engine knock found
Posted: Sat Dec 04, 2021 9:18 pm
So, the 48 cub that I recently bought with the slick knock got some attention today, and you all are not going to believe this.
I wanted to try and trace down the source of the knock, so off with the oil pan.
Once I got the pan down, and started to roll it around with the crank, I noticed that the front end of the crank moved forward some.
On closer inspection there is a break, across the crank right behind the front main. The crank would literally be in two pieces, if not for the mains holding it in place.
Here is the weird part.. This engine really made very little noise, and it carried very good oil pressure. I have never taken a running engine apart on anything, that had a broken crank.
The good news is that the rest of the engine looks good, from what i can see. I pulled the rest of the mains down, and number one rod, and so far so good.
So I will take the engine out, and tear it the rest of the way down, and look thinks over.
Apparently the engine has not run much in this condition, and the fact that its a low RPM engine apparently save the engine from coming apart.
I hope all the rest is ok, and will follow up with more info, after I get the engine out of the tractor.
Now for the $64,000 question... So was this was a casting flaw, or an abuse issue, and if so what the heck where they doing that cause this?
Has any one else has ever encountered a problem with cranks shafts in the little cubs?
I wanted to try and trace down the source of the knock, so off with the oil pan.
Once I got the pan down, and started to roll it around with the crank, I noticed that the front end of the crank moved forward some.
On closer inspection there is a break, across the crank right behind the front main. The crank would literally be in two pieces, if not for the mains holding it in place.
Here is the weird part.. This engine really made very little noise, and it carried very good oil pressure. I have never taken a running engine apart on anything, that had a broken crank.
The good news is that the rest of the engine looks good, from what i can see. I pulled the rest of the mains down, and number one rod, and so far so good.
So I will take the engine out, and tear it the rest of the way down, and look thinks over.
Apparently the engine has not run much in this condition, and the fact that its a low RPM engine apparently save the engine from coming apart.
I hope all the rest is ok, and will follow up with more info, after I get the engine out of the tractor.
Now for the $64,000 question... So was this was a casting flaw, or an abuse issue, and if so what the heck where they doing that cause this?
Has any one else has ever encountered a problem with cranks shafts in the little cubs?