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spun bearing multiple times, help appreciated


twinturboIH1566

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got this international 434, with a 4cyl diesel in it. spun a rod bearing at roughly 7000 hrs. 

sent it to a shop got the block cleaned and so on

i reassembled it with a new crank, pistons, liners, bearings. the whole 9 yards.

within 3 hours of use it spun a rod bearing again. pulled it apart thinking i had done something wrong, everything was correct.

put new bearings in it AGAIN, same thing happened, spun a rod bearing.

 

also it is not the same rod bearing each time, it is a random one. it seems the 2 piece bearing welds itself together and then welds itself to the crank.

 

bearing clearances were checked on both rebuilds and were within spec.

oil pressure was 35-40 psi at all times.

 

Am I missing something or is this just terrible luck?

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what everyone above said. 

I would not just put new bearings in a rod that has spun a bearing. IMHO you need to have all the rods resized to insure they are round and you are getting the right bearing crush

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Did you reuse the rods with spun bearings?  

I would be checking what the dimensions of the rod bearing bore is without the bearing in, with the cap torqued to spec.  Check on the parting line axis, and 90* to that.  If anything, the parting line axis should be a be slightly wider.  If the parting line axis is smaller than the perpendicular dimension, the parting line of the bearing can open up slightly and scrape the oil film off the crank journal.  I would be looking hard for an oiling problem also.

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I did use plasti-gauge.

A brand new crank was put in.

I did not reuse the rods that spun the bearings.

After it spun a bearing with the new crank I sent it to a buddy who works at a machine shop and he machined the NEW crank back to spec.

I could spin the engine by hand with the bearing caps on.

Assembly lube was used.

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Wow sounds like you did your homework too replaced all the parts concerning the spun bearing oil passages cleaned just no rhyme or reason why it happened again that's a head scratcher and assuming rod bolt torque correct too What brand parts were used ? 

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Maybe check oil flow with crank out of it by pressurizing externally somehow.  

Maybe the gauge is getting pressure but is clogged in other places.  Floating chunks of crud or something.

Maybe has ok pressure and not enough volume....

How do you turn the crank back to spec?

 

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8 hours ago, twinturboIH1566 said:

I did use plasti-gauge.

A brand new crank was put in.

I did not reuse the rods that spun the bearings.

After it spun a bearing with the new crank I sent it to a buddy who works at a machine shop and he machined the NEW crank back to spec.

I could spin the engine by hand with the bearing caps on.

Assembly lube was used.

Do you have a set of these brushes, or something similar?

https://www.summitracing.com/parts/mor-61820

Moroso Engine Cleaning Brush Sets 61820

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@nomorejohndeereWhen it spun the bearing it didn't eat into the journal, it just left a lot of bearing material stuck to the journal. all of it was machined off. all journals were then checked to ensure they were correct.

 

@Maynard I do and they were used.

 

@ksfarmdudeI can't remember what brand it was but I got it from a local dealer. Wasn't a cheap rebuild kit compared to the other kit they had.

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If the bearing is welding itself to the crank it is more likely a lack of lubrication than a bearing fit problem. As others have said if you can rig up an external oil feed to pressurise the system and see what oil flow you have. 
I’m assuming a new oil pump?  
a friend had several of thes tractors over the years. Most were neglected and abused. They all gave excellent service. One seized due to lack of oil changes. The oil was so thick it would hardly drain from the pan. Cleaned all the sludge out. New rod bearings (after he scraped the seized one from the crank). Reassembled and it just kept going. 
double check everything you have done and maybe get a fresh set of eyes to take a look in case you are missing something. 

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Make sure your oil holes match from main bearings to the block oil holes and that your oil holes in rod journals are drilled and open to the main journals. I heard of a guy that accidentally installed one set of main bearings in upside down (bottom bearing didn’t have an oil hole) and ruined the block and crank. Sounds like you have a lube problem to me.

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Maybe check the oil pump pickup screen/tube. If it has a crack and is sucking air, maybe the oil is become aerated and "foamy" reducing the effectiveness of the lubrication properties. 

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On 12/7/2022 at 10:20 PM, twinturboIH1566 said:

also it is not the same rod bearing each time, it is a random one. it seems the 2 piece bearing welds itself together and then welds itself to the crank.

 

 

just curious but what do the other 3 rod bearings look like after one of them spin

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Wow! Frustrating !!  You have done everything I would have done for sure  The fact that bearings are welding together definitely indicates lack of oil Random rods is a head scratcher though   It has to be in the feed from the block passages   Has the block been boiled out or are you doing this in frame

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@Red354I did this out of frame, the block was sent to a shop.

@hillmanThe new crank is actually new old stock, it did not come with the rebuild kit. The other 3 rod bearings looked fine when I removed them the 2nd time it spun a bearing.

@Farmall DoctorI disassembled and cleaned the oil pump everytime I pulled the engine apart.

@Hy1066I am using the correct oil, I wouldn't doubt a small amount of dirt would get into it during the rebuild, but if there was any dirt it was the smallest amount. I'd run the engine for an hour and then change the oil out and upon inspection of the oil it looked almost brand new.

 

I might give it one more try since bearings only cost me $100 and some of my time. I haven't disassembled it yet just dropped the pan to see if it was a rod bearing and it was. If it happened the same as it did the 2nd time I shouldn't need to send it to a shop to machine the crank since it doesn't gouge the journals out, just leaves bearing material stuck to it. 

Could long cranking time have anything to do with this? Even before it spun the bearing the first time it never fired up easy unless it was plugged in overnight. Even with the glow plugs you'd have to cycle them 4-5 times before it would start. I know these engines have a reputation for being stubborn to start, even when its 90* outside.

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Even when those engines are worn out, they will start well with good working glow plugs. Are you letting go of the glow plug switch while cranking, or do you continue the glow plugs until it starts? You should always continue to run the glow plugs until it starts. They cool off much faster than they heat up. 

    How did the engine sound when it was running? it should have a dull diesel "rattle". not a sharp hammering "ping".  have you ever checked injection timing? 

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