber and just use the spring.

 

 

 

 

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JP56

Thanks for the great pics Goldnboy !

 

I do have some pics for both tractors in Manuals I downloaded over the years from this group, but none of those show this as clearly as the ones you have posted here, either on my monitor or if I print them out!

 

I will have to check the clearances on the guard on my C-100. I am pretty darned sure they are bent out much wider than what is spec'd out here.

 

As for my 312, I immediately noticed from the second pic here, that mine is missing the top belt guide! I have the second guide on the bottom of the pulley, but I am also going to check the clearance on that one also, but I am pretty sure it is a much bigger spec than shown in this photo. That only leaves the black bracket located in front of the pivoting idler pulley. I am pretty sure that my bracket is not located in the same spot as the one shown in the pic I just found & marked with a white arrow.

312 Belt Guid Bracket at Clutch Idler 2024-06-27 235256.png

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JP56
9 hours ago, Lee1977 said:

Most of us just remove the shock absorber and just use the spring.

 

 

 

 

Thanks Lee1977!

  

So if I understand correctly, that threaded shaft under the seat with the broken plunger shaft that is supposed to sit against the tensioner pulley bracket when it's in the rearward position, is pretty much an unnecessary part?

 

The spring you mention, is the pedal return spring under the footrest on the left side that goes from the linkage to the hole in the axle housing?

 

If that's the spring you mean, using the spring & relocating the belt guide bracket in the second pic to the position in the pic, should eliminate the vibrating/bouncing clutch pedal & belt slapping I am getting? (I Hope)

312 & C-100 Clutch Pedal Return Spring  2024-06-28 000953.png

312 Belt Guid Bracket at Clutch Idler 2024-06-27 235256.png

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Lee1977

If the hole in he frame where the clutch idler shaft goes through is worn you can get noise with the clutch push in. My C-129 would have a knocking sound with the clutch pushed in. 

I drilled the holes out to 5/8" and added brass bushings on the C-120. The PTO lever shaft got the same treatment. I used 5/8" OD x 1/2" ID bushings !" long and sawed them in half.

I have a 312-8 doing the same, but so far I haven't been able to remove the roll pin, some previse owner stored it out side before I got it.

SAM-0315.jpg

SAM-0311.jpg

SAM-0307.jpg

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peter lena

@Lee1977 as you know , many areas related to the belt driven set up , desperately need help  , typically belt vibration , is set up by iminent bearing failure , my frequent reference to tiny bearings / poor lubrication , also refers to a mower deck , the unsupported back  span is typically A BUZZ , with vibration , bet there is a related spindle hang up , starting / stopping , causing bounce . have also added   3"  FLAT PULLEY , TO TOP OF DECK IN THE MIDDLE OF THAT BOUNCE ZONE , enhanced every bearing , lubricant , detailed smooth function . none of my decks , have a screaming start , smooth , quiet , easy , also eliminated the PTO  brake pad , years ago , after cleaning out and regreasing  related bearings , its so solid , smooth , quiet , most of it  was functional detailing . firmed up / washers , 550 deg grease , gain more from a roller stool , study , as to  INTENDED FUNCTION , than anything , of course this is not in the book , but it sure does eliminate the problem . just a suggestion , pete 

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Ed Kennell

 

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