# Craftsman drive belt idler tension



## RickH (Feb 9, 2014)

I have a Craftsman 24" 5 hp model 247.886640. My neighbor borrowed the machine while I was at work and the auger belt broke. He attempted to replace it and in the process put the auger pulley on upside down. Needless to say, the auger pulleys didn't line up correctly. I finally got that figured out, but now snowblower won't go forward. It works in reverse with some hesitation and sometimes moves about an inch when I have it in a forward gear. The tires spin in forward when I lift them off the ground. The drive belt spins as long as I don't have the engine engaged (i.e. the traction grip lever closed). The drive pulley continues to spin, but it appears the drive belt does not have enough tension to move the rest of the drive train. There is a spring that is attached to a hex bolt on the engine at one end (see pics). It appears that the other end is supposed to attach to the idler pulley bracket, but attaching it this way puts no tension on the spring, and, even if it did, the spring would be pulling the idler pulley away from the belt and create less tension. The last pic shows that end of the spring that is through the hole in the bracket with the end of the spring resting on the drive belt in the idler pulley. The parts manuals have not been helpful with this. It would make sense for the spring to go from the idler pulley bracket to a connection on the engine to the right of the bracket, but there doesn't appear to be any place for this. Any help with this would be greatly appreciated.


----------



## Sid (Jan 31, 2014)

That belt is definitely installed wrong, and probably the wrong length. Take a look at your manual, or google your model #, and you may even find a you tube that shows how to install that belt.
Sid


----------



## motorhead64 (Dec 15, 2013)

I see a hole in the chassis (on the left) in one of your photos that looks like it might be the anchor hole for one side of the idler spring.? MH


----------



## RickH (Feb 9, 2014)

Sid....That is the original belt. As far as I can see from youtube videos about installing a new belt, it is installed correctly....but I'm very open to finding out why it's not installed correctly....But it's the original belt.


----------



## Shryp (Jan 1, 2011)

Yea, that belt closest to the engine is not suppose to be wrapped around the larger crankshaft. Also, your third picture shows a spring connected right to the idler pulley and almost looks to be digging in to the belt. Definitely wrong there too. If he broke the auger belt what was he doing messing around with the drive belt? Also, you don't have to remove any pulleys to change a belt. Just start the belt on and pull the rope a little bit.


----------



## RickH (Feb 9, 2014)

Motorhead64....That hole is for screw to the shield that covers the motor. I believe that hooking the spring to the left of the idler pulley bracket will pull the pulley away from the belt and loosen the tension.


----------



## RickH (Feb 9, 2014)

Shryp....The drive belt is around the friction wheel disk and the drive belt pulley. I think the problem...or at least part of the problem...is with the spring for the idler tension pulley. Right now the one end is connected to a hex nut that is attached to a non-moveable part of the engine, and the other end is through a hole in the idler tension pulley bracket with the hook digging into the belt. I know that's got to be wrong and I think, somehow, the tensioner spring needs to be pulling the bracket to the right to push the idler pulley into the drive belt to add tension to the drive belt. The way the spring is set up now makes no sense, but I that's how it was when I got it back from my neighbor.


----------



## Shryp (Jan 1, 2011)

The first thing you have to do is get that belt closest to the engine under the crankshaft. You can worry about the spring after that. Once the belt is corrected that idler pulley is going to move a good 6 inches further over and you will probably be able to find where the spring goes.


----------



## RickH (Feb 9, 2014)

Thanks everyone for your help on this. It turned out that I had the idler pulley on the wrong side of the drive belt. All of the youtube videos on belt replacement showed the drive belt idler pulley on the left side. Once I put it on the right side, the spring on the idler pulley bracket pulled it to the left, against the drive belt, giving the needed tension to the belt and and engaged the rest of the drive train. It all seems so obvious in hindsight.


----------



## Carbazol (Dec 11, 2020)

Not sure if this forum will help 6 years later...but I've got the same problem with my drive belt tension spring now. It broke and i cant tell where it hooks....is it supposed to be pulling the wheel towards the right against the belt? Any help is greatly appreciated.


----------



## Craftsman2 (Oct 12, 2020)

Yup the idler should tension the belt. The drive belt should have permanent tension unlike the auger belt which is tensioned on demand from the handlebar.


----------



## Harb43 (Jan 25, 2021)

Yes, the spring should pull the idler arm to the left and press against the belt. (Left/right as seen from the operator's position at the handlebars.) On my machine, on the left side-plate just below the front of the engine there's a small notch and a nearby small hole where the hook on the end of the tension spring goes. The straight part of the hook comes out through the notch and the tip of the hook goes in through the hole. I had a problem in which a burr on the side-plate stamping was sawing through the hook as the engine vibrated. I went through two hooks in my first winter of use. Current spring in place since 2008!


----------

