Help- clutch pedal won’t move

[oldc105 2]

Was mowing normally on my C-105. Shut mower off to clear accumulated grass and put tractor in neutral but left engine running. When got off the tractor heard a metallic crack sound and then the engine stopped. Tried to restart engine but couldn’t move clutch pedal- engine barely turns now as if clutch is engaged- can change gears properly and able to roll/push tractor in neutral. Any ideas?

[SylvanLakeWH 25,577]

Odd...

 

Assess clutch rod and linkage for correct function. Is drive belt free or tight on pulleys? 

[oldc105 2]

Seems to be tight - it’s definitely not loose as far as I can tell until I take a better look tomorrow 

[wallfish 17,000]

I'm guessing the belt came off and wedged or something like that and maybe the idler pulley let go. metallic sound

The belt is the only connection between the engine and the clutch pedal. It would still change gears and roll in neutral plus a wedged belt would drag the engine down to stop

Pull the belt guard off and you'll probably find the problem

[953 nut 55,260]

Could be the running board got pushed in far enough that the clutch peddle is being prevented from moving as it should.

[oldc105 2]

Thanks all. I’ll check further today and advise on what I find 

[oldc105 2]

So now I know what’s happening but not why- here’s the explanation- the drive belt rotates towards the rear. With the clutch pedal depressed, the belt tensioner pulley is towards the front of the tractor and not engaging the drive belt. As the clutch is released, the tensioner pulley grabs the belt which then pulls the pulley back to the rear and it jams into the drive pulley, stalling the engine. The pulleys remain jammed together and rotating the drive belt backwards releases everything.  So WHY does the tensioner pulley do this? I’d think there should be a spring to prevent this but I haven’t seen anything- could something have fallen or broken off?

[oliver2-44 9,756]

A picture sure would help. Double check the manual for a belt routing diagram. When you say the belt is not always in contact with the idler that doesn’t sound right.  
Is the idler a flat or V groove pulley.

Is the side of the belt that is contacting the idler the same shape (flat) (V groove) 

I’m on my cell phone so not good for parts diagrams.
Also Study the parts diagram and you tractor to see if a spring or any thing is missing. 

[oldc105 2]

I forgot to add the pictures. The top picture is when the clutch pedal is fully depressed- the tensioner pulley moves towards the engine and the drive belt is loose. The 2nd picture shows the tensioner rotating toward the rear and as the belt rotates to the rear, as tension. Increases the belt pulls the tensioner to the rear and it jams into the drive pulley. I can’t find anything to stop the tensioner from going too far- perhaps a pin in the clutch pedal linkage has broken so the tensioner arm can rotate too far? The parts diagram shows the linkage as multiple pieces with pins connecting them. I can check this tomorrow. 

[wallfish 17,000]

The belt must be too long.

When the pedal is released the belt tension should have enough tension on it to prevent that idler pulley from going over the top and back that far back.  You shouldn't be able to pry it back that far with a proper set up. Was that belt changed recently?.

 

[Handy Don 12,232]

52 minutes ago, wallfish said:

The belt must be too long.

When the pedal is released the belt tension should have enough tension on it to prevent that idler pulley from going over the top and back that far back.  You shouldn't be able to pry it back that far with a proper set up. Was that belt changed recently?.

 

Definitely too much belt. It is in the groove at the engine drive pulley?

Wacky thought, but has the engine moved?

Edited September 19, 2023 by Handy Don

[peter lena 8,631]

@oldc105  would also consider the idler pulley itself to be part of the issue , small bearing failure /  is a regular issue , also verify every related movement point , gets penetrating oil , red spray crease , make the rust run out . you should also have a " helper "  operate the pedal to verify what's probably , going on , probably a combo , idler pulley , wrong belt , or binding linkage , preventing smooth easy engagement . seen that a few times . Pete 

[oldc105 2]

I can’t remember when the belt was last changed so maybe it stretched . Where can I find the length of the belt to check that? I’ll also check if somehow the engine moved. Coincidentally last week I was mowing and a torrential downpour started, and I had to drive fast into the shed- my foot slipped off the wet clutch pedal and I had to stand on the brake to avoid a collision - but if anything the front wheels bumped the wall- not the hood- but maybe that has something to do with this. Maybe that abrupt stop moved something or the belt stretched. I’ll see if the engine has moved but the belt length would help too. Any ideas on where to get that?

