Spun or worn rod bearing test
- Thread starter Fishfarmer
- Start date
Thanks! Yep… I see the overhaul kits include liners…. Live and learn….(Learn not to believe everything the Kubota parts guy says.)
Now that I know it’s a sleeved engine… let me tell you about one that taught me a lesson about “knocking” sounds: I was given a Ford that ran poorly and discovered one cylinder which was very low on compression and had a Hell of a KNOCK…. (wonder if this might apply to your situation)…
I finally decided to tear it down and repair it before it threw a rod… so, I pulled the front axle from under it and blocked the frame up, dropped the sump …and found shards of steel laying in the bottom of the sump. Pulled the head and found cylinder number 1 had a shattered sleeve, most of which was in the sump! Yet that engine was running and producing enough power to run a 6-foot shredder…. but with a heck of a “knock”.
I ordered the overhaul kit and replaced all sleeves, pistons/rings, and conn-rod bearings….and didn’t touch the mains or the valves….and put it back together. Ran that tractor for 15 years mowing with a 6’ Rhino shredder as a “pull-behind” mower and definitely got my moneys’ worth!
Wouldn’t it be grand if you only have a cracked sleeve…err…I mean “liner”…and no other damage…??
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The M4500 engine is a sleeved engine. The new sleeves come semi-finished and do have to be honed. to size. You can bore the original sleeves one time for an oversized piston. Can remove the oil pan after removing the front end. You can remove the Pistons after removing the head and pan. You cannot inspect the main bearings as this engine must have the crankshaft remove out the back of the block like many of Kubota engines. This is not a hard engine to work on. This was a popular tractor used in the vineyards in my area. When they run correct they sound like a sowing machine. Good luck with your project.
That seems great news, if I understand correctly, the new sleeves be honed to size with an ordinary hone on low speed drill e.g. Sunnen hone or Flex hone? No need for a machine shop to bore them first? I was under the impression that they needed to be bored first, but it would be great if they don't need to be.
Thank you I do need luck. My compression is very low on one cylinder 200psi, all others are 380psi. Assuming this piston and sleeve are damaged, I was hoping to remove the pan and the head with engine attached to the tractor, replace the piston and sleeve and hone it on the tractor. From my research I see that semi-finished sleeves need boring. Now I think I will need to remove engine from the tractor and get the sleeve bored at a machine shop. If you have any suggestions?
....you don't want to hone without removing the crankshaft
where's the material that you're removing go? On/in the crankshaft (and everywhere else).
do you wanna do it right. Or do it twiced?
where's the material that you're removing go? On/in the crankshaft (and everywhere else).
do you wanna do it right. Or do it twiced?
I’ve successfully honed cylinders with the crank in-position by shielding the crank with a wrapping of plastic food-wrap and/or rag. Wash it all out thoroughly afterwards using stoddard (safety) solvent and put it all back together. (That’s also how I did the Ford I mentioned previously and ran it hard for 15 more years without engine troubles.)