Logging with my Jinma 254

[mitchash]

I logged for a week with my Jinma 254 using Norwoods Log Hog three point hitch plate and the tractor worked great! I was really impressed with the power and traction it has! I put over 40 hours on it with only minor problems. The fuel gage stills dosen't work (never has since I bought it) I think it's a bad sending unit. The dif lock dosen't work, is there a way to adjust that? The book says there is but the linkage didn't look like anything I have. After I had only 4 hours on it it started knocking and smoking really bad, I thought I blew it up (I'm much more use to gas engines), I shut it down checked all the fluids, the oil pressure and temp were all good before I shut it down. I started it back up and it was fine and never did that again. I'm thinking there was something in the fuel that made it "diesel knock". It seems to shift a little hard. Other than that it worked really well and I pulled some big logs with it. The only thing I wish I had got was the shuttle shift, I never needed the creeper gear and it would have been nice to have more reverse speeds.
Ash

 

[greg_g]

Can you be a little more specific about the diff lock issue? There's no adjustment really, it's either engaged or it's disengaged.

//greg//

 

[RonMar]

The difflock like the 4X4 engagement uses a flat faced 3 tooth "claw" to engage/disengage. The claws look like matching radiation symbols or a pie cut into 6 pieces with 3 pieces(every other one) missing. Unless they are aligned, they will not engage. To align them, you need a difference in wheel speed. In the case of the rear difflock, you need to either have one rear wheel spinning or be moving in a circle so both wheels are rolling at different RPM. Just hold gentle pressure forward against the lever and when they align, the lever should fully engage. The difflock lever pushes in a spring loaded rod. Mine had a lot of paint on it and was a little difficult to engage and slow to disengage at first untill I cleaned it up.

The 4X4 uses exactly the same type claw, just hold gentle pressure up on the lever while rolling till the claws align and in she goes. The slight differences in gearing and wheel diameter make for slightly different wheel speeds when rolling so the claws will eventually align. These differences in wheel speed are why you must ALWAYS be on soft ground when using 4X4. If the wheels are not allowed to slip in the soil, the stresses involved will be absorbed by the gears and damage WILL occur. This is also why 4X4 is a little harder on the grass and the front treads tear up the ground a little more in turns.

 

[greg_g]

The 4X4 uses exactly the same type claw, just hold gentle pressure up on the lever while rolling till the claws align and in she goes.

Um, no. It doesn't. That's what the transfer case is for. The front diff and the front drive shaft and the transfer case drive gear are all turning whenever the front tires are rotating, regardless of 2wd/4wd lever position. That lever ultimately moves a sliding gear in the shuttle box. In 2wd this sliding gear is idling on its short shaft. When moved to 4wd, the sliding gear completes the drive connection between the transfer case gear and the transmission. The transfer case drive gear then becomes a driven gear.

The technique is as you describe though. There must be slight rotational movement of the front wheels so that the sliding gear can mesh with the transfer case gear.

//greg//

 

[RonMar]

Um, no. It doesn't. That's what the transfer case is for. The front diff and the front drive shaft and the transfer case drive gear are all turning whenever the front tires are rotating, regardless of 2wd/4wd lever position. That lever ultimately moves a sliding gear in the shuttle box. In 2wd this sliding gear is idling on its short shaft. When moved to 4wd, the sliding gear completes the drive connection between the transfer case gear and the transmission. The transfer case drive gear then becomes a driven gear.

The technique is as you describe though. There must be slight rotational movement of the front wheels so that the sliding gear can mesh with the transfer case gear.

//greg//

Um, Yes. It does Greg. The 200 series does not use a sliding gear. It is a 3 tooth claw. Part numbers 29-35 in this first pic from Johns site are the 4X4 engagemnent mechanism. Part 35 is the claw itself(rear view) which is slid on its shaft by part 34 and the rest of the lever mechanism. That shaft is directly geared to the front diff via transfer case gears that are always engaged. http://www.johnstractor.homestead.com/files/ClutchHouse.jpg

When you lift the 4X4 lever Part 35 in the above pic slides to the rear and engages with part 42 in this next pic(lower left) that is on the end of the front end of the transmission output shaft and direct coupled to the rear diff.
http://www.johnstractor.homestead.com/files/DriveGear.jpg

I was incorrect earlier, the difflock claws(130,132 in the last pic) have 4 teeth, not 3. The same engagement theory applies though, they are hard coupled to their respective wheels and must be rotated into alignment by wheel movement to engage.
http://www.johnstractor.homestead.com/files/DriveGear3.jpg

 

[greg_g]

Um, Yes. It does Greg.

I get the feeling that you're basing your convictions solely on trying to interpret a parts manual diagram. I have no idea why you linked to a creeper, the 200 Series 2wd/4wd select lever is one box back - on the right side of the transmission housing. And the transfer case is directly below the transmission housing. Or at least they used to be, back when I owned that pair of 254s. Have you actually performed a hands-on disassembly of this particular shift mechanism yourself Ron?

But since the front end doesn't use diff-lock in the first place, I'm hoping the OP will simply overlook this little disagreement.

//greg//

 

[RonMar]

Greg
I know it pretty well as I have been into all of mine except the rear section under the 3PH during my initial inspection and tracking down a unusual noise. I was intrigued by the claw assembly so I looked into it closely.

"the 200 Series 2wd/4wd select lever is behind the gear shift lever - on the transmission housing cover"

I don't know what tractor you are refering to, but the 4X4 engagement lever on my 284 is on the left side of the creeper case, right by my left ankle when seated. You lift it to engage 4X4. You can see the claw and linkages with the creeper case top cover removed and it is just like that in the pics I linked to. In that creeper case pic, part number 39, the shaft that the claw slides on, has a little gear in the middle of it. That gear spins the intermediate gear down in the transfer case...

"But since the front end doesn't use diff-lock in the first place, I'm hoping the OP will simply overlook this little disagreement."

Ditto

 

[Ranch_Hand_Supp]

I logged for a week with my Jinma 254 using Norwoods Log Hog three point hitch plate and the tractor worked great! I was really impressed with the power and traction it has! I put over 40 hours on it with only minor problems. The fuel gage stills dosen't work (never has since I bought it) I think it's a bad sending unit. The dif lock dosen't work, is there a way to adjust that? The book says there is but the linkage didn't look like anything I have. After I had only 4 hours on it it started knocking and smoking really bad, I thought I blew it up (I'm much more use to gas engines), I shut it down checked all the fluids, the oil pressure and temp were all good before I shut it down. I started it back up and it was fine and never did that again. I'm thinking there was something in the fuel that made it "diesel knock". It seems to shift a little hard. Other than that it worked really well and I pulled some big logs with it. The only thing I wish I had got was the shuttle shift, I never needed the creeper gear and it would have been nice to have more reverse speeds.
Ash

Ash,
RonMar in my opinion has given you a good description on how the difflock & 4x4 engagement works on the 254's I have been into.

..... the oldest I have been into has been a 2003 model and has been the same set up on the ones I Import to present.

There is an adjustment at where the fork shaft comes out the side under the lever. You can adjust the throw.

You have to bend down and look up..... you can see it if it not covered in mud..... maybe spray and lube shaft while moving lever and make sure the shaft is not sticking where it slides through the housing.


Your knock [I bet] was an injector that stuck and unstuck itself. It will sound like the bottom end is coming out of it !!! I would run a good cleaner/lube in the fuel and maybe you want have to replace the injector if that was the cause.

Make sure clutch is adjusted properly on the trans shift.

Ronald
Ranch Hand Supply