# Mower blades will not totally dis-engage of Craftsman 42" rider



## WildcatKY

I just rebuilt the deck on my Craftsman 42" riding mower, 917.271550, (new everything) and now the blades will not totally stop when I dis-engage the Clutch Lever. I was careful to re-assemble it according to the owners manual. All parts underneath seem to be moving correctly. When I engage the clutch lever, the pulley that the clutch spring is attached to moves backward and does tighten up the belt and the blade rotates okay. So, I assume the clutch cable is okay. It's when I dis-engage the clutch lever, the blades do slow down but do not totally stop. They still rotate at a pretty good clip. The only thing I did notice was that the brake arm pad did not pull away from the mandrel pulley about a 1/2" when dis-engaged. It's like there is still too much belt tension on the pulleys, keeping the blades from stopping. Any ideas?


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## paulr44

WildcatKY said:


> I just rebuilt the deck on my Craftsman 42" riding mower, 917.271550, (new everything) and now the blades will not totally stop when I dis-engage the Clutch Lever. I was careful to re-assemble it according to the owners manual. All parts underneath seem to be moving correctly. When I engage the clutch lever, the pulley that the clutch spring is attached to moves backward and does tighten up the belt and the blade rotates okay. So, I assume the clutch cable is okay. It's when I dis-engage the clutch lever, the blades do slow down but do not totally stop. They still rotate at a pretty good clip. The only thing I did notice was that the brake arm pad did not pull away from the mandrel pulley about a 1/2" when dis-engaged. It's like there is still too much belt tension on the pulleys, keeping the blades from stopping. Any ideas?


*The only thing I did notice was that the brake arm pad did not pull away from the mandrel pulley about a 1/2" when dis-engaged.*

I don't understand. When dis-engaged the brake arm should BE AGAINST the pulley. What you're suggesting is that the brake arm isn't against the pulley when dis-engaged, therefore it is ineffective.


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## WildcatKY

paulr44 said:


> *The only thing I did notice was that the brake arm pad did not pull away from the mandrel pulley about a 1/2" when dis-engaged.*
> 
> I don't understand. When dis-engaged the brake arm should BE AGAINST the pulley. What you're suggesting is that the brake arm isn't against the pulley when dis-engaged, therefore it is ineffective.


Paulr; Sorry for the confusion; I meant to say, the brake arm did not pull away from the pulley when engaged. It is against the pulley when dis-engaged. It's like the pulley that the clutch cable spring is attached to is not moving back enough to push the brake arms out when engaged. I hope this is a little clearer.


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## dehrhardt

It sounds like something in the idler system is binding and not allowing it to function properly. When the belt is tensioned, the brakes are supposed to come off automatically as the idlers move.


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## Sir Thomas

A new system may not fit EXACTLY like the old one so you have to adjust for that. Is there an adjustment nut somewhere in the system? Probably like a nut on a shaft to adjust a tenson? There is a delicate balance between the tensioner and the brake pad. If both are pressing on the belt and pulley, it could burn the belt up. You said all new parts. Did you put a new belt on? If so, double check that belt against the old one. Belt sizes are specific and the slightest difference can make a difference. Even a quarter to and eight of an inch. Also check the width and depth of the wedge in the belt. Another thing you can check is the condition of the valley in the pulley. Is it smooth or rough. If the pulley is new then the new surface may be causeing some binding.


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## 30yearTech

It's very likely the cable that applies tension to the idler arm assy. If the idler arm moves freely, the cable is probably dragging. I would replace the cable. If the arm is free to move.


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## WildcatKY

Sir Thomas; Yes, new pulleys and belt. I did not notice any adjustmant nut anywhere. I took the deck off and re-checked all of the idler moving parts and the engagement clutch cable. They all moved correctly and showed no signs of wear. I did notice when I put the new belt on (that came with the kit ) that it was a 'tad' smaller than the original belt that came with the mower. Original belt is 12 years old. So, I put the old belt back on and everything is working properly now. I figured that the old belt had stretched from 12 years of use and just assumed that the new belt would work properly. I guess one should never assume anything. I have not cut yet this spring, but will be cutting in a few days. I will post later after I cut. Thanks to all for your suggestions.


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## Sir Thomas

The rider is over 12 years old? There is probably several areas where there is wear and tear. I was trying to look at the diagram. There are no cables involved are there? How is the brake/clutch engaged? I see a tension spring. Was that replaced? I guess what I'm saying in a machine that old, not everything is as tight as it used to be so going to the next size up woud be the best thing unless replacing the spring is an option. Let me know how is goes.


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## 30yearTech

Sir Thomas said:


> There are no cables involved are there? How is the brake/clutch engaged?


Look Again!!

There is a cable, reference # 152, and there is a return spring to pull the idler arm back. If the cable is dragging or the return spring is missing, then the blades can continue to turn or creep. Unless the wrong belt was supplied, the issue was not due to a new belt needing to be worn in or "stretched".


