D180 Kohler Twin Crank Replacement

[BigRedD180 1]

Went out to fire up the horse to do some snow plowing and it cranked over a few times then made a clank noise then would not turn over. I separated the engine and tranny and this is what I found:

The keyway slot was blew out of the crank and it took out the stator and flywheel. I ordered a Flywheel and stator from JDog (thank you) and found a crank and cover plate locally.

My question to you guys is:

Has anyone sucessfully replaced a crank with existing rods? Or any links to instructions would be greatly appreciated.

I have been talking to a guy I work with and he recommended using a plastigage to determine if it will work with the rods but other than that he was not sure on the Kohler 18 horse rods and crank. I did download the Engine Manual from Kohler and plan to order a overhaul gasket kit but want to see if anyone has attempted this daunting task and was successful before I spend too much time and money.

Thanks in advance,

Mike

[TT-(Moderator) 1,127]

Wow! Whoever worked on that before must not have had their pipe wrench set for the proper torque on the flywheel nut..

If you're asking if you can swap cranks without disturbing the rods, it should be "do-able".

If you want to know if the replacement crank will work with the existing rods, you'll need a micrometer to check rod journal size on both cranks. If they're the same ( neither one was ground undersize) you should be good to go.

[d180man 5]

Hi i would check the rod and crank if i was doing it ! good luck on getting it up and run!!! :banghead:

[BigRedD180 1]

Ahhh, you noticed. Silly me for getting the correct tool when I could have used the BFPW. Thanks for the input, now the fun part of dis assembly

I'll keep this thread updated on the progress I am making.

This is gonna be a fun project and needs to be done soon cuz the snow ain't stoppin' and I AIN'T SHOVELIN'.

[JimD 3,345]

BFPW. hope you get it going soon!

[rickv1957 70]

10-4 on the BFPW,Rick

[big mike 13]

I know this won't be the answer you want to hear(or maybe it will )

Your going to have the case split so you will want to replace the governor(yes,you really do)as long as your in there you might as well have the valves ground,if you do the they may as well bore the cylinders while they have the jugs.If your in this far I would strongly suggest turning the crank and putting in new rods.Once this is done you can do regular maintenance and sleep sound for the next 20 yrs and not have to wonder when a rod is gonna let go and take out the crank,cam,case,cylinder or whatever else gets in the way.

Plastigauge will only tell you the clearance it won't tell you out of round or taper on the crank journal.The other important thing to remember about rods is they may check ok but be right on the verge of breaking and you will have no way to know.

Long way to the answer,yes it can be done but to me does not make long term sense.

[TT-(Moderator) 1,127]

I know this won't be the answer you want to hear

Replace the governor? Split the cases?

Hold on there, Big Mike.

It's a K-482. You know - the external governor, BIG iron block industrial-type Kohler 18hp twin? With proper PM, I've seen them accumulate well over 3000 problem-free hours (on skidloaders), so this one could still be as "tight" as the day it was built.

Nothing was mentioned about oil consumption or strange noises, so unless this engine was in bad shape before the flywheel came loose and split, I wouldn't fix anything more than I had to -- but that decision is entirely up to the owner and the current contents of his wallet. :banghead:

[BigRedD180 1]

Big Mike, I would love to do a total rebuild on this but I am already $250 into the project and I think the old lady would blow a gasket if I spent any more. I really appreciate the input though.

The engine was running fine until this incident, no smoke and turn key start up every time, so I am hoping that just gasket kit and crank swap gets it plowing again.

Just waiting on parts to get started, then I will post some pics of the progress.

[big mike 13]

The Kohler 18 hp part said Magnum to me.....did not know they used the K series twins.Sorry for the confusion.

[BigRedD180 1]

It is always interesting what you find when you tear down a 36 year old tractor, I had to remove the heads in order to get the crank out because the pistons would not go far enough into the cylinder. I found that someone must have lost something down one of the cylinders either during a repair or rebuild. I wonder what it could be.......

