1920 Cranks - Won't Fire

[Jerry/MT]

Good Info Jerry, I wish Todd had a less non invasive option. I agree the head has to come off first before going further after a compression test.

jc,

So do I but the compression test is will guide him. I hope for his sake it's just rings. Some of these engines have been over fed with starting fluid and have broken rings which can mean scored bore or liners and broken lands. if he finds piston crown damage then the injecors ought to be checked for leakage.

 

[toddwulf]

OK Group - Appreciate everyone's input on this stubborn issue but the tractor has been pressure washed and is in the garage to begin work on removing the head and seeing what it looks like inside. I will post pictures of the process, in part so we can refer back to put it back together but also to glean the collective from the group as we (myself and my tractor partner Michael). As of this AM, oil is drained, Coolant is drained and the intake manifold and exhaust stack are removed.

One of the things we'd also like to accomplish, since we are regarding this as an over winter project is to R&R the clutch and diagnose a 4WD issue. The front shaft is already removed and the clutch issue may be an adjustment issue which we'd like to go thru first before cracking the tractor in half. Ambitious we are indeed.

We have all the shop manuals and a clean garage to work in, a decent tool chest and compressor but have never rebuilt a diesel. Doesn't scare us as if you follow a logical path and outsource what needs to be, we should be fine. Where do we find the best place(s) to get parts for this Shibaura engine?

 

[toddwulf]

Head Removal - 1920 Cranks - Won't Fire

Over the course of the week I started the process outlined in the manual to remove the head. These pictures document that process. We had expected to find a blown piston, bent valve or something obvious given the state of the tractor when it ran. Curiously, there was no sign of obvious catastrophic failure. Here are my notes from the dismantling:

1. Injector #3 - The injector well appeared dirty as if the seal had failed and was not clean like the other 3.
2. The injectors themselves as indicated in the pictured are very dirty, oily in some instances.
3. There was no obvious sign of piston damage, although I did notice the inner and outer piston pairs hit TDC simultaneously making me wonder if it was just a timing issue and somehow the timing got off that was causing all the mayhem.
4. The underside of the head - Valve seats look good as do the valves. The pictures show the various build up (or not) of carbon and what not on the valve seats and compression area.
5. Push rods do not exhibit any outward signs of failure and appear straight.

 

[toddwulf]

Some additional notes after reviewing the pictures. Look from Left to Right, piston #2, the cylinders walls felt more scored than the others. Not gouged though. The shot for the corresponding piston #2 on the head had the most oil residue build up and what appears to be fouling of some kind. Piston #4 had the most carbon build up.

 

[toddwulf]

 

[Hooked_on_HP]

#3 cylinder is in bad shape. It appears that the rings are broke and put the groves in the cylinder walls. You will have to take the block to a machine shop to be bored. You will have to bore all 4 cylinders and replace 4 pistons.Here is a link to a place that handles Shibura parts. I have never used them I just ran across the link and saved it Industrial Engines And Parts, JT Services Inc. Perkins Diesel Engines, Isuzu Engines, GM Industrial, Wisconsin and Continental Diesel Engine Parts, Caterpillar, kWiet Power
Bill

 

[toddwulf]

I love this tractor. It's a 4WD model so to drop the oil pan, " remove the front axle and carefully slide it forward and out of the way" . Guess that means a clutch job and whatever other maintenance stuff you do when it's completely disassembled, you just add to the list. Guess I need to install that wood burning stove in the garage for the over winter work!.

There does appear to be more significant cylinder wall scoring on two than initial inspection showed. Dropping the oil pan to look for metal fragments and get access to the rods to remove the pistons. Couple of questions. Could we not just replace one piston ? Does it have to be all four? Could we not just re sleeve the cylinders?

 

[Robert_in_NY]

Since you pull it in gear, how are you gonna stop it if it fires off and starts running up your backside? Pullin' is the easy part.

I know this is an old thread Jim but I read your post here and it reminded me of something. I buried my TN while discing. It was a field off the end of one of my vineyards. I had no help and needed the tractor. I walked home, grabbed the 1920 and a chain. Went back and hooked on. I had the TN unhooked from the disc and chained to the 1920 which was actually in a grape row. I then put the TN into a very slow crawl at idle and as the tires spun I jumped on the 1920 and started pulling. As soon as the TN started to climb out of the whole I kicked the 1920 in neutral, jumped off and ran back and kicked the TN into neutral. A long, long chain is very handy when attempting this incredibly stupid stunt. But I wasn't worried about the 1920 being hit, in an open field you just turn it out of the way. I was worried about the TN running into the grape rows and either destroying the ends of a couple rows or damaging the tractor. I lucked out and managed to get it done without injury or death but I would not recommend anyone do it unless they have no other options.

Once the TN was out I hooked the chain to the disc and it pulled out easily so I rehooked and went back to work. Always pull in a slow gear if possible, if you can't then don't attempt it.

 

[toddwulf]

Ok. Axle pulled and pan dropped. Definitely fragments from a shattered ring in the pan. Will have to pull the pistons and see if one or more is the issue, but as others have indicated, better to R&R all the rings while your in there. I'm hoping I can get away with just the rings. How do I tell if I need to re sleeve the cylinder(s)? The pistons look fine. Can I possibly hone them?

On the front axle, the drive pinion shaft is loose and sloppy. Thrust washer was not present. There is about 1/2" of play in the shaft in all directions.

 

[Hooked_on_HP]

Ok. Axle pulled and pan dropped. Definitely fragments from a shattered ring in the pan. Will have to pull the pistons and see if one or more is the issue, but as others have indicated, better to R&R all the rings while your in there. I'm hoping I can get away with just the rings. How do I tell if I need to re sleeve the cylinder(s)? The pistons look fine. Can I possibly hone them?

On the front axle, the drive pinion shaft is loose and sloppy. Thrust washer was not present. There is about 1/2" of play in the shaft in all directions.

Your engine does not have sleeves. You would have to have the block bored to install a dry sleeve and then bore the sleeve to size. If it were me, I would get some one to measure the cylinder bores with a cylinder bore gauge. This will tell you how much wear you have and if the cylinders are out of round. Then decide what route to take.
Bill