Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

Just Rebuilt my Kohler K341 - Balance Gears Not That Hard to Re-install


  • Please log in to reply
22 replies to this topic

#1 FilledTires OFFLINE  

FilledTires
  • Senior Member
  • Member No: 48125
  • 224 Thanks
  • 192 posts
  • Location: Maine

Posted December 22, 2014 - 03:41 PM

Hi Everyone,

 

I just wanted to report that I have successfully semi-rebuilt a Kohler K341 Engine, and wanted to let everyone know that the balance gears are not that hard to re-install without the Kohler Balance Gear Tool.

 

It took me two attempts and a total of 15 minutes. The hardest part was putting the needles back in the bearings on the first two attempts.

 

I replaced the piston, rings, gaskets, and seals, and decided to re-use the balance gears since they were in great shape.

 

Here are some pictures of the process for your enjoyment.

 

2014-11-18 16.46.06.jpg

 

2014-11-18 15.39.34.jpg

 

2014-12-20 23.22.50.jpg


  • superaben and propane1 have said thanks

#2 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,461 Thanks
  • 39,690 posts
  • Location: Collinsville, Oklahoma

Posted December 22, 2014 - 03:56 PM

It's the bearings that let go in them! Glad you got it back together! Good luck!



#3 diesel nut ONLINE  

diesel nut
  • Senior Member
  • Member No: 7572
  • 496 Thanks
  • 316 posts

Posted December 22, 2014 - 04:04 PM

Hate to say this after you got it all back together but the needles in the bearings are not supposed to be so loose that they can fall out.  All of the needle bearings I've replaced have been trapped in the housing so they would spin but they couldn't be removed without cutting it apart.       Stewart


  • Sawdust said thank you

#4 FilledTires OFFLINE  

FilledTires
  • Senior Member
  • Member No: 48125
  • 224 Thanks
  • 192 posts
  • Location: Maine

Posted December 22, 2014 - 04:27 PM

Hmmm. Mine were in tight but when trying to get the gear on the stub shaft I would knock them out trying to align in the shaft while watching the timing marks in the gear teeth. They were snug but not trapped by any kind of race.

#5 diesel nut ONLINE  

diesel nut
  • Senior Member
  • Member No: 7572
  • 496 Thanks
  • 316 posts

Posted December 22, 2014 - 04:57 PM

The outer housing acts as the race to hold them in place.  The very tip of each needle has a step on it so the lip of the housing holds it in place.  You can just about see it in the picture.  When they get worn the shaft that they ride on will start to wear away at part of the housing and it doesn't take much to let the needles fall out.      Stewart

20141222_165345.jpg


  • GTTinkerer, IamSherwood and FilledTires have said thanks

#6 lyall ONLINE  

lyall

    Tractorholic

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 2180
  • 1,747 Thanks
  • 1,398 posts
  • Location: State Center, Iowa

Posted December 22, 2014 - 05:27 PM

why did you put the balance gears back it?

On Brian Miller's web site, he going into detail about the balance gears.

http://gardentractor...com/balance.htm

 

several K serial motors I worked on did not have the balance gears in them and had no problem.


  • GTTinkerer said thank you

#7 Bolens 1000 ONLINE  

Bolens 1000

    DR. Bolens

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 7
  • 12,686 Thanks
  • 17,204 posts
  • Location: Western NY

Posted December 22, 2014 - 05:36 PM

Hate to say this after you got it all back together but the needles in the bearings are not supposed to be so loose that they can fall out.  All of the needle bearings I've replaced have been trapped in the housing so they would spin but they couldn't be removed without cutting it apart.       Stewart

 

:ditto:

 

Needle bearings are not supposed to do that!!


  • GTTinkerer said thank you

#8 FilledTires OFFLINE  

FilledTires
  • Senior Member
  • Member No: 48125
  • 224 Thanks
  • 192 posts
  • Location: Maine

Posted December 22, 2014 - 05:44 PM

:ditto:

Needle bearings are not supposed to do that!!



I must be describing incorrectly. My needle bearings didn't fall out while on the shaft. I just knocked them out while trying to get them to the shaft. They appeared to be in great shape. They looked smooth and uniform.

why did you put the balance gears back it?
On Brian Miller's web site, he going into detail about the balance gears.
http://gardentractor...com/balance.htm

several K serial motors I worked on did not have the balance gears in them and had no problem.

I have read Brian Miller's website back and forth several times as well as other forum members posts here. Based on it, I don't think they necessarily "blow up". Brian website recommends not putting them on for engines going over 4,000 rpms. He even goes on to say the balance gears help with vibration but also don't help. He contradicts himself several times. Many modern engines have balance gears in them too. I checked the gears and the bearings for wear and since they all looked good I put them back in. If they did look worn I would have left them out, due to the high cost of replacement.

Maybe I made the right call, maybe not, time will tell I guess.

Edited by FilledTires, December 22, 2014 - 06:13 PM.

  • lyall, superaben, Sawdust and 1 other said thanks

#9 Bolens 1000 ONLINE  

Bolens 1000

    DR. Bolens

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 7
  • 12,686 Thanks
  • 17,204 posts
  • Location: Western NY

Posted December 22, 2014 - 05:46 PM

Needle bearings are not supposed to fall apart at any time......



#10 FilledTires OFFLINE  

FilledTires
  • Senior Member
  • Member No: 48125
  • 224 Thanks
  • 192 posts
  • Location: Maine

Posted December 22, 2014 - 05:54 PM

Needle bearings are not supposed to fall apart at any time......