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## Sir Thomas

30yearTech said:


> Look Again!!
> 
> There is a cable, reference # 152, and there is a return spring to pull the idler arm back. If the cable is dragging or the return spring is missing, then the blades can continue to turn or creep. Unless the wrong belt was supplied, the issue was not due to a new belt needing to be worn in or "stretched".


Sorry I missed that. I did see the spring but not the cable. All the new stuff would have worked if this was a new or faily new maching but there are so many places that has wear and tear and it all adds up. It doesn't take much differential between the tensioner and the brake to stop the belt. Replacing the cable and the spring might have made some difference but the tightness (or lack thereof) of all the levers and guides can certainly dictate how effective they are. I grew up on 2 acres and when they first came out with lawn tractors (I'm almost 64) we were constantly rebuilding the tractors so I know. 
Dirt and grime gets into the pivots and wears the holes larger and you begin to get a lot of play. That what I mean when I say the system looses it's tighness.


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## 30yearTech

Sir Thomas said:


> Sorry I missed that. I did see the spring but not the cable. *All the new stuff would have worked if this was a new or faily new*


If this were a new or fairly new machine, the likelyhood of it having this issue would be very small.

If the OP is happy with the way his unit is working, then that's up to the OP. 


Sir Thomas said:


> there are so many places that has wear and tear and it all adds up. It doesn't take much differential between the tensioner and the brake to stop the belt


Go back and read the OP, the issue was not with the belt engaging, but rather with it not disengaging!

If the replacement belt was the *correct* one then there is another issue, and it's not *wear! *Wear will cause slipping not tightening. Using a belt with wear to fix this issue, is likely a sacrifice to some level of performance in the operation, as now slippage is a possibility. I am very familiar with the design of the mower in this post, you did not even know it used a cable to engage the system. Over time dirt and moisture enter the cable conduit and can cause the cable to bind and not release easily. The return spring on the mower decks often break and fall off, and can be overlooked as a reason for this type of problem. 


Sir Thomas said:


> Replacing the cable and the spring might have made some difference but the tightness (or lack thereof) of all the levers and guides can certainly dictate how effective they are. I grew up on 2 acres and when they first came out with lawn tractors (I'm almost 64) we were constantly rebuilding the tractors so I know.


I was offering suggestions as to what the issue might be, based on 40 years of experience. I don't do this as a hobby, I do this for a living. Like Paul we have worked on perhaps thousands of pieces of equipment over the years, and have attended factory service schools for a majority of the major manufacturers. We know the nuances of these machines and what to look at when they don't work right. 



Sir Thomas said:


> Dirt and grime gets into the pivots and wears the holes larger and you begin to get a lot of play. That what I mean when I say the system looses it's tighness.


I know your just trying to help, and that's what most of us on here are trying to do. I just don't want anyone with a similar issue to read this thread and think that they have to go out and purchase a new unit, or accept that it no longer will work correctly because their unit has wear and cannot be repaired correctly. 

If you understand how it works, then you will know why it's not working correctly. The setup on this unit allows for easy replacement of the idler arm and pivot washer should it have significant wear. The OP indicated that the deck was rebuilt and the idlers were moving freely. There is an adjustment on this unit to increase tension in the event of minor wear. I work on these units weekly and I know how make them work correctly, and what to look at when they are not working the right way!


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## jaybird62

ive found that this can be caused by wear on the idler arm from the rollers on the brake arms. the rollers wear a detent area into the idler arm and wont allow the engagement mechanism to fully disengage:wave:


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## Sir Thomas

Putting new equipment on a machine that old can create problems. Often you would have to replace the whole affected assembly. Like I said wear and tear and affect how the brake and clutch works.


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## 30yearTech

Sir Thomas said:


> Putting new equipment on a machine that old can create problems. Often you would have to replace the whole affected assembly. Like I said wear and tear and affect how the brake and clutch works.


Yes, I agree wear and tear can affect how the brake and clutch perform, but that does not mean it can't be fixed correctly.

*No, you don't have to replace the whole assembly* to fix something right, you just have to *Figure Out* what the problem is and address it. 

Anyone can take the shotgun approach and start replacing things until they get it right. Or as you suggest, replace the whole thing with a new one. If that's your best suggestion then that's not very helpful. 

The suggestion that jaybird listed is a viable item to address with the type of issue that the Original Poster was experiencing, on this mower design.