[peter lena 8,631]

@oldc105  belts don't  stretch , the side engagement area , wears ,leptin it drop deeper into the pulley  grove. that impact , might have an effect , look it over front wheel impact , could lead to sloppy steering , etc. look on the site for related  drive belt set up pictures . giving you a view  to how it should be , ex  wheel horse drive belt pictures . very simple set up , but it does require service ,now and then , Pete 

[SylvanLakeWH 25,577]

25 minutes ago, oldc105 said:

belt length would help too. Any ideas on where to get that?

 

5/8" x 83" 

AZ Tractor is where i got my last one.

http://a-ztractor.com/

 

[oldc105 2]

Thanks to all for help. I’ll continue investigation. 

[WHGuy413 2,689]

We are also dealing with a belt issue with my sons c-121. The belt that was on it was in need of being changed. Last night he changed it out for the correct belt (7473 from toro) and now his clutch pedal does not come back at all and the belt will not stop spinning. It seems too tight.  Today I had him take it all apart and we out the old one on and now the idler pulley goes all the way back and hits the drive pulley. Definitely stumped.

[Handy Don 12,232]

12 hours ago, WHGuy413 said:

We are also dealing with a belt issue with my sons c-121. The belt that was on it was in need of being changed. Last night he changed it out for the correct belt (7473 from toro) and now his clutch pedal does not come back at all and the belt will not stop spinning. It seems too tight.  Today I had him take it all apart and we out the old one on and now the idler pulley goes all the way back and hits the drive pulley. Definitely stumped.

Have you done a careful comparison of the two belts? 

Exactly the same length? 

Exactly the same width at the top and the bottom of the V? 

Exactly the same height? 

Wear no the sides of the old belt making it curve inward or exposing inner cords?

And by exactly, i mean to within 1/64th of an inch.

[WHGuy413 2,689]

11 hours ago, Handy Don said:

Have you done a careful comparison of the two belts? 

Exactly the same length? 

Exactly the same width at the top and the bottom of the V? 

Exactly the same height? 

Wear no the sides of the old belt making it curve inward or exposing inner cords?

And by exactly, i mean to within 1/64th of an inch.

We got our issue squared away tonight. Upon further inspection the rod that goes through the frame from the clutch side to the idler pulley was not the correct way. A previous owner along the way must have installed the belt that was on it and then welded the piece that the clutch rod pushes and pulls to make the idler rock, into place but unfortunately it was the wrong place. I noticed it when I took a spare one off the shelf and saw how much different they were when assembled. We had to cut the old rod to get it out and install the one I found on the shelf. After that the brand new drive belt (part number 7473) fit perfectly. Alex reassembled the rest of the tractor and took it for a test spin and it works great. Way better than it originally did. 

[Handy Don 12,232]

12 hours ago, WHGuy413 said:

previous owner along the way

With these 30-60 year old machines, some that have been through many POs, it can be an adventure of discovery.

Well done tracking it down!

Good fortune that you had a spare. I, for one, would have taken a long time to consider a modified arm on the clutch/idler shaft as the problem.

[oldc105 2]

Mine is finally FIXED!  So the belt was witn AND the idler pulley seized, so as soon I started to let out the clutch the idler pulley was unable to spin so it rotated rearward and jammed into the drive pulley. The worn belt helped that too. Thanks to all for the help. Now if I can only find a rear discharge mower deck - my side discharge is good but I prefer the rear- does anyone know if I could convert it to rear?

[Handy Don 12,232]

3 minutes ago, oldc105 said:

Now if I can only find a rear discharge mower deck

Shouldn’t be too difficult. 37” and 42” are both around. A-to-Z will have some in stock and go ahead and put a "want” in the forum classifieds or a visit to the Big Show!

[oldc105 2]

Great idea. Thanks