Jump to content

Garden Tractors and Parts on eBay



Photo
- - - - -

Kohler KT17 / Ariens GT17 Crankshaft / Front PTO Damage


  • Please log in to reply
17 replies to this topic

#1 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 17, 2017 - 10:52 PM

Evening All,

During my GT17 teardown I found what appears to be damage to the keyway on the crankshaft stub for the front PTO. It appears to approximately correspond to the length of the PTO key.

I was hoping you all could give me your thoughts on if this was normal or not and what a fix might be if not.

I suspect the proper fix would be to weld and re-machine, though the thought of possible distortion of the crank gives me pause. Would filling the gap with JB weld and sanding smooth be an option? d8f353874f3cfcb706a95b9c0be8228c.jpg4d8fdf00a6494dcb4e5c0985d99f147c.jpgc1e0d511e54f24f34d592836bf9f4e71.jpg

Sent from my Pixel using Tapatalk

Edited by distephano, November 18, 2017 - 01:50 AM.

  • boyscout862 said thank you

#2 Eric OFFLINE  

Eric
  • Senior Member
  • Member No: 41778
  • 1,317 Thanks
  • 811 posts
  • Location: Wisconsin

Posted November 18, 2017 - 01:46 AM

I would think jb weld would be sufficient if you built it up and sanded it back to factory specs. If it has set screws to hold it in place it would be even better.

#3 1oldbuzz OFFLINE  

1oldbuzz
  • Senior Member
  • Member No: 61298
  • 486 Thanks
  • 405 posts
  • Location: Manitowoc WI

Posted November 18, 2017 - 02:22 AM

I would use a new key that is the full length of the way


  • boyscout862 said thank you

#4 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 18, 2017 - 02:32 AM

I would use a new key that is the full length of the way

That was my first thought as well, but the outboard portion of the pto needs to spin independent of the crankshaft yet. I guess I could get a full length key and machine the thickness down on the portion that extends beyond the keyed portion of the pto clutch.

Sent from my Pixel using Tapatalk

#5 1oldbuzz OFFLINE  

1oldbuzz
  • Senior Member
  • Member No: 61298
  • 486 Thanks
  • 405 posts
  • Location: Manitowoc WI

Posted November 18, 2017 - 03:26 AM

Ok

I would not go the JB weld route

you could try a dremel with a cutting disc

and grind it for a half round key

or attempt to grind out a new key on opposite side of crank

check with local machine shops they

may?? be able to do the work

without removing the crank

find new/used crank

 

I also think you would be ok with welding

find a piece of brass stock to fit the key

fill in with weld and file

I don't think machining  would be needed

The only thing I would worry about

would be the heat ruining the crank seal


  • boyscout862 said thank you

#6 MiCarl OFFLINE  

MiCarl
  • Senior Member
  • Member No: 75926
  • 1,817 Thanks
  • 980 posts
  • Location: Livonia, MI

Posted November 18, 2017 - 07:39 AM

It looks like that seal can be replaced from outside so I wouldn't worry about damaging the seal (assuming you can source a new one).  I'd pull that seal out before using any heat just to keep it from leaving melted/burned bits on the crank so the new seal leaks or wears fast.

 

I think a good welder could fill that without putting too much heat into the bearing.  The tricky part will be getting the slot cleaned up.

 

Of course if you're disassembling the engine a crankshaft shop can repair it.  My neighbor that does crankshafts regularly makes those kinds of repairs.


  • boyscout862 said thank you

#7 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 18, 2017 - 08:00 AM

At this time, the plan wasn't to open the engine. It has good compression and ran fine. It was mostly removed to clean, remove massive mouse nests packed into the shrouds, and replace hoses and ignition components as all of the wires and hoses were extremely brittle and falling apart.

At this point, I'm tempted to go the full length key route. I have access to a machine shop, so getting the outboard end of the key machined to thickness should be simple.

I'll have to go look at the whole assembly again to make sure that won't be an issue. If I take the key right to the end of the shaft, the washer and bolt should keep it from moving axially and causing anything not intended to be keyed from riding up on it.

Sent from my Pixel using Tapatalk

Edited by distephano, November 18, 2017 - 08:42 AM.

  • KennyP and boyscout862 have said thanks

#8 29 Chev OFFLINE  

29 Chev

    A Little Off Plumb

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 63590
  • 7,446 Thanks
  • 2,435 posts
  • Location: Ontario Canada

Posted November 18, 2017 - 09:22 AM

You may want to put a dial gauge on the crankshaft near the outer end and check to make sure it is running true and not bent - just a suggestion.


  • boyscout862 said thank you

#9 boyscout862 ONLINE  

boyscout862
  • Senior Member
  • Contributor
  • Member No: 8923
  • 12,140 Thanks
  • 8,870 posts
  • Location: N.E. Connecticut

Posted November 18, 2017 - 09:35 AM

What did the key look like? I've seen that kind of thing when someone used a steel key where a soft key was supposed to be used. Good luck, Rick



#10 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 18, 2017 - 09:45 AM

I'm actually questioning how things were put together. I was going to leave this part out, as it was a very embarrassing and VERY expensive mistake, but I actually destroyed the keyed portion of the PTO removing it. It was really seized to the crank. I had to purchase a new front PTO assembly. Ouch.

