My set is over 50 years old.
You most likely never need them again the newer motors use different tools.
If the machine shop has been around awhile they should have a set as the precups come out to work on the head.
Bad Bob
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Caterpillar 12 grader engine is dead - please help?
- Thread starter Entropy1
- Start date
You most likely never need them again the newer motors use different tools.
If the machine shop has been around awhile they should have a set as the precups come out to work on the head.
Bad Bob
Entropy1
Well-Known Member
Forgive me for speculating again (my grader service manual hasn't arrived yet - I might have to reorder it)
Presumably there's an inner transmission shaft that's direct-coupled to the crankshaft (no clutch, always turning) - which powers the machine accessories. And there's an outer transmission shaft that's clutch-coupled - for driving the wheels. There's a clutch brake - presumably to stop the clutch-disk for shifting gears (no syncros within the transmission?) There's also a mystery bellhousing bolt pattern - presumably CAT unique, and not SAE (no one seems to know). Then there's also the direction of crankshaft rotation, which I assume to be clockwise (looking at the water-pump end of the crank (direction also supported by the left-hand threads on the crankshaft pulley bolt).
I would need to find a replacement engine making comparable horsepower and torque, with lots of rotating inertia - perhaps a Cummins NHC-250 would work well? The easiest path forward would be to adapt the stock D318 clutch & flywheel to the cummin's crankshaft. Then either modify the cummins bellhousing, or adapt the CAT bellhousing to the cummins, or simply fabricate a new bellhousing - to join the cummins with the CAT 12 transmission - while maintaining the proper geometry & spacing of the stock components. Seems pretty straight forward.
Note: I enjoy a challenge. If I wanted easy, I would've purchased a newer grader that runs well. Currently I desire to rebuild the existing D318. But I must admit - the more I'm told that an engine swap cannot be done, the more I desire to do an engine swap.
Presumably there's an inner transmission shaft that's direct-coupled to the crankshaft (no clutch, always turning) - which powers the machine accessories. And there's an outer transmission shaft that's clutch-coupled - for driving the wheels. There's a clutch brake - presumably to stop the clutch-disk for shifting gears (no syncros within the transmission?) There's also a mystery bellhousing bolt pattern - presumably CAT unique, and not SAE (no one seems to know). Then there's also the direction of crankshaft rotation, which I assume to be clockwise (looking at the water-pump end of the crank (direction also supported by the left-hand threads on the crankshaft pulley bolt).
I would need to find a replacement engine making comparable horsepower and torque, with lots of rotating inertia - perhaps a Cummins NHC-250 would work well? The easiest path forward would be to adapt the stock D318 clutch & flywheel to the cummin's crankshaft. Then either modify the cummins bellhousing, or adapt the CAT bellhousing to the cummins, or simply fabricate a new bellhousing - to join the cummins with the CAT 12 transmission - while maintaining the proper geometry & spacing of the stock components. Seems pretty straight forward.
Note: I enjoy a challenge. If I wanted easy, I would've purchased a newer grader that runs well. Currently I desire to rebuild the existing D318. But I must admit - the more I'm told that an engine swap cannot be done, the more I desire to do an engine swap.
Birken Vogt
Charter Member
Here is a dozer D318 that might be available:
Entropy1
Well-Known Member
If I do attempt to repower, one of two things will happen.
(1) I'll post pictures & videos of the grader running with a different engine
(2) I'll have to eat some humble pie and report that I failed
If the cylinders got exposed to water & deep-freeze (was parked in eastern Washington) the block may be freeze-cracked beyond use. I'll know more when I get the engine pulled & disassembled. I am not going to spend 6 to 9 grand to obtain a running D318 engine. Honestly I'm not too happy about spending 4 grand rebuilding the one I have.
I would however be quite willing to spend a few weeks of my time, together with some thick steel plate that I already have - to machine the required adapters for swapping in a used truck engine.
(1) I'll post pictures & videos of the grader running with a different engine
(2) I'll have to eat some humble pie and report that I failed
If the cylinders got exposed to water & deep-freeze (was parked in eastern Washington) the block may be freeze-cracked beyond use. I'll know more when I get the engine pulled & disassembled. I am not going to spend 6 to 9 grand to obtain a running D318 engine. Honestly I'm not too happy about spending 4 grand rebuilding the one I have.
I would however be quite willing to spend a few weeks of my time, together with some thick steel plate that I already have - to machine the required adapters for swapping in a used truck engine.
