last few pics look like grit or a nick, but the first look like bearing failure, or bearing seizing to journal.Mace said:
Mains sticking to crank...
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Hi Steve.
That number four bearing is burnt from lack of oiling. Like we discussed before, that bearing is the furthest from the supply point and it (and/or #3 main) are normally the first to go when oil flow is not sufficient.
I think I'll go with a low speed failure as opposed to a high speed. Fits in with what the owner says about when it quit. Overheated and/or overaged oil of too thin a grade to start with. Probably loose clearances too. Possibly a pump that was not putting out as much oil as it should but unless the rotors or cap are severely scored from debris that made it's way in past the screen then that would be very unlikely.
As for number 2 main... That is one hell of a groove. Looks like there was a piece of debris lodged in there for a while. Or a heck of a burr pushed up in the crank journal surface (along side a dent maybe). But didn't you say that there was not damage to the crank surface?
IF the crank is not damaged, then I'd probably try just slipping new (standard sixed bearings in. I don't think I've seen that much bearing damage without crank damage though. At the very least plastigauge it after you put the new bearings in.
And check the oil pressure with an accurate gauge before you send it out.
Mark...
That number four bearing is burnt from lack of oiling. Like we discussed before, that bearing is the furthest from the supply point and it (and/or #3 main) are normally the first to go when oil flow is not sufficient.
I think I'll go with a low speed failure as opposed to a high speed. Fits in with what the owner says about when it quit. Overheated and/or overaged oil of too thin a grade to start with. Probably loose clearances too. Possibly a pump that was not putting out as much oil as it should but unless the rotors or cap are severely scored from debris that made it's way in past the screen then that would be very unlikely.
As for number 2 main... That is one hell of a groove. Looks like there was a piece of debris lodged in there for a while. Or a heck of a burr pushed up in the crank journal surface (along side a dent maybe). But didn't you say that there was not damage to the crank surface?
IF the crank is not damaged, then I'd probably try just slipping new (standard sixed bearings in. I don't think I've seen that much bearing damage without crank damage though. At the very least plastigauge it after you put the new bearings in.
And check the oil pressure with an accurate gauge before you send it out.
Mark...
Ugh - very sad to see...
Thanks for posting this Steve.
Thanks for posting this Steve.
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- #24
nuclearlemon said:
This is a far more common practice than you think Iggie...
Did this on a K19 Cummins back in '93, and a number of engines since...
Talked Dave (Idave) through it on the phone a few months back...
Glad to hear that Ken's engine is still going strong.....as it should.
Mark W-
I have only been able to find any marks on the crank around the number 2 journal....nothing around number 4....I will be under there again today....
Oil pressure WILL be verified before it rolls out.
Thank you for your eyes/time bud!
-Steve
Pull the bigends and see what they look like.
Clean out all the oil galleries, including the ones in the crank.
Check the oil pump - pull the bottom plate and see how worn it is - it may be worth putting a new one in. Even just having the bottom plate machined can help a lot if it's not too bad.
Clean out all the oil galleries, including the ones in the crank.
Check the oil pump - pull the bottom plate and see how worn it is - it may be worth putting a new one in. Even just having the bottom plate machined can help a lot if it's not too bad.
Sorry about the response. I was trying to answer a question on another post and clicked on the wrong one. Maybe that is why it did'nt make sense! Sorry good luck with your engine.
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- #33
So the bearings are at the shop and all measure out to be the same thickness as the ones removed...using a ball-micrometer...or ball mic.
First pic is a ball mic next to a standard mic, notice the curved stationary contact on the end of the ball mic, compared to the standard flat surface.
Second pic shows the ball mic being used.
First pic is a ball mic next to a standard mic, notice the curved stationary contact on the end of the ball mic, compared to the standard flat surface.
Second pic shows the ball mic being used.
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- #34
Oh...and sanding the crank....
First pic is #1 that did not need attention
Second pic is #2 that needed the most, but was really not that big of a deal compared to other that I have dressed...
Third pic is #4, which only had two very small 'spots' that you could catch your nail on, and would not even show up on the camera. #2 was the same way...I could not get the rough spot to turn out worth a s***..#3 main was like #1...no issues.hope to have it running this weekend.
First pic is #1 that did not need attention
Second pic is #2 that needed the most, but was really not that big of a deal compared to other that I have dressed...
Third pic is #4, which only had two very small 'spots' that you could catch your nail on, and would not even show up on the camera. #2 was the same way...I could not get the rough spot to turn out worth a s***..#3 main was like #1...no issues.hope to have it running this weekend.
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When you say that it "would not turn out worth a xxxx", do you mean that you could not get a photograph of it or you could not get it to polish out with the emery cloth? What grit are you using? I wish I had know about this back in 1978 -- I might not have spent the entire summer on foot, but rather in my '75 FJ40. Cool stuff.
With the polishing that you are doing, do you think you could ever get 0.010 under
bearings to work or is that unreasonable to expect?
With the polishing that you are doing, do you think you could ever get 0.010 under
bearings to work or is that unreasonable to expect?
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- #36
Back in post #16, I made comment about some of the things that are just not too stock in the engine/radiator mounting area....
#1 is drivers side engine mount to frame
#2 is passenger side engine mount to frame
#3 is the fabbed radiator mounts
#1 is drivers side engine mount to frame
#2 is passenger side engine mount to frame
#3 is the fabbed radiator mounts
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- #37
rgentry said:
I could not get the picture to turn out....sorry about that.
There is no way that I know of that you could symmetrically refinish the crank with emery cloth to make an oversized bearing fit a crank that needed to be cut .010”...and even if you could you would age years doing it.
I have dressed some pretty bad crankshafts in some Cummins 855, 1710 and Caterpillar 3406, 342 and 353 engines where the crank costs more than the piece of equipment or truck is worth to replace, be dresses like this, and it works fine for many years/multiple in-frames later.
240 quickly around it, and then 320, and will finish it off with a piece of crocus cloth which is around 1000.
-Steve
Kinda fun to see you doing this after you described the process to me last year, Steve. Sure got me running again.
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- #39
rgentry said:
Provided the oil pump is working properly, I do not see any reason why it would not have good oil pressure...the rod bearings do not show any wear, compared to the crap #2 and #4 bearings.