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Flail mower fail

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A year or so ago I bought a 3 point PTO driven Mott flail mower to mow my pasture with. This is an older used unit. It worked well but would slip the drive belt on heavy grass and completely lock up the drum with vines or tall weeds. I have fought this mower the entire time unless I am just mowing the light grass in the pasture. 

 

Last week I had enough fighting this thing and bought a mid mount deck mower for my tractor. This new mower is a beast and cuts like there is no tomorrow. 

 

So, today I ordered a new drive belt for the Mott and hung it up to clean it and take pictures for Craigslist. That is when it hit me......this mower turns opposite that it should. The way the gear box is made it transfers the PTO power coming into the box clockwise, looking forward, and makes the top pulley turn clockwise...........pulling on the tension pulley.....that ain't right, no wonder the belt slips. What I have determined is the mower is meant for a reverse driven PTO machine. 

IOhZySM.jpg

I thought I was going to be able to move the driving gear to the back of the gear box and change rotation on the top pulley but they did not make the shaft universal so I could not switch it over....that was a bummer to find as I had to tear the gear box 80% apart before I could see how the gear was put on. 

 

I may have a hard time selling this thing now that I know it's a reverse rotation unit....I cannot advertise it in good faith without disclosing that info. I listed it as a reverse rotation unit that works on medium grass and weeds with a standard PTO.  

 

I have figured out a way to put that tension pulley on the other side and use the original spring and pivot point, I may not get the cover back on but it should mow much better with a tight belt. I may have to try that if it does not sell as is.

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Years ago, I bought a S15 Jimmy from my uncle.  I didn't know it, but he had replaced the water pump with a v-belt driven pump.  The engine and pump had a serpentine belt and pulley system, causing the water pump to rotate backwards.  I learned all about it when the head-gasket failed.

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1 minute ago, meh77gmc said:

Years ago, I bought a S15 Jimmy from my uncle.  I didn't know it, but he had replaced the water pump with a v-belt driven pump.  The engine and pump had a serpentine belt and pulley system, causing the water pump to rotate backwards.  I learned all about it when the head-gasket failed.

This one did not give me any indication it was backwards....the blades are two sided, some mowers turn CW and some CCW......I did think it was odd that it would slip the belt so easy though, but I wrote it off as a worn belt and kept going. It wasn't until I took the guard off and put two and two together that I realized the drum turned opposite the tire rotation and when you look at the pulley system it becomes obvious that is not the way it should. 

 

I really want to see if it will work like it's supposed to but reversing the PTO isn't going to happen......my only fix is to move the tension pulley and keep it turning the same direction...it cut fine that way when the belt holds. 

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I should have known better than to speak ill of my long departed GMC.  Karma got me back for it on the way to work this morning in the form of a broken timing belt in my current truck.

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4 hours ago, meh77gmc said:

I should have known better than to speak ill of my long departed GMC.  Karma got me back for it on the way to work this morning in the form of a broken timing belt in my current truck.

Crap....that sucks!

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Buying used equipment is always an adenture.  Uness You know yuor source and can ask questions of be given a reasonabe tie to test drive, you sometimes end up with unusual surprises.

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36 minutes ago, wish2no said:

Buying used equipment is always an adenture.  Uness You know yuor source and can ask questions of be given a reasonabe tie to test drive, you sometimes end up with unusual surprises.

Pretty rare to get a backwards mower but if it can be done I'll do it  :bellylaf:

 

Looking at this thing it has been known to be a backwards mower by the previous owners and for quite some time....they have modified it to work better in reverse but they all overlooked the one big issue....the belt drive......you cannot pull power on the tension pulley. Pull needs to be direct from the driving pulley to the driven pulley.  Snooping around the shop I remembered I had a belt tension set up to run on the flat of the belt....I found that and found a piece of flat bar I needed and now all I need is motivation to swap that tension pulley from the front to the rear. It will use the same pivot point and tension spring so it can be flopped back if a reverse PTO tractor comes along that wants to mow with it. Simply taking off one pulley and adding the original back is all that will be needed. Oh, and my fix will still fit under the stock belt guard housing...win win!

 

If this all works out I am going to convert the gear box from an oil box to a grease box. I will drill and tap the lid for a zerk fitting and fill the unit with grease instead of oil. The seals leak oil and I cannot think of a faster way to fix those than packing it in grease. There are three tapered roller bearings in the box and two gears...they should run in grease just fine!

I may just keep this mower around if I get it working right. 

 

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Today I took the flail mower and worked it over changing the tension pulley from this.....

