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NeverEnough
10-03-2016, 09:33 PM
Hello to All, I recently purchased a D4-7u that had been sitting for quite some time. I got the ol' girl home and found a leak in the oil cooler. I clamped off the oil cooler lines and pulled the bypass spring and plunger out. I did an oil change while completing the oil cooler job. I cleaned the carb and tank on the pony motor and it ran like a top. Also, drained and cleaned the diesel tank. Got the diesel motor started and it too ran like a top. SO, on to the issue, I recently had the dozer running and doing some very light pushing. The machine ran great the whole time no issues or anything. I completed my task and let the dozer set at idle for quite awhile to cool down. After it had cooled down, I shut it off. The other night I went out to move it and my pony motor and diesel appear to be locked up. I have no clue where to start looking. When starting, once the diesel engine starts I shut the gas off to the pony and let it run out so it doesn't flood. Pulled the spark plugs on the pony and nothing in the cylinders. It got too late to dive much deeper into it. Any help would be appreciated. Thanks in advance.

cojhl2
10-03-2016, 10:23 PM
Hello to All, I recently purchased a D4-7u that had been sitting for quite some time. I got the ol' girl home and found a leak in the oil cooler. I clamped off the oil cooler lines and pulled the bypass spring and plunger out. I did an oil change while completing the oil cooler job. I cleaned the carb and tank on the pony motor and it ran like a top. Also, drained and cleaned the diesel tank. Got the diesel motor started and it too ran like a top. SO, on to the issue, I recently had the dozer running and doing some very light pushing. The machine ran great the whole time no issues or anything. I completed my task and let the dozer set at idle for quite awhile to cool down. After it had cooled down, I shut it off. The other night I went out to move it and my pony motor and diesel appear to be locked up. I have no clue where to start looking. When starting, once the diesel engine starts I shut the gas off to the pony and let it run out so it doesn't flood. Pulled the spark plugs on the pony and nothing in the cylinders. It got too late to dive much deeper into it. Any help would be appreciated. Thanks in advance.

Both locked up, seems highly unlikely. How did you know the diesel was locked up if the starting engine would not run?

Seems like we need more explanation.

dpendzic
10-03-2016, 10:33 PM
make sure the transmission is in neutral, main clutch disengaged, pony pinion and clutch disengaged and try turning over the pony make sure the pony has oil in the crankcase

NeverEnough
10-05-2016, 11:30 AM
I have a 955k that I hooked up and tried pull starting. Anytime I would engage the hand clutch to the transmission the tracks wouldn't turn. Obviously didn't try that too many times. This seems really strange to me like something internal is jammed up between the two engines.

Garlic Pete
10-05-2016, 12:34 PM
I've had success pulling D7s and D8s with the pony engaged. The diesel usually spins and immediately kicks the pony pinion out. I have had a D2, however, where the main engine wouldn't rotate with the pony engaged. I kind of think the horizontal pony engine machines have a hard time getting enough mechanical advantage to spin the diesel by towing with the pony engaged.

Assuming your 955 didn't have any other problems, I would suspect that the pony being engaged was preventing the main from spinning, causing the tracks to slide. As for your D4, I'm confused. I can't imagine how both engines could have frozen up at the same time. If the engines are both fine, but the pony pinion happens to be engaged, you'd have trouble moving the main, but the pony should be able to start, by rope or by electric start, with the pinion engaged. I've done both, with the starter or my rope simply spinning the pony and the main at the same time.

Do you have any slack or movement in either the main or the pony flywheel? If one or the other moves, the amount of movement and how it stops will likely point you in a direction about where the problem lies. I'll bet it is something unusual, but simple, that we're all not thinking of at the moment.

Pete.

cojhl2
10-05-2016, 03:37 PM
did you have the main transmission in ho gear?

NeverEnough
10-05-2016, 08:43 PM
Sorry I wasn't clear earlier. So many thoughts hard to get them down. The tracks on the d4 slid, the 955 was pulling it and the d4s tracks were skidding on the ground. I tried pulling it in both directions using forward and reverse gears. Same result, skidding. I highly doubt that these motors are locked up as we would normally think.(rings, bearings, crank) I am leaning more towards something has come loose and got hung up. The pinion area seems to be the most likely. Thanks again for all the help, I appreciate it. If time permits this weekend I will take a longer look at it. I have a 76 KW I am stretching and restoring in the shop right now.

Rome K/G
10-05-2016, 09:56 PM
?????????? did you check the coolant In the radiator? if its way down coolant may have seeped into one of the diesel cylinders overnight and locked it up. A prechamber may be leaking coolant or it may have a cracked head.

catsilver
10-06-2016, 05:07 AM
Its a waste of time trying to pull start a D4 in first or reverse, the tracks will slide unless you have very good traction, use top gear and only at walking pace, I've started a 7J like this, with a 4 ton lift truck on a concrete floor.

NeverEnough
10-06-2016, 07:34 PM
Came home today from work, barred the pony motor in reverse and it loosened up. It was still engaged to the diesel. Pinion hadn't released. Thanks to everyone for all the help. This winter I will get into it and do some TLC.

Rome K/G
10-06-2016, 07:38 PM
Good deal!