I'm now wondering if the key was installed rotated about its axis 90 degrees so the region intended to fit the shoulder of the crankshaft actually allowed it to wiggle. If it cocked in the keyway, that would explain why I couldn't get the thing off.

More photos below. c41f78462aaabb274a28b00c7329cdaa.jpg3df09dbfa7a8cd186cd153e7935a20e7.jpg36546a6aa454bf60b53eb7288b51608e.jpg

Sent from my Pixel using Tapatalk

#11 dodge trucker OFFLINE  

dodge trucker
  • Senior Member
  • Member No: 19314
  • 2,120 Thanks
  • 2,831 posts
  • Location: kankakee

Posted November 18, 2017 - 10:05 AM

put a full length key in (at least longer than the damaged section of crank) and you will be fine. look at the outer shell that actually turns, there is a bearing that goes onto the inner hub that turns with the crank. There has to be, or there would be no reason for an electric clutch at that point because if the key engaged the outer hub it would lock inner and outer portions together so it would be locked to the crank and spin any time the crank rotated.

look in that pic and you can see how deep the inner hub sat on the crank, I would put a key in there at least as long as that. The crank has "rings" on it sort of like the ones that tell how old a tree is, for lack of a better explanation coming to mind. seems shinier and goes to a darker tint where the inner hub stops. That right there would give you nearly double length on the key which would be a stronger transition.


Edited by dodge trucker, November 18, 2017 - 10:08 AM.


#12 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 18, 2017 - 10:19 AM

put a full length key in (at least longer than the damaged section of crank) and you will be fine. look at the outer shell that actually turns, there is a bearing that goes onto the inner hub that turns with the crank. There has to be, or there would be no reason for an electric clutch at that point because if the key engaged the outer hub it would lock inner and outer portions together so it would be locked to the crank and spin any time the crank rotated.
look in that pic and you can see how deep the inner hub sat on the crank, I would put a key in there at least as long as that. The crank has "rings" on it sort of like the ones that tell how old a tree is, for lack of a better explanation coming to mind. seems shinier and goes to a darker tint where the inner hub stops. That right there would give you nearly double length on the key which would be a stronger transition.

Dodge,

You make a good point. I over simplified my thinking of the outboard portion of the pto on the crank. It does ride on a bearing, though not keyed. So as long as I can get that portion over the crank, things should be fine. I'll pick up keystock today and get to work making a full length key!

Sent from my Pixel using Tapatalk

#13 EricFromPa OFFLINE  

EricFromPa

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 2135
  • 3,382 Thanks
  • 3,014 posts
  • Location: Bedford County Pa.

Posted November 18, 2017 - 12:14 PM

Ok

I would not go the JB weld route

you could try a dremel with a cutting disc

and grind it for a half round key

or attempt to grind out a new key on opposite side of crank

check with local machine shops they

may?? be able to do the work

without removing the crank

find new/used crank

 

I also think you would be ok with welding

find a piece of brass stock to fit the key

fill in with weld and file

I don't think machining  would be needed

The only thing I would worry about

would be the heat ruining the crank seal

 

I was going to suggest welding with the Key installed. But with a Sacrificial Brass key as @1oldbuzz suggested, you could knock it back out and clean it up with a couple good files or dremmel and it should look as good as new.

 

Here is 1/4" Brass key stock but you might a chunk locally at a hardware store.

https://www.ebay.com...D0AAOSwa~BYdvNy

 

I would Replace the seal anyway. It looks like it's been seeping. Crank seals are easy to replace but they are $5-$20 depending where you look so it's not going to cost much. 

 

 

I'm not sure what the sheer strength + Heat + Oil resistant JB weld is. Every time you engage the PTO it hammers on the Key pretty hard. I would think that if you hit something with the deck it's going to do bad stuff.  I just don't think JB weld is going to hold.



#14 distephano OFFLINE  

distephano
  • Member
  • Member No: 88261
  • 9 Thanks
  • 12 posts

Posted November 18, 2017 - 12:58 PM

I would Replace the seal anyway. It looks like it's been seeping. Crank seals are easy to replace but they are $5-$20 depending where you look so it's not going to cost much.


I'm not sure what the sheer strength + Heat + Oil resistant JB weld is. Every time you engage the PTO it hammers on the Key pretty hard. I would think that if you hit something with the deck it's going to do bad stuff. I just don't think JB weld is going to hold.

Agreed. I'd like to have it welded, but the snow is already flying here in Wisconsin, so I don't have the luxury of time. I think creating a new full length key is going to be my most timely and economical option.


I'm going to replace the crank seals. I actually have a full seal set. I needed the seal for the oil block off plate because I'm going to add a filter. Going rate was nearly 20 bucks! By the time I counted up the handful of others I needed after disassembly, it was cheaper to spend 50 some odd dollars on a full set.

Sent from my Pixel using Tapatalk

Edited by distephano, November 18, 2017 - 12:58 PM.


#15 MiCarl OFFLINE  

MiCarl
  • Senior Member
  • Member No: 75926
  • 1,817 Thanks
  • 980 posts
  • Location: Livonia, MI

Posted November 18, 2017 - 02:32 PM

I can't imagine the key did that to the shaft without the PTO being wrecked anyhow.  All wadded in like it must have been it wasn't going to cooperate.

 

With the key on the shaft it looks like you could slide the new seal over it.  Once I was sure I had a key that worked I'd be tempted to weld in place by back filling the hole.






Top