TY290 Piston removal (the saga begins)

[commrad]

Bought a Farm Pro 2420 the other day that was getting oil in the water. The owner explained that he bought it from a guy who had purchased it new around 2000-2001, the original owner was supposedly bush hogging and it died in the middle of the field with water in the oil. The guy I bought it from thought it was the head or head gasket and bought it, said he had to load it in the middle of the field and help unhook the bush hog. If any of this is true I will never know but I feel like the guy was being honest.

He included a near complete set of gaskets, minus the head gasket and valve cover gasket and said that he had removed the head, had a local shop (major city) check the head for cracks and replace the valve guides.

I thought, eh, no problem, pop the liners and replace the o-rings since the speed it was loosing coolant was way too fast for any cracked block I'd ever seen.

Tear down went extremely easy as expected until I got to the pistons. I decided to start with the rear piston. First off the rod bolt seemed to be torqued to around 200 foot pounds but I did get them loose with a cheater bar about 3 feet long. The rod cap was very difficult to remove and I actually had to drive one of the rod bolts completely out before it would break free from it's home. Once it did slivers of bearing dropped on my head. Ahh, sigh, so much for some gaskets and o-rings to fix it. As I'm turning the crank to allow the piston to be pulled I notice what looks like a soldered or brazed oil hole. Sure enough there is no oil hole. Apparently with the rod bolt over tightened by king kong with an impact gun had allowed the oil hole to shave the bearing, ironically I believe the cheap Chinese bearings may have actually saved the crank. There are no gouges, only high spots of soft bearing material which may clean up.

Now the trouble begins, I work night shift so on my days off I'm up all night and working in the dark with over head lights, definitely not the all filling sun light of day time. I tried to pull the piston out the top with no results and notice one side of it where the wrist pin goes through that the piston appears to have hit some thing at some point. I worked for several hours before I finally thought to check the remaining rod bolt, sure enough it was hanging over the edge of the rod preventing it from coming out of the cylinder. Tap that bolt out and it slides right out. After the piston is removed it like the piston came too far out of the cylinder at the bottom of the stroke and twisted before being rammed back into it's bore. Crap, this keeps getting better. The cylinder o-rings can be seen laying on the ground, hung in the oil strainer and dangling from between the liner and the block.

I move on to the front piston, the rod bolts (nuts) seem normally torqued, the rod cap came off as it should once breaking the vacuum of the oil, the piston and rod slide out normally and easily. The front sleeve looks longer than the rear? Huh? The front one measures 6 3/4 inches, the rear one........ 5 5/8 inches? WTH!? Go back and look at the damage to the piston, it looks like the wrist pin was dropping below the bottom of the liner and the guy finally put enough load on it to cause the piston to cant just enough to wedge everything together, prob the reason the rear cylinder o-rings are dangling the way they are.

I'm just praying I can clean the crank up enough to use it, don't really want to have to put a complete rebuild into a tractor that I only plan to bush hog with while I mechanically restore my little Yanmar. Just moving this thing onto the trailer I really like the idea of the creeper box, never had one of those and REALLY liked it. Hope this thing isn't a lost cause but even with all it's problems it ran great loading it onto the trailer.

[sadixon49]

So, do you believe that the engine was built wrong at the factory, or that someone tried to rebuild it, at some point, and used the wrong parts?

steve

[commrad]

Originally Posted by sadixon49

So, do you believe that the engine was built wrong at the factory, or that someone tried to rebuild it, at some point, and used the wrong parts?

steve

Some one had been into the top end but the bottom end looked completely unmolested, factory gaskets that were very stuck and painted, half the oil pan bolts were rusted in place. Pretty sure it was built wrong at the factory, the short liner.

[commrad]

I decided to try to pull the rear sleeve this evening but didn't have a puller.

I had noticed earlier that the rod cap was partially machined to clear the bore of the cylinder and since I will be replacing the rod any way for good measure since there was a mechanical interference issue on that cylinder it was the base for my sleeve puller.

Off to Home Depot for some all thread, they sell 3/8x12" that worked perfectly and a nut kit called build a bolt or something like that. Included 6 nuts, and washers to go with them.

Off to Tractor Supply for some bar stock. they didn't have a piece as thick as I wanted, only around 1/4x2". I cut two pieces about 10" long, laid out the bolt holes and in the drill press they went.

On the tractor I brought the #2 crank throw to top dead center, reached in from the top and balanced the rod cap on the crank shaft. Then I took two nuts and placed on one end of the all thread and lock then together to prevent them from backing off, repeated for the other. I then crawled under the tractor and very carefully started one of the rods through the balanced rod cap, slid it trough, reached around to the top (not easy) and used a rubber band to secure the all thread to a head stud then repeated for the other one. Next I ran two of the head nuts down on adjacent suds even with the top of the stud, ran the rod through the holes in the bar stock and put the nuts on. Next I started the rod cap into the bore, made sure every thing was lined up and started tightening the nuts 1/2 turn at a time until I had bowed the bar stock about 1/2" in the middle. Next I used a hand held propane torch to heat the liner, I got it hot enough that water was boiling out between the liner and the bore, allowed to cool for a while and it still had not moved. Tapped the liner with a hammer hopping the vibration would free it, nothing. Turned both nuts 1/2 turn each, nothing, 1/4 turn each and POP, repeated until the liner was free.

Now the really odd part. There were pieces of bearing and o-ring in the oil sump, NO cast iron or steel of any kind, not a trace. The bottom of the liner is gone, broke off just below the top o-ring grove. judging by the build up around where the bottom of the sleeve was it has been like this from day one. I still believe that this thing was built this way at the factory and the one o-ring held until the tractor was put under enough load to cause the piston to **** slightly sideways and be wedged into the bore, this interference crushed the rod bearing and caused it to flow into the oil hole on the crank shaft. The side load on the sleeve allowed the o-ring to be forced out of the grove that had less than 1mm of metal to support the o-ring in the spot it blew out.

[commrad]

Included is a picture of the damage caused by cavitation.

[commrad]

Had to add a little more support on the front cylinder.

As you can see there is a lot missing from the rear cylinder but no damage to the crank, block or any signs of the missing part of the sleeve ever being in the engine.

If that much of the sleeve had dropped into the engine there would be signs of it some where and I have looked every where and can't find any.

Also the bore where the o-rings rest, the front cylinder had two distinctive black lines where the o-rings were, the rear, only one.

The tractor is from the time period when Jinma moved to a new factory. I wonder if some one dropped this sleeve and it broke then just installed it anyway.

[commrad]

I haven't done anything else as of yet. I'm in the process of buying a house and it has put a serious strain on extra cash for projects.

Had to spend my "tractor money" for appraisal and stuff like that. Hopefully before long all that will be over with and this will turn into an engine build thread.

On a plus note, we asked for more than the selling price of the house and my wife demands that I buy a new bush hog and "man cave" so my RC planes and reloading equipment aren't in the house. She did say I would have to buy my own heat and air unit though, guess she forgot the 2.5 ton unit here is mine.