Tugger2
Senior Member
Im sure you can find a running D318 for a lot less then 6k.I bought a good runner a few years ago for 800.00$ . Im sure you can make another engine work somehow ,but it just seems sacrilegious to ruin a nice old machine like that with an odd power plant. I saw a D4 for sale a while with a small block V8 in it , piece of scrap in my opinion.
Entropy1
Well-Known Member
I would happily spend 1500 on a running D318 engine. Unfortunately it's unlikely to happen in my part of the woods. We had a steel bubble several years back, and our three largest wrecking yards cashed in (aka scrapped every car, truck, and bus on their lot). It's quite depressing. They had rows of old Pontiacs, Olds, Caddys - all gone. Now the oldest cars are 80s POS.
During this same steel bubble people were scrapping running dozers, graders, loaders, excavators, etc. It was shocking to watch. Granted they were older machines, but they were literally worth more in scrap than as a running machine via private sale.
Due to the steel bubble, and other factors - there's not a lot of running D318s left to be had. . . . Don't get me wrong - I'm actively looking. The few I've found come with an entire machine, and cost 6 to 9 grand, or more $$$.
During this same steel bubble people were scrapping running dozers, graders, loaders, excavators, etc. It was shocking to watch. Granted they were older machines, but they were literally worth more in scrap than as a running machine via private sale.
Due to the steel bubble, and other factors - there's not a lot of running D318s left to be had. . . . Don't get me wrong - I'm actively looking. The few I've found come with an entire machine, and cost 6 to 9 grand, or more $$$.
Birken Vogt
Charter Member
Did you contact that guy on Youtube I posted earlier? No idea if it is still there or for sale but appears to be in your neck of the woods from the background scenery.
Entropy1
Well-Known Member
His video was posted 5 years ago. He states he plans on using the engine in a sawmill someday. Assuming he still has the engine, I am going to go out on a limb and speculate that I'm not taking possession of his engine for 800, or even 1500 dollars. More specifically, someone that takes the time to post videos of an engine that he's salvaged is probably not interested in selling it (at least not for the prices I'm looking to pay). Again, that's speculation on my part - but probably pretty accurate assumptions.
Did I contact him? No. Honestly I'm not sure how to even contact the originator of a youtube video.
Each spring about 3 (on average) road graders are scrapped at our local recycler. If I see a CAT 12 show up with a D318 that bars-over, you can bet that I'll be purchasing it. . . .
Did I contact him? No. Honestly I'm not sure how to even contact the originator of a youtube video.
Each spring about 3 (on average) road graders are scrapped at our local recycler. If I see a CAT 12 show up with a D318 that bars-over, you can bet that I'll be purchasing it. . . .
skyking1
Senior Member
so you oiled the heck out of it and let it sit a week?
Entropy1
Well-Known Member
I am trying to acquire the proper CAT tool kit to extract the precombustion chambers so I can borescope the cylinders. I found the extraction bolt for removing the precombustion chamber (purchased it), however I do not have the rest of the tool kit - for removing & installing the precombustion chamber retainer. I might be able to screw the whole assembly out at once with the extraction bolt I purchased, but that's not the procedure called out in the service manual. The retainer is supposed to be pulled separately. If I try to pull both at once, I might strip or shear the bolt. Even if I successfully extracted the chamber & retainer, I'd need the complete tool kit for proper reinstallation. I must admit, it's discouraging that CAT service tooling is hard to find. I suppose I could take measurements & fabricate my own tooling, but I'd much rather purchase the proper tool set. The extraction bolt I purchased appears heat-treated - presumably a chrome-moly alloy.
I still desire to see inside the cylinders - before I wrench on the crankshaft with maximum effort. It's currently not turning with a few hundred foot-pounds. The large nut on the end of the crankshaft is accessible with a wrench, however to place a large socket on the nut (for applying significant torque) requires me to pull the radiator assembly - to get clearance for the socket. I'm waiting on nicer weather. It's been snowing all weekend.
I still desire to see inside the cylinders - before I wrench on the crankshaft with maximum effort. It's currently not turning with a few hundred foot-pounds. The large nut on the end of the crankshaft is accessible with a wrench, however to place a large socket on the nut (for applying significant torque) requires me to pull the radiator assembly - to get clearance for the socket. I'm waiting on nicer weather. It's been snowing all weekend.
skyking1
Senior Member
So you did oil it?
