# GT6000 Mower Deck Linkage Failure



## DForal (Jun 30, 2011)

One year old GT6000. Was mowing yesterday when I heard a big bang and a large piece of metal comes flying out the chute. Scared the you-know-what out of me 

I was able to find the pieces on the ground and reconstruct the mower deck front linkage (see picture). Looks like the mower deck front linkage had a failure in the bolt holding the support bracket to the frame. The head-end of the bolt is still on the mower (trapped between the frame and the muffler - still in the hole in the frame). After the bolt failed, the front link and bracket went under the mower where the link was broken (at the cotter pin hole) and the bracket ejected out the chute.

After looking at the parts diagrams, it looks like the bushings that are supposed to support the bolt going through the frame are missing - that could explain why the bolt failed. In looking at the failed bolt, it appears to be a classic fatigue failure. The final failure area is a very small percentage of the overall bolt area, indicating relatively low loads.

I'm going to call Sears and get replacement parts and also ask for a new set of blades since they passed that large support bracket (some good impact marks on it). They've done a good job of supporting the warranty on this tractor so far, we'll see how it goes.

This is the third assembly problem I've "discovered" on this machine.

1. Mower Deck - wrong nut used
2. Gas Tank Reserve - pickups reversed
3. Missing bushings causing bolt failure (current thread).

All very simple, minor errors that caused big head aches for me. And, it is costing Sears a significant amount of money (the first problem needed a field call to resolve). I wonder what is next


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## wjjones (May 28, 2010)

My front link broke where it goes through the deck not the threaded end but the other. I ordered a new one, and it is grade 5 instead of grade 8. I have went over mine, and tried to beef up all the weak spots since then. I even rigged a chain so I could use the mower while I was waiting for the front link to get here. Believe it, or not it was 10 times easier raising, and lowering the deck with the chain holding the front up instead of the front link. I also took my deck to a welding shoppe, and got them to beef up all the bracket welds. I hope they get it fixed for you soon let us know how it turns out.


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## DForal (Jun 30, 2011)

Update: Called Sears and they are sending the parts needed to fix it. I asked for new blades, but they said they could only do that if someone came out to my house; I understand their policy.

I like Walter's idea about using a chain until the parts arrive. I may rig that up today or tomorrow and finish my mowing.

In looking at the broken bolt that is still captured on the machine, I'm not sure I can get it out or the new one in without taking the muffler off. Other than not taking the muffler off right after running the engine   are there any gotta's that I should know about? Thanks. Dave


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## txsteve (Dec 4, 2011)

Dave..
Open the hood and unconnect the wire connection to the headlights.Then close the hood and open it again 1/2 to 3/4 and pull straight up..now the hood is off..
Next two little bolts holding heat shield..
Next two bolts hold the muffler to the frame..You might to wiggle the muffler and pull down off the pipes..The pipes are just sticking into the muffler..You don't have to remove the pipes from the engine..

Have a jack ready because that broken bolt holds the front axle in place..so when you pull the bolt out,, the axle will drop down..so jack up just to hold the weight up off the axle..

What bushings are you missing??..I ask because those two bushings are in the axle..Those are swivel bushings in the axle between the C frame support..You don't see them till you pull the axle down..
Did the manufacturer forgot one bushing ?


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## DForal (Jun 30, 2011)

TxSteve, thanks for the detailed instructions; I did not know about taking the hood off.

Attached is a picture (exploded view) that shows some of the parts I need to replace (#66-70). Part number 66 is the bolt that broke. I could not find part 67 on the nut side and didn't see #67 on the head side at first glance, but it is hard to see up in there and it may be there.

Based on the drawing below, I don't see how that bolt (#67) supports any weight of the tractor. In fact, I can easily wiggle the bolt now - it is not supporting any weight. You must be referring to some other bolt or a different front end design.

I'm going to wait until the parts arrive before taking things apart; when I do, I'll report back what I found out. It is possible that the bushing is still in position and I just cannot see it and that the nut side bushing is laying the grass somewhere. Since the bolt broke near the nut, it seems that it would be the nut-side bushing missing that could cause that.

