K301 Connecting Rod

[mattoney]

Hey guys, maybe you can help explain something to me.

I've got a K301AS out of a Cub Cadet 122. S/N C003586, Spec 4759B.

I had to turn the crank down .010 and had to get a new connecting rod. My research on partstree.com and Kohler Engines says I need P/N 47 067 10-S. I ordered a new one from NAPA.

When it came, I installed it and decided to give it a crank by hand to make sure all was well and found it was not. The I-beam of the connecting rod is much wider by the crankshaft, and beats against the cylinder wall.

I have since ordered three more connecting rods, each time from Kohler. Twice from NAPA, once from Carquest, and once from John Deere. (The nearest CC dealer is a way's away.) Each time, the box from Kohler is labeled "47 067 10-S" and the part inside is "47 059 07".

I know y'all will want pictures, but the tractor is at my parents' house at home. Hopefully I can get some pictures tomorrow when I'm there.

Anybody else run across this problem? What'd you do? I'm almost afraid to order anything from anyone now, in fear of getting this larger rod again and not being able to return it.

Thanks for any help you can provide!

[R Bedell]

According to the Kohler Web Site, the 47 67 10-S is the correct connecting rod for your motor (.010) undersized.

I suspect, that the 47 059 07 is just the upper part of the connecting rod, while the 47 067 10-S is the kit, rod and cap.

[mattoney]

Originally Posted by R Bedell

According to the Kohler Web Site, the 47 67 10-S is the correct connecting rod for your motor (.010) undersized.

I suspect, that the 47 059 07 is just the upper part of the connecting rod, while the 47 067 10-S is the kit, rod and cap.

All the 47 059 07's I've seen so far have come with rod with threaded studs, cap, and nuts. I'm a little confused by your comment. Can you explain?

It looks to me like a complete rod that should go on a bigger engine. I've been doing some research to find where this rod is used, and I'm seeing K301 alot, but I am also coming back with a few hits on K341's.

[Matt G.]

The number cast into the rod is a casting number and has nothing to do with the final part number. You are correct, you cannot buy just the top part of the rod with no cap and fasteners.

This is a really odd problem, because IIRC, the K241 is a shorter stroke, and the K301-K361 are all the same stroke and therefore have the same length rod. Pictures would be really helpful.

Are all three of those rods physically identical?

[Merk]

Is the motor a K301 or a K241?

What is the cylinder bore measurement?

[R Bedell]

According to the Kohler Website, the 47 067 10-S is used on 891 applications for the K301, K321, M-12, & M-14 motors. In other words, most all 12 & 14HP K and M series Kohler Motors.

[samiam44]

I don't understand the parts difference and exactly where it is hitting.

Maybe some pictures of new vs old rod, piston, crank and the installation so we can see the problem.

I would guess the new rod to be better/beefier than the old ones.

Michael

[mattoney]

Sorry guys, too busy at work today to get any measurements. I'm hoping to take some measurements and get some pictures of the two rods side by side. I also tried to get some pictures from inside the block but I can't get my camera maneuvered around where I need to get a good view. I'll keep at it though.

As for Kohler genuine or not...when I rebuilt this engine a few years ago, I got a "kit" from Stens. It had the correct std sized rod that ended up coming loose. The rods I am finding are coming in boxes marked "Kohler" and "Genuine Parts" with the blue and white K design I've seen for years. Unless someone is switching the parts, I believe them to be genuine.

As for whether its a closet K241, when I measured the bore on the block, it measured the specs matching a worn K301. Due to the amount of deep scratches I saw in the sidewall, I had it bored 10 over. If something wasn't right here, I would have caught it. I do not remember measuring the stroke at that time. I was more concerned about the walls.

Sorry I don't have pictures to show you yet. Hopefully tomorrow. Hope this information helps out.

[samiam44]

Matt,

This is the text from a Kohler factory piston kit on the internet.

"There are 2 basic designs, the Old Style piston and the New Style (Mahle) piston. If you have the Old Style piston and you are Not replacing the rod you have to stay with the Old Style piston design.
If you want to upgrade to the better New Style (Mahle) piston you can but you have to also replace the rod with the New Style rod.
The Mahle style piston skirt profile was modified to provide a better fit within the cylinder bore. The ring channels were redesigned and the wrist pin was strengthened. A different connecting rod is required because of the extensive design changes.
Beware of shops selling the aftermarket "rebuild kits" more then likely these are imports. These parts in many cases will not inter-change with genuine Kohler parts, example aftermarket rings will not fit in genuine Kohler pistons. They are also selling the old style piston design, further they are also claiming "It's what the rebuilders use". In my 30 plus years in the power equipment industry I have never heard of the term "rebuilders" in the small engine business unless they may be referring to backyard mechanics that are using aftermarket internal engine parts. You may be saving in price but not Quality."


I think this is the problem you are having...

[mattoney]

Alright guys, big update. After I woke up from Thanksgiving (aka "food coma"), I got pretty busy with work, but I did have some time to do some detective work.

Samiam44, I found the same article you quoted from, on http://www.kohler-engine-parts.opeen...ts/piston-kits. According to the piston design, the kit I have (which I'm pretty sure was manufactured by Stens) includes the old style piston. I have had Kohler places ask me if I'm using the old style piston, and this is the connecting rod they've come back with. But the connecting rod and piston seem to work well together. It's the piston vs the block that is the problem.

So I took some pictures, and I took some measurements for y'all to see. A picture is worth a thousand words, and I tend to be rather wordy, so maybe this will shut me up!

First picture is of the difference in size. I put the old rod on the left, new rod on the right, and measured the width of the rod in the area where it was hitting using calipers available at work. I measured the new rod at 0.200" wider than the old in this area.

https://lh5.googleusercontent.com/-P...20modified.JPG

The second picture is a zoomed in view of where the rod was hitting the bottom of the cylinder wall. There was a bit of flashing left from when it was cast, and you can see two lines; one where it hit the cylinder wall when I turned the engine it's proper rotation, and the other where I turned it backwards to see if it would hit that way too.

https://lh3.googleusercontent.com/-5...0/100_1590.JPG

At the suggestion of the last Kohler dealership I talked to, they recommended polishing this area down to remove that excess material, and see if it will fit then. I have polished it down very carefully, making sure not to take off much material, or let the rod get too hot in the process. Here's the finished product.

https://lh3.googleusercontent.com/-M...0/100_1591.JPG

I'm pretty excited to put this thing back in and see if I have enough clearance, but it'll be a week or two before I get the chance to do so. It doesn't seem like it'll take much to clearance the rod, so I'm hoping what little I did will make the engine and its owner happy.

I apologize if I am not posting my pictures correctly. I know some forums get pretty upset about this. If I am doing it incorrectly, please let me know and I'll e happy to fix. I haven't yet found the rules for posting links to pictures hosted elsewhere.

Thanks for all your help, and I'll keep you updated.