Entropy1
Well-Known Member
Not oiled yet. I still want to see the current as-is status inside the cylinders. My borescope cannot get past the precombustion chambers to inspect the cylinder walls. This is why I'm trying to purchase the precombustion chamber tool kit. Once the cylinders are filled with oil, pictures probably won't show much (I don't think the camera will image well under oil).
I did try to turn the motor nonetheless. I only wrenched on the crankshaft hard enough to turnover an unstuck engine - verifying that it's in fact stuck. But stuck how badly is still TBD.
My current plan:
(1) Pull the precombustion chambers and borescope the cylinder walls & assess the damage. Specifically, I'm hoping to see whether or not the water damage is severe, or mild.
(2) if mild, pull the radiator so I can get a large socket onto the crankshaft nut
(3) soak cylinders in mix of trans fluid and diesel
(4) attempt to bar over engine with appreciable torque input
On that note - the guy who delivered the machine recommended that I place the grader into high gear and push it with my excavator - aka try to use the grader wheels to turn the engine through the transmission. I'm not sure whether or not this is a good idea. I'm assuming the wheels would slip before I break something. Again, this is why I want to borescope first. Once I took apart a Detroit 671 that sat with water in the cylinders. It took a hydraulic press to dislodge the pistons from the cylinders. I probably would've broken the crankshaft before those pistons moved - or possibly sheared the main caps - if it's even possible to apply that much torque.
In a way, it's a blessing to have removable sleeves. If the water froze however, all bets are off. I'm not even attempting to rebuild a freeze cracked engine. If the cylinders contain heavy visible corrosion, I'm not even going to bother trying to soak the cylinders and break it loose. I'll pull the engine and disassemble it for inspection.
I did try to turn the motor nonetheless. I only wrenched on the crankshaft hard enough to turnover an unstuck engine - verifying that it's in fact stuck. But stuck how badly is still TBD.
My current plan:
(1) Pull the precombustion chambers and borescope the cylinder walls & assess the damage. Specifically, I'm hoping to see whether or not the water damage is severe, or mild.
(2) if mild, pull the radiator so I can get a large socket onto the crankshaft nut
(3) soak cylinders in mix of trans fluid and diesel
(4) attempt to bar over engine with appreciable torque input
On that note - the guy who delivered the machine recommended that I place the grader into high gear and push it with my excavator - aka try to use the grader wheels to turn the engine through the transmission. I'm not sure whether or not this is a good idea. I'm assuming the wheels would slip before I break something. Again, this is why I want to borescope first. Once I took apart a Detroit 671 that sat with water in the cylinders. It took a hydraulic press to dislodge the pistons from the cylinders. I probably would've broken the crankshaft before those pistons moved - or possibly sheared the main caps - if it's even possible to apply that much torque.
In a way, it's a blessing to have removable sleeves. If the water froze however, all bets are off. I'm not even attempting to rebuild a freeze cracked engine. If the cylinders contain heavy visible corrosion, I'm not even going to bother trying to soak the cylinders and break it loose. I'll pull the engine and disassemble it for inspection.
Birken Vogt
Charter Member
He stated in the comments 1 year ago that he did not use it for the sawmill project and used a Perkins instead. That is why I think he might still have it. All he could do is tell you know. There is probably some way to send him email or just post a comment to start.
Entropy1
Well-Known Member
Maybe I need to create a youtube account - and I'll be able to message him? I'll look into it. . .
BSAA65LB
Senior Member
IME, 50%ATF/50% Acetone works well at getting stuck piston freed from rusted cylinders.
Then you can post videos of your progress. I'll subscribe.
TomA
Well-Known Member
The best way to apply torque to turn a Cat engine is to put the pony in gear and turn the pony flywheel. The problem is the lock needs to be removed to put a socket on the pony flywheel. To reverse direction the nut might back off. If it moves at all maybe gentle back and forth movement could work, that nut is usually very tight and hard to break free.
All you really need to remove pre cup is the spline tool. I don't know if that is what you have or not. That will require a lot of force, cheater bar.
All you really need to remove pre cup is the spline tool. I don't know if that is what you have or not. That will require a lot of force, cheater bar.
Birken Vogt
Charter Member
If you have a gmail account, that is your youtube account also I think.
Did you say the intake or exhaust manifold had been removed? take one of those off and see if you can get the borescope by the valve. Even the exhaust manifold will show how rusty the cylinders are likely to be. Then you can determine which cylinders are in the middle of the stroke, and apply hydraulic pressure to that pair, with a tractor hydraulic remote or other source.