601 Main Bearing Question

dm2237

Member
Hello, I'm working on the knock on the front of the 601. Looks like the timing gears are worn. Thought I would check the main bearings while I had it apart. Using plasticgage, I found the mains to be between 0.0030 and 0.0040, which is outside of spec for them. I'm trying to figure out what bearings are in it. The part number looks like EAA 6331, but that doesn't match anything I've been able to find. Anyone know what they are? Thanks, Dan
 
EAA 6331 is the Ford number for the "liner, main bearing" https://external_link.com/engine-assembly-inside-567336293/

Most times the bearing will be printed or stamped with something like 'STD' (standard) .010 (ten thousandths oversized), etc. If there's nothing on the shell you are looking at, perhaps you can carefully roll the corresponding shell out of the block and find it there.

What about the rod bearings? If they are standard, likely your mains are too. If oversized, likely the crankshaft has been turned and it would be uncommon to turn just the rod journals.

If I were looking for a knock, I'd look harder at the rods than the mains. .003-.004 is a bit loose, but not by much.
 
EAA 6331 is the Ford number for the "liner, main bearing" https://external_link.com/engine-assembly-inside-567336293/

Most times the bearing will be printed or stamped with something like 'STD' (standard) .010 (ten thousandths oversized), etc. If there's nothing on the shell you are looking at, perhaps you can carefully roll the corresponding shell out of the block and find it there.

What about the rod bearings? If they are standard, likely your mains are too. If oversized, likely the crankshaft has been turned and it would be uncommon to turn just the rod journals.

If I were looking for a knock, I'd look harder at the rods than the mains. .003-.004 is a bit loose, but not by much.
 
EAA 6331 is the Ford number for the center bearing - enter that number into google search and there's a 'fix your ford' site with diagrams and numbers. This site won't let me post a link to there.

Typically bearing shells are printed or stamped with something like STD (standard), or .010 (ten thousandths oversize). If you don't see that on the shell you are looking at, perhaps you can carefully roll the corresponding shell out of the block and find it there.

What about the rod bearings? If I were looking for a knock I'd look there before the mains. If they are standard, likely your mains are too. If they are oversized then the crankshaft has been turned and it would be uncommon to turn the rod journals and not the mains.

.003 is max recommended clearance if memory serves me. .003-.004 is loose, but not terribly so.
 
I'll check the upper portion of the bearing to see if it has a size on it. I didn't see anything on the lower portions I checked. I'm checking the bearings because the tractor only had 20 lbs of oil pressure the last time I had it running. It stayed there for quite a while, then improved to @ 35 or so. I had never seen it do that before. I thought it would be a good idea to check them while I had it opened up. I'll also check the rod bearing clearances to see what's there. Thanks for the replies.
 
I agree. Mains would be a low pitched wong wong kind of ting whereas rods would be higher pitched. Also mains would talk to you
under load more than rods. Not an expert but this my limited experience. Oh one other occurrence was a 4 cyl. 4000 I bought for
a song non-running so there were no audible clues on this one. Owner said it had no oil pressure. Hoping for the best I got the
worst. Rear main was toast.
 
I bought this tractor @ 18 months ago at a local auction. It was sold as a running, driving tractor. But they couldn't get it to start the day of the sale. I paid @ $1550 for it then. I found the battery was installed with a negative ground, and it was stone dead. It started life as a 601 ss, but the complete rear half of the tractor was swapped out with an 860. It didn't have any oil in the rear half of the tractor at all when I got into it. It didn't take much to get it running. Now I'm searching for the knock that I found. Still don't have much into it yet.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top