Thanks again for your help. Dave


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## txsteve (Dec 4, 2011)

Yes..#66 bolt is the pivot bolt that is the only bolt that holds the axle in there..
If you have the front of the tractor in the air and pull that bolt out..The whole front suspension will drop down and hang by and damage the rods #61 n #62..
So only lift the wheels off the ground like 1/8 inch or less..


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## txsteve (Dec 4, 2011)

The two front n rear #67 bushings are in the axle that are sandwiched between the frame support..You can see if they are there or not by looking between the axle front and rear between the frame...They look like a 1/8 thick washer..but those are part of the bushings your looking at..


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## DForal (Jun 30, 2011)

TxSteve, now I see what you are talking about - might be a bit tricky to get everything lined up when putting the new bolt in. Looking more closely at the aft side of the cross-frame member, there is visible damage (ovaling of the hole) in the frame member (1st photo taken from right side of tractor looking inward and forward). It appears that the bolt was directly in contact with the frame - supporting a root cause of missing/broken bushing - do you agree? The aft bushing should be seen in this view, correct? I'm wondering if I dare repair the unit as planned without addressing the damaged frame member? What do you think? I'm concerned that if I make the repair and then there is additional damage or failure in the future, my warranty might not be valid. BTW, the frame has a 5 year warranty.

The second photo (right side of tractor looking inward and aft) shows the front of the frame cross member with the pivot bolt hanging out and up against the muffler.


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## txsteve (Dec 4, 2011)

What you can do is remove heat shield n muffler...deck too because you have to check the spindles n blades..
Use something like a 2x4 under the frame rails and just lift the weight off the axle..

Then pull the broken bolt out..
Then jack it up slowly so the axle comes down just I little so your see the holes are free but the axle is still in the C frame so the axle stays in the channel...

Take the broken bolt and put it in the rear hole and see n feel if the hole got egg shape or very wear too big..
I say the broken part of bolt that has the shoulder..Not the threaded part..The shoulder is bigger than the threads..

If the front n rear holes are ok and not too sloppy..Just wait for the new bolt..

If you feel the hole(s) are too big due to loose bolt wearing the holes..Call Sears and their tech will call the shot..

If he feels its abuse..you pay the trip..If he feels it from a loose bolt from manufactured and in time the bolt wear the hole big..You might get a new tractor on Sears..No charge..

If you feel the holes are ok..When you put the new bolt in..Make sure you tighten that bolt very tight..

It will squeeze the C channel on the bushings n deck support and also the front n rear bushings are squeezing tight...But the axle will swing up n down freely because the bushings are also Spacer Bushings...So when everything is very tight the axle has movement freely..


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## DForal (Jun 30, 2011)

So, is the bolt supposed to ride directly on the cross frame member? If so, it seems to me that large stresses will develop where I see the metal upset and wear on the cross frame. And shouldn't I see similar wear on the front?

Based on the drawing and your comments, it looks like the sequence of parts (front to back) is:

1. Pivot bolt head
2. Front side of cross frame
3. Front bushing
4. Axle
5. Rear bushing
6. Rear side of cross frame
7. Front linkage support bracket
8. Washer
9. Nut for pivot bolt

I agree with you that taking the deck off will make the repair much, much easier to accomplish.

I've ordered new bushings as well; to replace those I'd need to let the axle drop almost all the way out (could control the distance by slowly jacking the frame until the bushings are free). 

Originally I thought this was a missing or failed bushing problem, now that I understand the configuration and design, that is probably not the issue. The question then becomes, why did the bolt fail? Is it from my driving style? Or a defective bolt? Or a loose bolt from the factory?


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## txsteve (Dec 4, 2011)

It looks like the bolt was loose right from the factory..Then it just got loose and wobbling around till something gives..happen to be the bolt broke..but in time it wear the hole also...
But it the hole is like a hair or so bigger...No problem..just tighten it very good..


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## DForal (Jun 30, 2011)

OK, I prepared the tractor to install the new parts - hopefully they will get here by the end of the week. TxSteve, it went just like you said - thanks again for your advice and counsel. I jacked the front end up just enough to take the weight off the front wheels and I'm able to remove the broken bolt with ease.

I did put the broken bolt in the elongated hole (rear face of the cross frame) and it definitely moves up and down more than when it is in the hole on the front face. I would say it moves almost a 1/16". See the closeup picture.