Here are some pictures of a similar mower deck I just worked on last week.
Deck1.jpg
This is the deck off of this 12 year old Craftsman riding mower
Deck2.jpg
Same deck with the debris cleaned off. The problem with this mower was the blades were hard to engage and would stall under a load. They were also very slow to disengage, if they would stop at all.
deck3.jpg
This is the return spring that pulls the the idler arm back to disengage the blades. Sometimes they break and fall off, they are often overlooked as a reason the deck will not fully disengage or is slow to disengage.
deck4.jpg
This was the issue with this mower deck, and is very common on this design. NOT WEAR, after I cleaned up the rust and corrosion, the idler arm was free to move to engage and disengage properly.
Deck5.jpg
These are the brake arm's Jaybird was referring to, they can bind and cause issues with the engagement and disengagement of a mower deck, although on this one, they worked fine.

After a good cleaning and an new drive belt, this 12 year old riding mower may not look NEW, but it works as good as a new one, because the problem was isolated and addressed, the customer is happy and they didn't have to purchase a new riding mower!


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## Sir Thomas

30yearTech said:


> Yes, I agree wear and tear can affect how the brake and clutch perform, but that does not mean it can't be fixed correctly.
> 
> *No, you don't have to replace the whole assembly* to fix something right, you just have to *Figure Out* what the problem is and address it.
> 
> Anyone can take the shotgun approach and start replacing things until they get it right. Or as you suggest, replace the whole thing with a new one. If that's your best suggestion then that's not very helpful.
> 
> The suggestion that jaybird listed is a viable item to address with the type of issue that the Original Poster was experiencing, on this mower design.
> 
> Here are some pictures of a similar mower deck I just worked on last week.
> Deck1.jpg
> This is the deck off of this 12 year old Craftsman riding mower
> Deck2.jpg
> Same deck with the debris cleaned off. The problem with this mower was the blades were hard to engage and would stall under a load. They were also very slow to disengage, if they would stop at all.
> deck3.jpg
> This is the return spring that pulls the the idler arm back to disengage the blades. Sometimes they break and fall off, they are often overlooked as a reason the deck will not fully disengage or is slow to disengage.
> deck4.jpg
> This was the issue with this mower deck, and is very common on this design. NOT WEAR, after I cleaned up the rust and corrosion, the idler arm was free to move to engage and disengage properly.
> Deck5.jpg
> These are the brake arm's Jaybird was referring to, they can bind and cause issues with the engagement and disengagement of a mower deck, although on this one, they worked fine.
> 
> After a good cleaning and an new drive belt, this 12 year old riding mower may not look NEW, but it works as good as a new one, because the problem was isolated and addressed, the customer is happy and they didn't have to purchase a new riding mower!


I bow out


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## Maytag

Yup Jaybird.....I have that problem on both of my 42" decks. One is 6 yrs old the other is 20+ yrs old. Just replaced that plate that has the detent in it and the wear mark is already coming back and causing a problem. Plate needs to be hardened a little bit.

-Maytag (oh God "He" is back?) :wave:


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## 30yearTech

Maytag said:


> Yup Jaybird.....I have that problem on both of my 42" decks. One is 6 yrs old the other is 20+ yrs old. Just replaced that plate that has the detent in it and the wear mark is already coming back and causing a problem. Plate needs to be hardened a little bit.
> 
> -Maytag (oh God "He" is back?) :wave:


I have found that a little bit of lubricant on the roller and arm helps.


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## jaybird62

there is kit, part # 151785 cam roller kit. come with new idler arm and 2 new brake arms. replace a lot of these every year


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## GoatDriver

If the ones we work on are not to bad, we take the plate apart as 30yearTech shows and clean it up real good with a twisted wire wheel brush on a 4 inch grinder, then repaint and and apply some good bearing grease to the mating surfaces of the plates and deck, replace the return spring and put it all back together. This has worked good for us over the past few years and saves the wait on parts and the customer a little $.


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## jaybird62

that's another viable option


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## bigcut

30year,
You have no idea how much your posting has helped me figure out what is possibly wrong. Mine is slow to disengage. If I drive it over some bumpy ground it will eventually snap the lever on the dash all the way down and the blades quickly stop. I suspect it is clippings, dirt, and grime. It may also be that the spring is weakening. Those pictures were immensely helpful. The parts diagram doesn't show the points of connection. 

I'm also 64 and not really getting any faster. Many thanks for your professional expertise. I could actually understand what you were saying. Many Thanks !!!
Bigcut (John Casper)


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## 30yearTech

bigcut said:


> 30year,
> You have no idea how much your posting has helped me figure out what is possibly wrong. Mine is slow to disengage. If I drive it over some bumpy ground it will eventually snap the lever on the dash all the way down and the blades quickly stop. I suspect it is clippings, dirt, and grime. It may also be that the spring is weakening. Those pictures were immensely helpful. The parts diagram doesn't show the points of connection.
> 
> I'm also 64 and not really getting any faster. Many thanks for your professional expertise. I could actually understand what you were saying. Many Thanks !!!
> Bigcut (John Casper)


You are Welcome! Hopefully you will also be able to get yours working correctly again. Best of Luck... :thumbsup::thumbsup:


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