Judging by the imprints in the HEAD, I would conclude a screw was lost down the carb or Joe PipeWrench forgot something in the cylinder when he was putting it back together

The other thing that bothers me, is that I found this in the other cylinder. I remind you that the engine ran great but I don't know how......

I may have to take Big Mike's suggestion and get some over sized pistons and get it bored. BUT if the engine ran fine, I may just slap it back together and anticipate a rebuild in the spring.

I'll tell ya what, I glad I just bought a parts washer basin cuz this mother of a horse is DIRTY. Shes my Dirty lil Horse

Mike

[Duff 206]

I'm no engine man (to put it mildly), but with those ding marks in the head I'm surprised the top of the piston wasn't all tore up....unless the pieces blew out through the exhaust somehow before things really got to flying around.....

Duff :thumbs:

[rickv1957 70]

One thing for sure,them old kohlers are a tough,long life engine!,Rick

[BigRedD180 1]

Ok, I got the engine back together, put the flywheel on and was ready to bolt the flywheel to spline adapter for the pump and found that the screw holes are not the same as the original

Heres the broken one:

Here is the new/used one:

As you can see there are 4 holes in the broken fly but only 2 in the new/used Unfortunately I notice this WHEN I AM ABOUT TO BE DONE

Is there a different size adapter that I can buy? I really dont want to have this machined or make an attempt at centering and drilling on cast.

Thanks

Mike

[Kelly 1,028]

If it was mine I would pull it and have a machine shop drill and tap it, and be done with it, I know more time and money but will be done right, might not be that much money to have done??

[rickv1957 70]

I would do the same as Kelly suggested!,Rick

[chris11 184]

I could drill and tap it for you if you want to send it to me. just pay for shipping

[BigRedD180 1]

Chris,

Sent you a PM

Thanks

[BigRedD180 1]

ITS ALIVE!!!!!!!! It has been a looooooooonnnnnggg process but nothing compares to when you hear that twin pipe poppa fires up again. And just in the nick of time, I have been fortunate that it has been a mild winter in Western Michigan but it looks like I be back in the saddle again tonite with the storm that is rolling thru right now.

I'll post some action pics.

Thanks for everyone's help. B)

[Save Old Iron 1,563]

I think the old lady would blow a gasket if I spent any more.

I have replaced one or two of these "gaskets" and they ain't cheap either !! B)

[rickv1957 70]

Thats great you got your D 180 going! Rick

[sorekiwi 761]

Glad to see you got her running!

What did you end up doing for the scored bore and dinged up piston? And did you just drill and tap the other two holes in the flywheel?

[BigRedD180 1]

I honed out the cylinder and on my first compression test it had 110 lbs, better than the other side that looked ok. The piston was not dinged up, it looked like a screw got into the cylinder and made the impressions on the head and the person that had the tractor before me had to replace the piston because it was stamped STD, which I believe is aftermarket marking.

The Flywheel, I work with a guy that used to be a machinist and I took it over to his house one night with the original flywheel, lined up the holes and then CAREFULLY drilled and tapped the holes. That went surprisingly well, I took machining classes but that knowledge is only as good as the tools you have available to you and I need a bigger garage. Some day I'll build one out back, going to need a place to hide out considering I have my 3rd girl on the way.

She's running pretty good, I plowed tonite but I think that I have to do some adjusting on the governor because under load it does not get the R's up to compensate for the load but she still got the job done.

I am curious if I have the right governor on the engine because when I bought the tractor, it came with spare parts including this governor. It is different, in that the 2 linkage arms are shorter than the original but I figured that I should replace the original because one of the slots for the mounting bolts was broken. I am going to have to play around with it this weekend.

Mike

[bitten 133]

Hey Mike glad you got it running in time for the snow. Are you going to do a rebuild on it still?

[Sparky-(Admin) 19,546]

Glad to hear this story has a happy ending .

Mike.....