Now I'm worried that if I go ahead with the repair and I get another failure because the bolt is able to move around, I'll be blamed by Sears for a bad repair. Any thoughts? Or do you think that making it good and tight and checking it periodically is sufficient? Thanks. Dave


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## txsteve (Dec 4, 2011)

1. Pivot bolt head

2. Front side of cross frame

3. Front bushing

4. Axle

5. Rear bushing

6. Rear side of cross frame

7. Front linkage support bracket

8. Washer

9. Nut for pivot bolt

I think I found why your bolt snapped...
Look at your parts for 6 n 7...
To me in your picture I don't see that the 8 washer was between 6 n 7....
So look at your 7 to see what side the washer was at before ..
The washer goes between 6 n 7...
( 6 - 8 - 7 - 9 )

If the washer was on the nut side before..That's why the bolt snapped..
Because the washer is used as a spacer between 6 n 7..
See the rolled edge lip of bottom 6..
Thats why the washer is a spacer so the 7 sits flush tight with 6 when tightening the bolt..

So where was the washer before.?


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## txsteve (Dec 4, 2011)

Don't clean your parts yet..its evidence..

So plan A OR B...

Plan A- Due to dirt that should not be at shown in your pictures between 6 8 7..If it was tight, it should be clean now..
So it was never tighten OR it was an error in the factory mess up by putting the washer on the wrong side...
Call Sears and the Tech should document the mess up...at no charge for you..
To fix it up right is welding and putting it back together right OR send you a new Frame..
Maybe sent you a new tractor ..lol..?

Plan B...get you parts,,clean off that burr by the hole,,put the washer in the right space..Tighten that bolt very good when it the tractor is on the ground..(so the weight is on the axle and bolt then tightening the nut/bolt)
It should be ok now..I don't think that 1/16 makes a deal..When its tighten the right way..
But the future..??

Me personally...Plan A and B both..
First A and at least they have the report and thinking what is the next step..and credit the parts if its factory error...

But also plan B waiting for A results...

If the results is meaning sending the tractor out to fix it just by tighten it..

I'll just stick with plan B but Plan A covers the future...


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## txsteve (Dec 4, 2011)

PS..the part diagram is for "part # information only"..

In not listed how to install what goes first..

So now you got a new code:
( 6 - 8 - 7 - 9 )
Lol..


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## DForal (Jun 30, 2011)

The washer was clearly on the nut side of the bracket (1st picture). The outline of the nut is clear on the washer and the outline of the washer is clear on the rear side of the bracket. You can also see the wear mark on the front side of the bracket caused by the burr on the frame (second picture).

So, you are saying that the drawing provided is incorrect? Why would they intentionally show the incorrect order of parts? 

I'll call them up to document and inquire about the assembly order. Everything you have said has been correct so far, so you are probably right about this as well.

Anyone that has this type of tractor, if you could report on how your bracket is assembled to the frame (washer on the rear side or on the front side of the bracket), I would appreciate it. This bracket is located just in front of the PTO pulley under the engine. Mine was assembled with the washer on the rear side of the bracket.


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## txsteve (Dec 4, 2011)

Dave...Abort the washer change I said...
I'm wrong there..
Use 6 7 8 9 ..

I just removed mine and check everything out...
I'll shoot a picture after coffee


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## txsteve (Dec 4, 2011)

Ok..the pictures are here below..

http://www.flickr.com/photos/[email protected]/

Sorry for the wrong info there about that washer...

So I guess your was loose...I notice that on mine the threads stick out of the nut like 1/4 inch...It's also a locking nut...
I use the mine like an animal working with dirt on rough terrain...
No wear sign here...


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## DForal (Jun 30, 2011)

TxSteve, thanks for taking the time to take your tractor apart and verify the condition of your hardware. As you can see from this picture, the nut was flush with the end of the bolt and yours has the threads extending through the nut by about 1/4"; there are no threads extending through this nut, so it was clearly (very) loose from the factory - photographic evidence is clear. Glad I was able to find the parts after the failure.

Here is what I'm going to do. I'll file down the burr (it was contacting the bracket) and install everything good and tight. I'll leave the old bushings in place since I have no reason to think they are defective. I'll then monitor the situation for a while to verify no motion is taking place. I think it will be OK. 

I'm really glad we were able to identify the root cause of the failure; understanding why it failed makes me feel much better about going ahead with the repair. Thanks again for all of your help.

