Purchased a D7G about three years ago and been running it in my small earth moving business since then. During that time I have had a few improvements and breakdowns. The first was a change from a strait blade to a full U blade. Due to the added weight of the U blade I was in need of rippers to balance the machine, picked them up last summer, pushing my total weight to 56,000. Then the problems started. Last July I found out that I had a bad dead axle on the left side, and it had been bad for a while--probably why they sold it for such a good price. Anyways after that no serious problems until this spring. This is just a little back ground for what is coming, this spring i had to do the first major repairs on the engine, basically did a in frame overhaul. Should have pulled the engine and did a complete overhaul but didn't have the time or the money to do pull it. This was back in March. Since the overhaul I have put about 30-35 hours on the machine, even changed the oil at about 20. Last Thursday I fired it up and used it for about two-three hours cleaning out a trash pit, then parked it. Friday afternoon rolls around and start it up to collapse the pit, as I was busy that morning. The engine fires just fine, sounds great like it always did. It idled for maybe 10 seconds then the most horrendous squeal starts from the engine. The RPM start dropping real quick and I shut it down as soon as possible before it dies. I think I lost the number one main bearing. This leads me to the reason for this post, I don't have the time to wait for someone to tear down the engine and fix it. Instead I was wondering about just buying a whole engine and swapping it out. From what I can find online it looks like a complete engine remanufactured will cost me about $9,000 for a 3306pc, or for about the same I can go for a 3306DI. I was wondering if the 3306DI would be compatible with my crawler? More specifically would the front mounts and the bolt pattern for the torque converter. I was also wondering if the added horsepower of the DI, about 27 horse would cause any damages to my machine. I liked the idea of the added power since the dozer is getting so heavy. Thanks in advance.
If you are changing the engine you will be pulling the rear housing off right up to the block because the new engine won't come with the rear housing that the d7g has. The housing has accessory drive gears for your hydraulic pump . The back of the block should be the same on both engines with only an oil feed hole that might need to be plugged. The rest of the engine should be the same. It also depends on governor speed settings on the new engine.
Topper I would calm down a good bit, then check out the Vee Belts etc possibly also cut the oil filter and look for sparkles, it might not be the motor failed, the crank bearings can be swapped out in frame on this mount? I have known an alternator/generator lock up and cause the " I have a knackered crank" feeling. tctractors
Yeah, tctractors your right I was over reacting, this morning I went over to try to see what had gone wrong, dropped the belly pan and took a look up in there, I was planning on dropping the oil pan and have a look at the crank as well but found my problem. I found a bolt had come loose from the front mount, right there at the front of the block by the drive pulley and the harmonic balancer. Anyways one of those bolts had worked free and had wedged up against the back side of the drive pulley and pulled the engine down. So I torched out the bolt and hit the switch, problem solved. It was just a little hard to believe that one small 1/2 bolt could keep the engine from running, or even from cranking. Thanks for the heads up to look for a simple mistake. I just figured that I had done something wrong when I did the in frame overhaul as it was the first one I had ever done on a diesel engine, and when ever I told my local mechanics and cat techs they thought it sounded like a main bearing, guess I got worked up over nothing.
Welcome to Diagnostics 101. Now sit back, pour yourself a cold one, and toast your good fortune.............
Good fortune indeed. Has the bolt done any damage to the balancer? I am not familiar with that exact engine, but I would be taking a good hard look at the balancer in case the bolt has done damage. It is not unheard of for a damaged balancer to lead to a broken crank.