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spun bearing multiple times, help appreciated


twinturboIH1566

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1 hour ago, twinturboIH1566 said:

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.

Isn't there a term for doing the same thing & expecting a different result??  Ahem....

I would think long crank times would be BETTER - since the long crank cycle allows the engine to build oil pressure before it starts spinning fast while running.   The same idea as the standard practice of unplugging the coil or shutting off the fuel and spinning the engine over multiple cycles to get the oil back into everything on a new rebuild or a engine sitting for a long time.   Which makes me think - have you watched oil pressure while cranking/running?

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Thinking some more Before you throw another 100 into bearings I would shoot some pressured air into the crank journals for the rods I would think if air pressure is seen blowing out on other bearings it should be clear If the hole in the upper bearing is aligned You should be good

I don't know if you have an electrical or mechanical oil gauge but I would definitely stick a mechanical one to where your at

 

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@Red354The main bearings look almost brand new. I also have a mechanical gauge.

@Jeff-C-IL I don't intend on just throwing new bearings in it and firing it up, if I do anything I'm going to look at everything with a fine tooth comb.

@Farmall Doctor I tested the glow plugs on the first rebuild and they work as they should. The engine definitely sounds the way an old diesel should sound, I haven't messed with timing or the pump at all since I've had the tractor.

 

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Like England 806 says... pressurize oil from another source, and watch it with the pan off. After what you went through, I would be afraid to start it unless I saw oil pouring out of the connecting rods with my own eyes.

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If nothing else build or borrow ( or buy) a preluber to make sure the bearings have oil immediately. I think I would prelube it and then take the caps off and make sure each bearing is getting oil

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Lots of good information here but it's difficult to diagnose these things from a distance. I would recommend you have someone else who is experienced in engine rebuilding look at it for you. Sometimes a different set of eyes is very helpful.

Pics would help us help you.

I would throughly examine the complete lubrication system of the entire engine, the crankshaft and the rods.

Which tractor engine family is this, I'm not familiar to the 434?

Thx-Ace 

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6 hours ago, Farmall Doctor said:

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. 

 

our neighbor had a B250  that was never rebuilt, we used it to haul wagons filling silo back in the 80s but had to stop using it because it smoked so much we couldn't tolerate the smoke while unloading (under slung exhaust|). It started reasonably well

48 minutes ago, acem said:

Lots of good information here but it's difficult to diagnose these things from a distance. I would recommend you have someone else who is experienced in engine rebuilding look at it for you. Sometimes a different set of eyes is very helpful.

Pics would help us help you.

I would throughly examine the complete lubrication system of the entire engine, the crankshaft and the rods.

Which tractor engine family is this, I'm not familiar to the 434?

Thx-Ace 

its a British BD154 like a B414,424,444 ......,and same family as B250 ,B275 etc very good little engines . 

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4 hours ago, twinturboIH1566 said:

@Red354The main bearings look almost brand new. I also have a mechanical gauge.

@Jeff-C-IL I don't intend on just throwing new bearings in it and firing it up, if I do anything I'm going to look at everything with a fine tooth comb.

@Farmall Doctor I tested the glow plugs on the first rebuild and they work as they should. The engine definitely sounds the way an old diesel should sound, I haven't messed with timing or the pump at all since I've had the tractor.

 

have you changed the rod bolts?

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@hillmanYes all brand new con rod bolts. This 434 also had the exhaust running under it and I couldn't stand it when sitting still or reversing, flipped the manifold and that problem was solved.

@Nebraska1206Lucas assembly lube the first time, then I used permatex assembly lube the second time since I couldn't find lucas at the store.

 

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The only real oil pressure issue I ever had was with a 706 gas.

It had been overhauled twice when I first met it.

It ran very low oil pressure.

This engine would eat oil pumps and the gears off the cam.

I found the 706 went to the newer aluminum oil filter base.

That included the oil pressure relief valve and the bypass valve in case the oil filter plugged.

We found the factory had installed the old style cast iron 560 type oil filter base gasket in the newer 706 aluminum base.

This mostly plugged the oil pressure coming from the oil pump to the filter base.

This oil pressure was unregulated and this caused the worn oil pumps and cams.

It was building high pressure with no place for it to go.

We replaced the gasket with the right one and oil pressure came back up to normal and it ran as it should.

It appears you are doing all the proper steps with this overhaul but there is something being missed.

Sometimes you need to set down, by yourself, and look at each and every part, gasket and piece.

Make sure it makes sense in your mind before moving onto the next piece.

It sounds like the rods are on the far end of oil pressure. 

I would spend a lot of time looking over the oil pump, oil filter and everything having to do with lube. 

If not hot tanked and all oil passages cleaned with bore brushes, it should be done.

Spinning a rod bearing happens but it is not normal.

Think back to when it originally spun the bearing the first time.

Do you know why that happened?

 

 

 

 

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On 12/9/2022 at 1:03 PM, twinturboIH1566 said:

 

Gaskets....  

Dad bought a '78 Old Diesel Delta 88.   Everybody says those engines were terrible - but we had problems with the TH200 transmission instead.   It just would not shift correctly once it warmed up - and if it missed, you had to shut down and restart.   The first 2 years we had the car, it spent more time at the dealers then on the road.   I know dad had that car in at least 10-12 times, always "Oh its fixed now".....nope.    Finally gave up and just drove it and dealt.   120K miles later and  demoted to a "extra" to jump in if the newer cars broke - sometime mid 90's - I needed a car, pulled it out and decided to change tranny fluid.  Dropped the pan, looked at the valve body "You know, I'm curious" .... I pulled the entire valve assembly off, looked it over - "Hmmm, what are these markings on the gaskets?  One says VB, one says C....lets see, that would be Case and Valve Body.  So why is the one marked VB against the case and vice versa?"   I literally switched the gaskets, put it back together.....and it worked perfect!   Drove the car another 20K with no further issues!    It apparently came from the factory new that way - and the dealer "service" guys never even looked.....😒

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im like diesel doc, thinking the first time it spun bearing before engine overhaul,  something came loose , something broke and got something plugged, or something wore out,or something  cracked. im thinking oil pump , gasket backwards covering a hole ,or   .just think of the satisfaction you will have when you find the problem.imo

 

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I just kind of skimmed the 1st and last pages of this thread, and it's probably already been brought up, but - rod caps are one-way-only.  You said something about the shell halves welding themselves together - that sounds like a backwards cap to me?

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@DT361 The number on the rod bearing caps face the cam, I made sure to put them in the right way.

@Diesel DoctorWhen it spun the first bearing I had started it to go and bush hog a field, went inside the barn to grab some headphones to listen to music, came back out and as soon as I sat down on the seat is started knocking and making a squeal. It still had good oil pressure, so I shut it off and trailered it to the shop. Drove it off the trailer and into the shop, as far as I remember it never actually locked up.

My guess is I had overworked it the week before when mowing a steep hill. Noticed the water temp was in the red and got to the top and just let it sit at 1000 rpms till it cooled down a few minutes later. Ran it for several more hours without a problem.

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  I never saw that you checked the rod journal bore in the rods. They can become odd shaped. Although it was running before the rods and old bearings changed gradually over time. Likely ran hot several times. When you put new bearings in it is possible to have insufficient clearance in an area.

  Put new rod bearings in an engine once and in locked down during assembly. Rods were badly out of round. 

  Have seen many engines ran extremely hot. They are more inclined to have head gasket, head and piston problems than bearings. Running hot is not good but doubt that caused the spun bearing.

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