 

From the Kohler Manual:

 

"Note: Extreme care must be taken when handling the new needle bearings or when removing balance gears containing new bearings. The needles are no longer caged and will drop out. If this should occur, the bearing case should be greased and the needles resent. There are 27 individual needs in each bearing."

 

Doesn't this mean the needles can fall out or am I missing something?


  • superaben and Sawdust have said thanks

#11 superaben OFFLINE  

superaben
  • Senior Member
  • Contributor
  • Member No: 11204
  • 7,664 Thanks
  • 5,677 posts
  • Location: Shenandoah Valley, VA

Posted December 22, 2014 - 06:53 PM

From the Kohler Manual:

 

"Note: Extreme care must be taken when handling the new needle bearings or when removing balance gears containing new bearings. The needles are no longer caged and will drop out. If this should occur, the bearing case should be greased and the needles resent. There are 27 individual needs in each bearing."

 

Doesn't this mean the needles can fall out or am I missing something?

 

You're right.  Kohler does not use the standard bearings Brian is thinking about on later production balance gears.  Most of the really common K series can be either way, 50/50 split it seems to me. 

 

It is easier when they are self contained and don't blow apart... I don't know why Kohler went back to old technology, but I think it was because of the balance gears that were rupturing in service.

 

I have always reinstalled the balance gears.  The engine does run smoother compared to otherwise.  They are a pain in the tail end to install, but from my experience my customers are happier.  Kohler's short stroke design is prone to vibration, and the balance gears dampen that enough to where you can ride it most of the day without your eyeteeth starting to wiggle.

 

The main reason they blow up is too high RPM.  If you have to break 3600 RPM, better safe than sorry: take the stupid things out.

 

Ben W.


  • Bolens 1000, IamSherwood, Sawdust and 1 other said thanks

#12 FilledTires OFFLINE  

FilledTires
  • Senior Member
  • Member No: 48125
  • 224 Thanks
  • 192 posts
  • Location: Maine

Posted December 22, 2014 - 07:00 PM

Thanks Ben! I was starting to second guess myself.


  • Bolens 1000 said thank you

#13 Grumpy OFFLINE  

Grumpy

    Tractorholic

  • Senior Member
  • Member No: 440
  • 642 Thanks
  • 578 posts
  • Location: Evansville, Indiana

Posted December 22, 2014 - 07:18 PM

Take them out, and through them away



#14 NUTNDUN OFFLINE  

NUTNDUN

    Lost in Cyber Space

  • Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 3
  • 10,266 Thanks
  • 15,618 posts
  • Location: Pennsylvania

Posted December 22, 2014 - 07:48 PM

I took the balance gears out of the 16hp Kohler I have. I didn't want to have to worry about them and while I can't tell a huge difference with them not in there it does shake a bit at certain rpms. Every Kohler I have had though has had the same notorious shake at certain rpms. It is your engine and if you want them in there you have every right to. If you don't plan on revving the crap out of the motor and the bearings were in good shape along with the shafts then you shouldn't have much of an issue. Just realize that it is another failure point but one that you may never have an issue with.


  • GTTinkerer, IamSherwood, LilysDad and 3 others have said thanks

#15 superaben OFFLINE  

superaben
  • Senior Member
  • Contributor
  • Member No: 11204
  • 7,664 Thanks
  • 5,677 posts
  • Location: Shenandoah Valley, VA

Posted December 22, 2014 - 08:27 PM

George, you are right.  Kohlers are prone to certain RPM vibrations, especially low idle.  I had one K321 (probably my favorite Kohler, such a powerful guy with great versatility) that I had adjusted to the point to where it would sit there and literally rock back and forth on the floor as it staggered along at idle.  That one was untouched with factory installed balance gears too.  :rolling:

 

I just know from rebuilding countless Kohlers that the only balance gears that blow up are those that are installed incorrectly (easy to do... ask me how I know sometime when its not embarrassing :D ) end up with bad bearings, or are used at high non-governed RPM.  Cast iron can't take that much centrifugal force without blowing to smithereens.

 

Kohler installed them for a reason.  I forget where I read the scientific breakdown of how they work, but from my experience and from those who I have talked to in the performance world, they actually do more than balance the vibration.  My belief from doing some history research is that they are designed to increase power by reducing friction and the physics of having to overcome the "throwing" force of a piston and rod.   I know Kohler claimed that they also affected fuel economy, not like that really matters to us. 

 

However, the opposing side will say that if the ol' balance gears are so great, why didn't every other small engine manufacturer join in?  I simply don't know.  I know Kohler guys have struggled installing them from day one, and I know early balance gear failure gave them the reputation as the Achilles heel of the K series. 

 

Personally, I like them.  When I do a rebuild, they get rebuild and they go in, timed right. 

 

Here's something else to chew on.  This is the most scientific thing I know to throw in this discussion.

 

Kohler engines with balance gears have smaller crankshaft counter throws.  A counter throw is every other manufacturer's way of balancing compression and the explosions of combustion.  When you take out the balance gears, you have an engine out of balance even more than what you have on any other engine.  That is rough on the main bearings, hard on the cylinder, and will wear out the engine faster.  What I am saying is that a Kohler crankshaft is not setup the same as (say) a Briggs.  Balancing via two gears instead of a real counter throw was a Kohler innovation, maybe wrong but innovative nonetheless.  Once I learned that, I started doggedly believing that the Kohlers need those two little doohickeys to last well. 

 

Ben W.


  • Sawdust and FilledTires have said thanks




Top