Piston Stuck

levsmith

Member
I finally got out in the garage today to start putting my project 3400 back together. The plan was to get the head put on today and check compression. Once I got out there I realized one of the pistons was not moving when trying to turn the radiator fan. I sprayed penetrating oil around the edges of the piston and let it sit a few hours. After some tapping with a wood block, I realized the piston itself is wiggling, but it still is not moving up and down. Does this sound like the stuck rings to you or does it sound like maybe rod bearings or something else.

As a background, I received this tractor with the head already removed and rebuilt. The previous owner had a heart attack and didn't have the energy to finish it. All of the oil was drained from the oil pan and it has been sitting with the head off for a few years (stored inside the garage). The pistons were free when I bought it and were free probably 6 months ago when I tried it, now the one is stuck.

This is my first time doing anything inside an engine, so I am a little outside my comfort zone, but trying to learn.

Thanks for any help.
 

Sorry, I didn't specify that. Two of the pistons move up and down maybe 1/16"-1/8" while I am turning the fan back and forth, but you can tell the third piston isn't moving at all.
 

Hey Larry
Unfortunately I do not know what the damper nut is, I am not real familiar with engine terminology other than the major components. Good news though, I got a wrench on the nut for the big pulley on the front of the motor (maybe atached to the crankshaft?). After wiggling back and forth on it, the piston started moving and eventually freed up. It is all moving as normal now! Thank you for the idea, it got me going in the right direction at least
 

Since it has been sitting for two years since assembly it would be a good idea to check for lube on one of the bearings. If it has assembly grease you should be good if it was put together with just oil it would be good to remove the caps on the mains and the rods and lube them. Even if you put it only on the caps it would be way better than nothing. In addition you probably already know that you want to pressurize the oil system before starting it. Do you know if he plasti-gauged the bearings?
 
(quoted from post at 17:27:04 01/01/18)
Since it has been sitting for two years since assembly it would be a good idea to check for lube on one of the bearings. If it has assembly grease you should be good if it was put together with just oil it would be good to remove the caps on the mains and the rods and lube them. Even if you put it only on the caps it would be way better than nothing. In addition you probably already know that you want to pressurize the oil system before starting it. Do you know if he plasti-gauged the bearings?

Showcrop,
The engine itself was never disassembled. The only thing that was done was the head machining and rebuild. I do not know what plasti-gauging the bearings is but I am assuming it is not something you do to the head. If it is, I know the head was machined and rebuilt by a reputable local machine shop, so everything on it was probably done right. I did not know about pressurizing the oil system, but I do understand the importance of having oil on the first start. I will check into the process to pressurize the oil system. Thanks
 
(quoted from post at 18:44:26 01/01/18)
Hey Larry
Unfortunately I do not know what the damper nut is, I am not real familiar with engine terminology other than the major components. Good news though, I got a wrench on the nut for the big pulley on the front of the motor (maybe atached to the crankshaft?). After wiggling back and forth on it, the piston started moving and eventually freed up. It is all moving as normal now! Thank you for the idea, it got me going in the right direction at least

Nut for the big pulley = damper nut. The "big pulley" has a viscous or rubber ring between its inner hub and its outer body. This serves to "dampen" vibrations of the engine. Thus the "damper pulley" or "damper."
 
1/16th to an 1/8 movement on others but one piston not moving seems a little sloppy to me. While I had the head off I would at least put new bearings in the bottom end.
 
If your piston moves at all then its not stuck unless a ring has broken. Sounds like you need to pull the pan and check underneath and drive the piston out and hope the cylinder wall isn't scored to bad. let us know what you find.
 

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