Yes Neil, in fact just this morning I spoke to a very clever guy here in Melbourne about possibly doing this, he said it will cost around $US150 per bearing, but the crankshaft needs to be in good condition. My crankshaft has old water stain damage unfortunately, and I'd really love to avoid having to dismantle the engine to clean up the crankshaft, it's already been ground to 30 thou under, this tractor will be lucky to do 5 hours a year.

It's a interesting problem Neil, when the engine oil is cold the oil pressure is a steady 34 pounds, both when slowly cranking the main over with the pilot motor, and when the diesel fires up, but within 20 minutes of starting the diesel, and the engine oil slowly warming up, I can see the oil pressure slowly decreasing on the guage, at high idle it's still 10-15 pounds, but at low idle it's only around 1-5 pounds, that's too low for my comfort.

I'm running 40W oil in the motor, and had the pressure relief valve screwed in as far as it will go, I dismantled the oil pump a week ago and it looks great, I can see how someone has been in there before and reconditioned it. I measured the conrod bearings on 2 cylinders with plastigage and got 13-14 thou wear, so they are at maximum wear, hence I thought if I could find some new bigend bearings I should help improve that low pressure at low idle.

I'm just confused at how I've got a beautiful 34 pounds when cranking the diesel motor over with the pilot motor when the oil is cold, then almost zero pressure when the oil is warm, unless the diesel is running above low idle. There is some minor wear on the oil pressure relief spring from rubbing within it's bore, and I'm aiming to replace that.
Thanks for your input, appreciate it
Mike

2F2360, or 5F2905, - 8B4320, 8B4321, - 5B1885, 5B1886, - 7B6929, 7B6930, - 5B3763.

I tell ya Josh, keep this up and I'll write to the Queen of England and ask her to knight ya, "Sir Josh" has a good ring to it I reckon.
Thanks for going above and beyond the call of duty.
Mike

I hope it leads somewhere, there may yet be more info, they made a lot of those engines for many different applications with minor variations and changes.

Yes, that is what I was thinking too Josh, I just couldn't believe there wasn't even one of those 2F2360 bearings in the world, even though Machinery Trader was saying there were plenty, Machinery Trader say Florin have 8 of the 5F2905 and I've emailed my buddy Dennis there to ask him to check, fingers crossed he can find them.

Thanks again Josh, I really do appreciate you going the extra yard to help, I'd be dead in the water otherwise.
Mike

Most of us don't realize how much the viscosity of oil changes with temperature. Here is a typical chart of 15W-40

wiki.anton-paar.com/en/engine-oil/

The change in viscosity coupled with generous clearances in the mains and rods makes for a great change in pressure from cold to hot. Changing the clearance of rods etc from .004 to .008 effectively doubles the size of the opening the oil pump sees and reduces pressure.

Rusting roads, good one Neil.

  That's nice to know Neil, there are times I over think things, and definitely times when I over repair my old dead Cats, for example replacing every bearing in a gearbox when I find one bearing not quite right, crazy really, and a waste of money realistically, because my old girls are lucky to get driven 5 hours a year on average, but I figure while I've got a gearbox apart, or final drive, or waterpump, the cost of the extra bearings is usually only $20-$200, and much easier to fit them at the same time and sleep easy at night.

This D4 7J is a bit different to my other "boat anchors", it has done around 40 hours solid work this past year since I replaced the cylinder liners and fitted new rings along with a reconditioned head, I wanted to bed in those new parts and so used it to pull my 9 tyne chisel plough, that plough is a good solid pull in 4th gear, perfect for bedding in new rings, and the tractor runs great and makes no odd noises.

Where I screwed up is I decided I wanted to know what the actual oil pressure was when the tractor was running, so I removed my NOS Cat oil pressure gauge made in 1962, that only has a red zone or a green zone on the face, and replaced it with a fancy oil pressure gauge that shows the pressure in actual pounds, big mistake, because previously that NOS red zone / green zone gauge was always in the green zone when the diesel motor was running, cold oil or hot oil, at low idle and high idle, but with the fancy pressure gauge I was seeing the actual oil pressure, and seeing it flickering at low idle between 0 and 5 pounds scared me.

You will have seen that old Cat Tech Sheet Eddie uploaded a few times over the years, from the 1960's, where Cat talk about the actual oil pressure of their engines and the "new" style red zone / green zone oil pressure gauges that replaced the older actual pressure indicating gauges. From memory Cat said the new gauges would register in the green zone at anything from 5 pounds pressure and above, and that 5 pounds was plenty for their engines.

I was talking to Eddie Bedwell about this recently and he reminded me that oil pressure gauges that show the actual pressure are really only accurate in their middle measuring range, they are not particularly accurate at the lower and higher ends of the dial, so maybe I should just refit my old bearings, along with my nice new 1962 NOS red zone / green zone oil gauge, fill the motor with some 50W oil and get on with my life if I can't find any undersize bearings.

D4Jim, thanks for that link, very interesting, I've always thought oil get's thinner as it heats up, that's why we change it when the engine is hot, but when I talk to people about 15W40, like I use in my Case tractor and Landcruiser truck, I get told the 15 is the "thickness" of the oil when it is cold, so it flows quickly around the engine when it's cold, and the 40 is the "thickness" when the oil is hot, but that seems the reverse to what I see, maybe you can explain it better.
Thanks
Mike

Aluminum?

Didn't Bill Glenn fabricate rod inserts from aluminum for the main engine in a Cat loader? If so it might work here.

Daron

      Good question daron, I can't remember that thread, but I'm sure it's possible, as they say "if man made it, man can fix it", though I'm sure nowadays we say women could fix it too! LOL

The bearings look just like those you find in a D2/D4 pony motor, which a Metallurgist told me years ago after he tested them, that Toyota Landcruiser alloy pistons were almost identical to, apparently they have a high % of tin in the aluminum alloy, like 2%, this guy said to get hold of a few old Landcruiser pistons, smash em up and melt them down to create new pony motor bearings, seemed to make sense to me at the time.

The first photo is the NOS oil red zone / green zone pressure gauge I use on my old Cats till we come up with something better, they were made in 1962 from memory and I bought them off a real nice guy Stateside on Fleabay, still in their original packaging, the size is perfect to fit the Cats, the other photo is the fancy oil pressure gauge I used to test the actual pressure, I also double checked that gauge with a old Stewart Warner gauge I have, and both gauges measured right around the same pressure.
Thanks
Mike