# Mower deck trouble - Sparks & smoke & thrown belt



## GoMopar440 (Aug 12, 2011)

I just got a used Craftsman mower (17hp/6spd/42"deck, model#917.27*0*710) late yesterday evening. It had some pretty chewed up blades on it so I swapped them out with a set of brand new mulching blades. The right side mandrel pulley was also bent enough to throw the belt so I pulled it off, straightened it out and bolted it back up. It was too dark to do anything else so I put it away for the night.

Today I took it out and started cutting down my way overgrown yard. It did really well for quite a while (went through a tank and a half of fuel), but as I was finishing up the front yard, all heck broke loose. It made a bang and loud scraping noises (motor still running, blades still turning) so I hit the clutch and leaned over to see what was happening. Then I saw sparks and smoke coming from on top of the mower deck area so I immediately disengaged the blades and shut the engine off. After looking at the top of the deck, The first thing I saw was that the belt laying loose and chewed up (it was fine before I started mowing) and then I found this piece laying on top of the deck.

























Can anyone tell me what this thing is? It has a pad on it that looks like a brake pad of some sort and the opposite end is sheared off almost like it was cut through by the edge of one of the pulleys. 

I cleared the grass and routed the belt back onto the pulleys to see if I could figure out what went wrong. The belt wouldn't tighten up anymore when I engaged blade lever and I still can't see where the broken part came from. I've got a owners manual, but there isn't a parts diagram in it to try to find where the broken part came from. I'm not sure exactly how to remove the deck yet but I'm sure I can figure it out eventually. A service manual would make the job a lot easier, but I haven't been able to find one online yet. Any ideas where to look for one?


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## wjjones (May 28, 2010)

Welcome to the Forum!..GoMopar440.. Its a brake arm that stops the blades from turning when you disengage the deck...The other end of this part should still be on the deck around the pivot arm that engages the blades. I think your model# is off a digit or something i couldnt get it to pull up either.


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## GoMopar440 (Aug 12, 2011)

I took the model number to the local sears and they pulled it up on their system. (yea, there's a typo in the first post. It's 917.27*0*710). We found out that it was indeed the brake arm (it's just a LOT shorter now. LOL!), but it looks like it goes to the side opposite of where I was looking at. I ordered a new brake arm and while I was there I also picked up a new deck belt and mandrel pulley since they had those in stock. They also printed out a copy of the parts diagram for the deck for me, so at least now I have something to work with.


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## jhngardner367 (Apr 5, 2011)

From the looks of the rusty area in the middle of the break edge, I'd say it was already cracked,and probably dropped and caught the belt,which ripped it the rest of the way off. Better check the other side,as well.


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## GoMopar440 (Aug 12, 2011)

Must just be the lighting or my poor picture taking skills. There's no rust at the break. The broken edge is freshly ground/scraped metal all the way across. 

I'll be trying to drop the deck this weekend and I'll be able to get a better look at the other end of the messed up part at that time.


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## jhngardner367 (Apr 5, 2011)

Yeah,it could be.looks like a reddish tint,so I assumed it was rust.Reflection of the background,maybe?Either way,it must have had a crack started,that wasn't noticed. If the belt won't tighten anymore,itcould have taken out the tensioning spring,too.It's a common thing for those springs to break.Check it against the parts diagram,to make sure.


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## GoMopar440 (Aug 12, 2011)

The red stuff looks like the brake pad material that rubbed off from use and then settled in the bend. The metal at the break is mostly silverish with some blue and brown color from the heat of whatever chewed it up.

Thanks for the tip about the return spring. It does sound like that may be part of the issue. I'll make sure to check it over when I get it apart.


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## wjjones (May 28, 2010)

GoMopar440 said:


> I took the model number to the local sears and they pulled it up on their system. (yea, there's a typo in the first post. It's 917.27*0*710). We found out that it was indeed the brake arm (it's just a LOT shorter now. LOL!), but it looks like it goes to the side opposite of where I was looking at. I ordered a new brake arm and while I was there I also picked up a new deck belt and mandrel pulley since they had those in stock. They also printed out a copy of the parts diagram for the deck for me, so at least now I have something to work with.



Keep us posted on your repair....Also when you have it torn down put some grease between that pivot arm, and washer thats under it..


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## GoMopar440 (Aug 12, 2011)

Wow! It's been a while since I've even been able to look at the tractor. Going to College full time and the new (to me) house and shop projects all got pushed up front. Well today I finally made time to work on fixing the mower deck. It didn't take too long to figure out how it was attached after jacking the tractor up and setting it on jack stands so I could see and work under it. 