I'll report back when I've completed the repair (hopefully the parts will get here today or tomorrow). Dave


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## wjjones (May 28, 2010)

You know I had better check mine to I have had it for 6 years, and never checked to be sure that bolt is still tight.


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## DForal (Jun 30, 2011)

Got a package from Sears in the mail. They sent me the wrong bolt (it was only 1/2" long, should be 3")  They are expediting the correct (I hope) bolt. The other package didn't arrive today, hopefully tomorrow.


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## DForal (Jun 30, 2011)

Got the second and third packages today. Messed up this part of the order as well; they did not include the nut; so I will re-use the old one. Still waiting for the bolt; hopefully Monday. Not impressed with Sears' execution - two mistakes on this one parts order. At least it is covered. Dave


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## wjjones (May 28, 2010)

Yep they did that to me but they finally got it right it takes alot of patience sometimes.


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## dangeroustoys56 (Jul 26, 2010)

I agree - a few months ago i went to the Sears in the mall to get some parts for my ancient craftsman tractor ( weirdest one ive ever seen) - besides not having any part numbers for it ( data tag was long gone) , it seems they were helpless- even when i had the parts in hand to match them up.

Ive noticed that with all newer tractor parts places - even having the original part in hand, they cant even match it up - i miss those older places where you could show em a part and they come back in a minute with a new one , even w/o looking stuff up.


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## DForal (Jun 30, 2011)

*Repair Complete*

Finally got the bolt and I completed the repair with no issues.

With the help of TxSteve, I have determined why the bolt failed. TxSteve mentioned that his tractor has the bolt extending past the nut by about 1/4", it was flush with the nut on my failed bolt (first picture). After I got the new bolt, I ran the self-locking nut down by hand and where do you think it stopped? If you said "flush with the nut" give yourself a pat on the back . Seems that during assembly, the person ran the nut on by hand and then forgot to tighten it. That support plate was rattling around loose for almost a year before the bolt broke.

As you can see in the second picture, the threads on a properly tightened bolt do indeed extend past the nut by about 1/4 inch - and it looks just like TxSteve's. Thanks again TxSteve for pointing me in the right direction. It is always nice to find the reason for a failure. Dave


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## wjjones (May 28, 2010)

That thing is right behind the muffler glad it didnt cause more damage than it did. Is it all fixed up now?


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## DForal (Jun 30, 2011)

Everything is back together and working well - thanks for asking. That deck comes on/off pretty easily and it didn't take much time to get it back together.

In fact, I really noticed a difference in the handling of the tractor. I've noticed the front end is much more responsive and "solid" when turning. 

I also sharpened the blades (they were pretty bad ) and when I mowed on Friday, it was doing a very nice job. Hope it stays this way - cross my fingers.


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## wjjones (May 28, 2010)

Yep that bracket bolt is also the axle pivot bolt I checked mine yesterday because I never thought about it until I saw your problem on here.


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## accord (Oct 22, 2012)

Had an EXACT MATCH failure on 2011 GT6000 last week. I mean EXACT match. I think the thread count on the broken bolt is even the same!


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## wjjones (May 28, 2010)

accord said:


> Had an EXACT MATCH failure on 2011 GT6000 last week. I mean EXACT match. I think the thread count on the broken bolt is even the same!




Its one of those (Out of sight, and out of mind things) I guess. I never thought to check mine to be sure it was still tight until I saw this thread. I guess just general use, and time causes it to loosen up.


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## DForal (Jun 30, 2011)

I'm 99% sure that mine was an assembly problem from the factory. The nut can be installed by hand until the deformed thread engages; when you do that, the nut is flush with the top of the bolt - exactly the condition mine was in. Since the nut is self locking, it would be very difficult for the nut to back off by itself if it was originally tightened properly. Dave


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## wjjones (May 28, 2010)

DForal said:


> I'm 99% sure that mine was an assembly problem from the factory. The nut can be installed by hand until the deformed thread engages; when you do that, the nut is flush with the top of the bolt - exactly the condition mine was in. Since the nut is self locking, it would be very difficult for the nut to back off by itself if it was originally tightened properly. Dave




Factory might have over torqued it, and stripped the threads so it was never really tight to begin with.


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