Not a good day.. My 3T D7 out of the blue began making a knocking noise. It’d been normal fine until I noticed the noise. I was only a couple minutes from park area and headed that way. It was very sickening loud when I shut it down. My friend has a newer model D5 and was helping me clear. He asked if I’d ever sent an oil sample to be analyzed. Pics show dissected oil filters with steel shavings .. I think it would load to transport.. but a question I have.. is it possible to replace a crank in frame? All else on this machine seems good shape. The D5 was busy and going around a larger tree.. he can fell this size with a little more effort digging roots etc just takes a bit longer. On the way to park I veered slightly to give it a push and down it went. Hopefully it’s not the last. Wondering anyone have similar experiences?

Knocking Noise - never a good sound. SHUT IT DOWN IMMEDIATELY
IF - you have a main or rod bearing gone, you risk way too much to be running it at all. Not even to load!
Winch it on - You have another Cat there, you can drag it to the truck.
Assuming it is a rod bearing gone bad, you break the rod and throw it through the block or pan, then where are you?
You will not know how far you have to go until you do find the problem.
Nothing is going to be easy - everything is HEAVY.
I can not remember - you might have to pull the equalizer spring to even get the pan off?
Certainly will want to drop the dozer.
CTS

dont run it at all. chain the blade up with a come-a-long (lever block)and push or winch it on the trailer. if you work the hydro lever as you lift it will raise easier. hopefully it hasnt ovalled the big end journals much. the crank can be ground to a true size and undersize bearings fitted provided this hasnt been done too many times before. any good engine reco shop can do this work. its much easier to work on a engine out of the chassis.

Many years ago there were adds in farm magazines of guys that would clean up your crankshaft in place. I don't remember knowing of anyone that used the service. But since the adds have been gone for years, my guess is it was not the most cost effective way in the end.

Spoke with a retired Cat mechanic -
You will be much better off pulling the engine from the chassis -
Save you a lot of time and grief -
CTS

In frame on a 3T is like building a ship in a bottle!

ray that tech is still used but its mainly on big engines such as big marine diesels in ships where removing a engine or even the cam shaft is major surgery.

Thank all for your input. I’m unsure when but know I’d like to attempt this possibly with the right help. Thx again.

Very common in the 70’s and 80’s to turn a rod bearing journal if only isolated damage to crank. Same mobile machinist would also cut counter bores upper and lower and fix head head bolt threads.

Steeltracs I’d like to see a mobile machinist still today doing their work.. thanks for sharing