After I dropped the deck and pulled it out, the first thing I noticed was that the deck has *two* of those brake arms on it. And sure enough, both were broken off in the same manner. 









Upon closer inspection I discovered the reason why the outer pulleys had ground the ends of the brake arms off. The center bracket that holds the two inner pulleys had broken away from the deck at the rear weld and the mounting plate was bent upwards almost an inch at that point. The brake arms were rubbing on the bottom edge of the outer pulleys. Once the pulleys finally cut the brake arms completely off, that was when the deck alignment got too far out of whack and made all the ruckus I heard.

Both of the brake arms, washers and springs were removed along with the right side outer pulley. Then to fix it I ground the paint off the deck, as well as the center pulley mounting plate, around where the weld was. I fired up my little 110V MIG and rewelded the center plate back onto the deck where it was originally. I put probably 50% more weld on there that what was put on by the factory. It may not be the prettiest weld (flux core wire w/o gas), but it won't be going ANYWHERE any time soon. 









While I had it apart I spent a little time cleaning the dirt, grass and rust off the deck so I could put some fresh paint of it. Unfortunately, windy days with a dusty barn for a shop lead to messed up paint jobs. At least it's coated completely enough to prevent it from rusting for awhile longer anyway. 

Reassembly was just putting everything back together in reverse order. 









I still need to receive the second brake arm from Sears and install it before I can call it 100% done. Would I be able to run it with just one brake arm until the other one comes in? If so, would it be better for me to have the brake arm installed on the left side instead of the right?

















I'd really like to be able to cut the grass and mulch the leaves before the snow starts to fall in the next day or two up here. It will probably be at least a week before the new brake arm will arrive.


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## wjjones (May 28, 2010)

Glad to hear you got it fixed up, and it looks pretty good to me...


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## GoMopar440 (Aug 12, 2011)

Thanks for the words of encouragement! 

I decided to modify one of the old brake arms to help control the center pulley pivot plate travel. The arm on the left prevents it from being able to over travel and let the right side arm travel past the end of the plate and bind up.

To make a temporary fix I shortened the one of the broken arms to remove the edge that was cut off by the pulley. I made sure to leave the notch there for retaining the spring hook end. When I bolted it back on then I had to limit the travel of the arm with some stiff wire to prevent it from rolling out of the slot in the pivot plate. I tested good on the bench so I bolted the deck back onto the tractor. 

I took it out afterwards and tested it out by engaging and disengaging the blades with no grass under it. Everything sounded good so I drove it around front and cut the front yard. It cut ok and didn't make any wierd noises. It's actually sounding the best it ever has since I've owned it. 

Now I just need to set the deck alignment and figure out what's binding the deck height adjustment lever. I can only get about 1" of down travel from the full up position. It didn't matter so much today as the grass had gotten so tall I needed to run it with the deck up high anyway.


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## wjjones (May 28, 2010)

Does yours have the height adjusment knob for presetting cut height?


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## GoMopar440 (Aug 12, 2011)

I'll have to look to see if it has the height adjuster knob. I didn't notice one on there before, but I wasn't looking for one either. 

I'd really like to find an owners manual for this thing for stuff like this. It doesn't have the standard LT/GT designation most people refer to for this body type, so I can only use the model # to find stuff for it.

However, snow has started falling so it's already been put away for the season. I'll work on the deck adjustments when I pull it out next spring. 

Many thanks to those that offered tips to help me fix this.


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## wjjones (May 28, 2010)

You can use your model# to get the manual part# off searspartsdirect and then I bet you could find a manual on ebay, etc.. I am not sure if yours is the same , or not but mine says 1.5 to 4" on the cutting height. The manual says point blades forward for front to back adjustment, and point them to the side for side to side adjustment.. Measure from the blade tips cutting edge to the ground/ floor.


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## dangeroustoys56 (Jul 26, 2010)

I had to do that to my 99 weedeater tractor- most my stuff has bolt on brackets- while craftsman has the weld on ones - and of course since it was well beat, most the brackets had stress cracks.


I took some small pieces of steel and welded gussets and the brackets to the deck to help stabilize them and keep them from cracking again.


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## wjjones (May 28, 2010)

Yep the deck I bought recently had a broken bracket for the lift I got a shoppe to re-weld it, and while they where at it I got them to re-inforce the other brackets with some extra beefy welds..


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