2670 Crankshaft - Need help/advice

Lamont

Well-known Member
Ok. Neighbor's 2670 is down. I'm still thinking about buying either the whole tractor or just parts and engine or parts and parts off the engine. To give a little history on this tractor; it was "rebuilt" about 200 hours ago, top to bottom. It developed a knock, then spun a bearing. Crank was taken down 0.020" and put back together with a NEW rod. Went back to the field and all seemed well until it got into a hard pull in some heavy/damp soil. The knocked developed again and quickly spun that same bearing again. Measured it today to find the damage is right at the 0.030" mark. What do you guys recommend on this one? The turbo has about 200 hours on it. The heads were rebuilt 200 hours ago. Injector pump is definitely good. Has 200 hour pistons, aleeves, rings, wrist pins, rods, (less the one bad one), good hydraulic pump, transmission shifts good, radiator is good. Is the crank salvagable? What's the value of this thing whole or value of various parts? If I don't buy it, it's probably going to the other neighbor's scrap yard and I sure hate to see good parts go to waste. He wants $2500.00 for it, but I can't see it being worth that. However, it will probably weigh out $2000.00 at the other neighbor's scrap yard.
 
that would be a shame to scrap. offer him scrap price. i would almost be interested in it if it was closer and he wanted less. my 4490 had spun a bearing just shortly after a rebuild too. my crank had to be shipped out to the carolinas to get redone. i didnt put more than about 30hrs on it after and i sold it and its up by vermont.
 
I've offered $1650.00 for it, but NO GO so far. He's convinced it will bring $2500.00 for scrap and sticking to that right now. He might be right on the price, but I just can't see it, especially if the crank is ruined.

How far can that crank be taken down and still be reliable?
 
i dont remember what it was. it was a few yrs ago. check allofcraigs.com there might be something. im sure there is a good used cheap one out there. even if everthing else it is good it might be worth a 3rd chance. i would be interested in it if it was closer and cheaper. did dc-741 ever scrap or fix his 2670 maybe he still has his and might have the motor.
 
With what you describe being done, she's worth $2500 all day long. I would check for a blocked oil port. If it was near me, I beat a path to his door with the $2500 pretty fast.
 
Could the crank be taken down to 0.040" or is it ruined with the damage being down to 0.030" mark? I don't even know if rod bearings are available past 0.030" or not.
 
If were talking about a complete 2670 for $2500 with a bad rod journal I would say heck yes it’s a good deal.

Is the Babbitt on the rod bearing pulled or full of metal?

If it’s pulled it was probably too tight when it was installed if it’s full of metal than odds are the crank oil hole was never cleaned out properly before installation.

If the rod is .030 no it will probably need to be taken to .040 before its cleaned up.

P.S. this is along the same subject line but have any of you guys noticed the quality of head and cranked jobs have gone down hill?

Locally we used to be able to get heads and cranks turned now we can’t even get valves ground. It seems like when the old guys retired the quality of work went to heck in a hand basket.
 
(quoted from post at 16:54:07 12/18/11)

P.S. this is along the same subject line but have any of you guys noticed the quality of head and cranked jobs have gone down hill?

Locally we used to be able to get heads and cranks turned now we can’t even get valves ground. It seems like when the old guys retired the quality of work went to heck in a hand basket.

I have local shop has treated me really well. I hesitate to give out information for for fear of causing a backlog. The last 2 cranks have been within .0005" of where I wanted them, I can't ask for any more because I don't have anything that will measure any better than that.
 
.030 is the limit. Some shops have the ability to "spray weld" a journal back to standard or whatever. A good used crank wouldn't be hard to find, but for $2500, look at all the other parts you get.
 
Those 504 crankshafts aren't that hard to come by. $2500 is a cheap price, rough 2670s are in the 7-10,000 range.
 
Agree on blocked oil port thing, rods are lubed thru neighboring main brg journal. Either blocked port in block or crank main journal, possibly main brg installed with wrong half(one w/o oil hole) misplaced in block rather than cap. BTDT
 
Are you wanting to rebuild the 26 or do you have another use for the 504? We have had several cranks welded back to specs with no problems. If the tractor goes to scrap I would be interested in the 504 complete. Give me a call 217-343-1585
 

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