Om, How are things ? I dont know how to determine a runaway or overspeed ,
I dont understand how it could be accomplished with this unit ! When I first aquired this engine , You could turn it over about 280 degrees , I took the injectors out and filled the cylinders with marvel myst oil , thinking I had a rust ridge . to no avail , so in between jobs last summer , I pulled the heads , Found mud and water evidence , in the exhaust manifold and head ports , So I pulled the heads , cleaned out marvel & dirt residue , Stone honed sleeves to top of pistons and filled with kroil . After acouple weeks of tapping the pistons with dead blow& block of wood and rocking flywheel with bars ,came to the conclusion time to pull the engine out of the machine , maybe now that I have the sleeves & pitons out, by some chance pressing # 4 piston out of the sleeve may turn up some indicaton as to why this engine so abruptly stopped!!
Chas

Hi Chas,
Water & mud?? Seems like maybe this one got submerged somewhere along the line. Quarry operation?? Gives credence to sabotage or vandalism!!.
Yes, pay particular attention to #4 (with the bent rod, right?)

You wouldn't think you could overspeed one of these huh. Rest assured if it can be done, some clown will find a way:(
This particular one was victim to a "monkey" that decided to run a vent line from a normally closed hydraulic surge/holding tank into the engine air intake pipe. No problem.........until the hydraulics were operated (makes great fuel). It was over in about a minute.
The forensics were an assortment of thrown rods and collapsed pistons due to valve float but there were two holes with just bent rods and sheared ring lands. All we could figure was the high revs allowed more than the usual piston travel and met with the cylinder ridge. Although the cooling system was breached no water or liquid fuel was found in these same cylinders.

Hey OM & SJ , And everyone else , I finally got the last two cylinders cleared, there seems to be some light rust around the rear main bearing , with all the pistons and sleeves out the crank seems to turn quite free !! The oil pump seems to be a little stiff , I am going to dissassemble and see if the gears are rusted ,
The crank doesnt appear to be too bad , Like I said once befor maybe a little
crokus ?? I am going to drop the rear main cap and see if there is rust on the journal ?? may be I can get away with tapping the bearing shells out and just cleaning the journals with crokus ?? What do you guys Think?? The cam appears to be perfect , I drained the oil From the pony , Flushed and refilled
with 30 wt. Throttal butterfly was stuck WO , Freed that up , next chance I get I am going to try to run the pony for a minute or two . !!!
Regards to all ,
Charles Poole
PS, May have located A 1956 , D 6 , 9 U , that used to belong to my dad !!!!
First pony I ever started , First dozer I ever Ran !! Hope I can aquire It , Chas,

Yes there is no reason why you can,t polish up the journal but clean it good after your done. Also you,ll need to drive new rope cord in each side of the cap where that groove is on each side of the cap. You do it after you torque the cap nuts.Cat should have it yet I,m sure.The spool of cord is 2B2414 at Cat.I always lapped it over from one side to the other as I installed it so don,t just drive it in straight.You can take a welding rod to make a driver till you get it out where a small punch will drive it in tighter.

Hi Charles,
Progress seems good:D Clean it up and measure it up.....no show stopper yet.

Interesting find on the D6.........hope you get it.
The 9U is my favorite tractor.