Recently purchased cat D9g tractor, it runs great and has good oil pressure and has been a great machine thus far, have been told by several people the only real Achilles heal of these machines is the crankshaft failing, is there anything to keep an eye on or do they just fail randomly. I’d like to look after it as another crank would set me back 20-30k that I can’t afford at this time. Thanks
Do not know anything about the crankshaft, but years ago I had a contractor here with a D9G and D9H and they had emergency fuel cut offs fitted as he said the D353 had been known to take off, although blocking the air intake is a better way to kill a runaway motor.
When you service the engine take the old oil filter and cut the top or bottom off and pull out the pleated cartridge. A tubing cutter works well if you don't have a filter cutter. Cut a piece of the pleated paper out the width of your vice and 3' to 4' long and squeeze the oil out of it with the vice and wipe the oil away with rags. Loosen the vice and the paper will "dry up" make sure to keep track of which side was the outside. Stretch out the paper and look for metal particles in it. A few small particles are normal. If you do this every oil change one day you find a large amount of particles in the pleated paper that will give you an early warning of something that is failing in the engine. I used to work as an engine tech in a truck and equipment dealership. I used to tell customers with high hour engines drain their oil filters and bring them to me so I could cut them open. I caught a lot of failures before they got very expensive. Terry
Usually they threw a rod thru the block. A tractor that is 50 to 60 years old is a crap shoot at best. A total rebuild with a crank and block work would be closer to 70k. If you don't have any records on this tractor roll in a set of rods and mains bearings . Good luck Bob
And while rolling bearings, check your crank thrust. Consider regular oil sampling and follow Mekanik’s advice.
Thanks for the feedback, I'm thinking in the next hundred hours or so I will do an in chassis engine rebuild so I know where I'm at with the engine and I can see what condition the crankshaft is in. wow 70k for a rebuild is a lot, I'm thinking that would mean parts and labour plus a new crank and block work. I doubt ill be spending near that as I do all my own mechanical work.
If you’re on a budget,and the tractor engine works well enough for its age,then simply pull the sump off,totally replace the oil pump and shaft drive,then pull a few main and big end bearings. If it’s not using too much oil,then a new set of bearings in the mains and big ends and an oil pump and shaft would be good. You may be suprised,the bearings could be just fine,but I’d still do the pump and drive shaft at all cost. There are plenty of good non oem parts suppliers around that will be suitable for your old D9. Make sure you are comfortable with your level of knowledge in judging if your bearings are good to go back in. If I’m doubt,pay someone that has a good reputation to help you with it once the sump is off. This is crucial.
One last thing,I allways change oil and filters every 250 hours on my dozers using Cat oil and filters
I had that happen, a run away, just used the compression release to stop it. Big thing that can cause problems is an oil pump stopping.