IOhZySM.jpg

 

To this......

e1PGMKw.jpg

 

Everything fits under the guard and the mower, while still operating in reverse, works like a champ. I purposefully ran it through black berry bushes and it ate everything I could feed it. Having the belt stay tight is the key :doh:    I wonder how many years this thing was operated the wrong way?......anyhow it works well now...I may just keep it around.  Best part is I can switch it back to the factory pulley by only taking off my pulley and installing the old one. 

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On 9/2/2020 at 11:24 AM, towtruck said:

Today I took the flail mower and worked it over changing the tension pulley from this.....

IOhZySM.jpg

 

To this......

e1PGMKw.jpg

 

Everything fits under the guard and the mower, while still operating in reverse, works like a champ. I purposefully ran it through black berry bushes and it ate everything I could feed it. Having the belt stay tight is the key :doh:    I wonder how many years this thing was operated the wrong way?......anyhow it works well now...I may just keep it around.  Best part is I can switch it back to the factory pulley by only taking off my pulley and installing the old one. 

 

TT : So You put another type of idler tension pulley on it  ,similar to an older automotive set up .  May I ask Why the Old pulley would tension properly ?

Did You also install a stiffer tension spring ?. It appears larger than the original spring ?.  Not to critique  ,I'm wondering how long that belt will last ,being pulled in that dramatically ?. Has to be overly stressful on the idler bearings ,especially if operating in higher RPM's .

If it's working to your satisfaction  ,that's all that really counts  :thumb:

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34 minutes ago, BushXM15 said:

 

TT : So You put another type of idler tension pulley on it  ,similar to an older automotive set up .  May I ask Why the Old pulley would tension properly ?

Did You also install a stiffer tension spring ?. It appears larger than the original spring ?.  Not to critique  ,I'm wondering how long that belt will last ,being pulled in that dramatically ?. Has to be overly stressful on the idler bearings ,especially if operating in higher RPM's .

If it's working to your satisfaction  ,that's all that really counts  :thumb:

It is an automotive pulley. The old pulley worked fine.....when the mower was operated with a reverse PTO tractor. The top pulley now turns clockwise when used with a standard PTO drive......you cannot pull power through the tension pulley......the pulley needs to be on the slack side. Now the pulley is on the correct side for a standard clockwise PTO. 

I have a new belt that is not stretched out and will give less of a bend at the tension pulley....I want to see how long the old belt lives before I replace it. 

Tension spring is the same. 

 

 

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Understood fully  and thank You for the explanation . Somewhere I missed the counter clockwise PTO rotation part but did read reverse rotation it just didn't occur to Me it was the PTO drive :facepalm: . Some days I'm quicker than others . 

 

I'm thinking about MY CJ5 hardtop , I'll be dammed if I'm forking out $3K for a glass top !. Principle knowing I paid $1,200   for the CJ , yet ended up putting that and  half again into the drive line . Also the fact I'm setting on $K's in Materials , which are doing ZERO at the moment .

So decided to get some Hat channel make a stiff back cab frame ,then  skin it 1/8" white board  adding whatever larger profile wood here and there . Then I'll smooth it all up spray release on it ,shoot it and lay it up . I Don't want to take the time and material to make a complete reversal ( female mold ) so I'll do a clean dirty male layout .

Life was so much easier and far quicker ,when I had MY shop . :tap:

 

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10 minutes ago, BushXM15 said:

Understood fully  and thank You for the explanation . Somewhere I missed the counter clockwise PTO rotation part but did read reverse rotation it just didn't occur to Me it was the PTO drive :facepalm: . Some days I'm quicker than others . 

 

I'm thinking about MY CJ5 hardtop , I'll be dammed if I'm forking out $3K for a glass top !. Principle knowing I paid $1,200   for the CJ , yet ended up putting that and  half again into the drive line . Also the fact I'm setting on $K's in Materials , which are doing ZERO at the moment .

So decided to get some Hat channel make a stiff back cab frame ,then  skin it 1/8" white board  adding whatever larger profile wood here and there . Then I'll smooth it all up spray release on it ,shoot it and lay it up . I Don't want to take the time and material to make a complete reversal ( female mold ) so I'll do a clean dirty male layout .

Life was so much easier and far quicker ,when I had MY shop . :tap:

 

Let me know if you need any numbers. I have my roof separated from the sides and hanging in the rafters...I can take measurements of drip rails and other things if you need it. 

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3 hours ago, towtruck said:

Let me know if you need any numbers. I have my roof separated from the sides and hanging in the rafters...I can take measurements of drip rails and other things if you need it. 

 

Thanks I will do once our remodeling is behind Me :thumb:

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