Help with mower. Stops moving forward

StangOne50

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Hello everyone. Im having an issue with my mower. First here are the specs..
2007 Craftsman 12.5 HP 30" Hydrostatic drive Model 536.270340. Its pretty clean and maintained as far as oil,plug, fuel and air filter.

The issue I am having is that I can drive for about 20 seconds and it just comes to a stop. It does not shut off, just stops moving forward. To get it moving again I have to put it into reverse, drive for a second then I can push the speed lever back to the forward position and it will drive again.
It happened whether the blades are engaged or not and been happening since last week or so.

Things I have done or tried so far..
-I adjusted the clutch 2 turns. After this I still have the same issue except that it drives a bit further before it stops.
-I visually inspected the upper idler pulley and belt and they seem to be moving fine. While running if I press the clutch it loosens the belt and it tightens when I release the clutch pedal. I sprayed a little wd-40 on the idler pulley arm just incase.
-I drove it making sure the clutch spring was fully disengaged and when it stopped moving I checked underneath and can still see the pulley and belt spinning and when I move the speed lever into the forward position I can hear the sound of straining a bit.
Should I try tightening the belt even more by adjusting the clutch? It seemed I could still turn the adjustment bolt but I dont know how far to go with it.
-I let it run up on jackstands and the wheels did not stop turning.

One thing I noticed is that the clutch pedal does not fully disengage when the pedal is released. There is a spring that does not seem to be pulling it back fully.
Here is a photo of the spring after I press and release the clutch...
qUXpkVK.jpg

And another photo of the spring in the position it should be when the clutch pedal is released...
sI56QbU.jpg

Now Im wondering if it is simply this spring causing my problem by not fully disengaging the clutch. Is it safe to spray this area down with wd-40?
This is the belt which looks ok to me...
a186MiT.jpg
 

BlazNT

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That is the brake. Do not spray it. I have nothing else to add. I just did not want you to lose your brakes.
 

StangOne50

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That is the brake. Do not spray it. I have nothing else to add. I just did not want you to lose your brakes.

Thanks. I did end up spraying the spring area as it was sticking. Its actually still sticking even after I sprayed it. Im not worried about the brake. I dont even know why this mower has a brake pedal. its an automatic and speed is controlled by the speed control lever. I can easily push it to neutral and it comes to a stop.
 

BlazNT

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It is a parking brake. Not everyone has level ground.
 

StangOne50

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I would pull the wheel off the axle shaft and check for a sheared axle key on both sides

I did pull the back wheels off and the keys looked ok.
I pulled off the idler pulley and drive belt today. The pulley is in good shape. The belt was slightly frayed but idk if it looks bad enough to be causing my issue. I will try to post pics of the belt.
Im expecting a new drive belt today.

Here is the old belt, dont look too bad but do you guys think this can cause slippage?
KTpysFb.jpg

51Ftx1x.jpg
 
Last edited:

Rocky J

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Belts pull from there sides not the bottom and the bottom does not look like it has been slipping or any spot looking burnt from spinning. There is also a key in the pulley on top of the trans-axle you could suspect. Are you going up hill when it quits moving ? Does it do it when you first start mowing when it is cold from sitting ?
 

StangOne50

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Belts pull from there sides not the bottom and the bottom does not look like it has been slipping or any spot looking burnt from spinning. There is also a key in the pulley on top of the trans-axle you could suspect. Are you going up hill when it quits moving ? Does it do it when you first start mowing when it is cold from sitting ?

I removed the pulley last night and it seemed fine but did not notice any thing that would be a key. Its just a pulley with a washer. It happens when I am driving on more or less flat ground, maybe a bit bumpy but flat. Also happens after its been warmed up and without the blades attached.

I got the new belt on but its raining here so cant even test it out. In my manual it shows an adjustment for the clutch and says adjusting it will tighten the belt but it does not seem to have any effect on the belt tension. Someone told me on another forum that the belt will only be as tight as the spring allows but I feel like it can be tighter.
 

Rocky J

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Is it possible your release did not shut completely last time you used it to roll it around not running? Maybe if it still does it next time out you can pull it out and let it slam shut, Is the fan in good shape on your hydro unit ? Mine lost a few blades and let the oil get hot making it condensate then foam up and would quit pulling after 15 minutes, but it quit forward and reverse until it cooled for a few minutes. I drained out the oil, put in new and a new fan blade and never had the problem again, The air and water did not compress enough to pull it. If that pulley was slipping there should have been shiny metal dust around that area.
 
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