From the forum "REVIVING A RESTING UNIT"
"Under worst case the main engine may be frozen. Keep in mind here that frozen engines are seldom returned to normal operation. Even if it is possible to get the pistons moving there is most likely unseen damage to the rings. Only the lightest of sticking from varnished bores are recoverable. Un-freezing the engine should be achieved for convenience of dismantling for overhaul. There are many techniques used to get pistons moving and sleeves pushed out of their bores."
What is the downside to starting an engine that was stuck? Is it likely that further costly damage will be done? I assume some cylinder wall damage could be seen upon inspection, possible valve and seat damage from moisture as well. Why not remove the fuel injectors, give each cylinder some lubrication and work the engine by hand cranking until it feels smooth?
The subject tractor is a D6B, SN 44A 500. Can someone tell me the engine used in this tractor so I can try to hunt down information without buying the tractor's shop manual from Caterpillar? My Case IH dealer's shop foreman thought perhaps it could be a 3306, but looking at his book and comparing some fuel injector information to information in my parts book seems to indicate otherwise.
Thanks for any help you can give me!

Your D6b 44A has the D333 6 cylinder engine with a 4.5" bore. Note there was a C version of those engines that came a few years later, immediately proceeding the 3306. Those 4.75" bore engines were more similar than either one was to the original D333.

There is nothing lost in attempting to get a stuck engine loose and little downside to getting one running. It is rare that there is damage to the crankshaft, bearings and oil pump because any water that collects in the oil pan will float the oil up, usually submerging the crankshaft in oil. As long as this is removed before startup and oil changes performed to clean up the residual moisture and sludge, those components are almost always fine.

Above all else every effort should be made to prevent damage to the crankshaft. The crank, cylinder block with its associated components and head are the major parts of the engine, the rest is easily and cheaply replaceable. Luckily, the bottom end usually fares much better than the cylinders and rings and damage to other components other than valves and seats is also unlikely.

You may get lucky and have a runner in the end. I would say in general, if you have to take the head off to unstick one, it is unlikely to end up as a runner, just because of the tendency to say " well I am this far into it, might as well go ahead and replace xxxx while I am here"

Welcome. I believe your D6B has a d333 engine, the for runner to the 3306.

As far as running a stuck engine, you certainly could get lucky and be fine, but I know if I tried it something would fail catastrophically. I suppose it depends on how badly it was stuck. At the very least take the valve cover off and check for stuck valves and see how much crud is sitting on the overheads.

Another thing that’s helpful is to edit your profile and include your location, could be there is another member close by that could help. A D6B is a wonderful tractor, good luck with yours!!

Bruce P.

Thank you, ccjersey and Bruce P. Once I learn what is required to re-install the fuel injectors, I will give it a try, taking the precautions suggested. The 3306 service manual indicates only a torque specification, but the parts book I have for the D6B calls for seals. Any suggestions on lubrication for the top end?

my advice:
take injectors out, put in every cilinder a mix of brake oil and kerosene, let i it sit for a month or more,
then after a month or more : put in the watersystem hot water (from steam cleaner for excample)
put long bar on crankshaft, and try to move it back and forward bit by bit til you can go al the way around,
then its your decision, but i would recomend taking head off , oil pan off and pisons out, cilinderlinings out if they are the wet type is the best (but not neccecary.)
in every cilinder the honing tool,
see how pistons and rings are, or better put new ones, check free play of piston pins. of not good put new pins in.
clean oil pan inside,
test injectors,
check cil head/valves ,clean/ polish valves
new seals,
put all back ,
new head gasket and as most of all gaskets/seal new.
refurbish waterpump,
new v belt,
and then your good to go

The brake fluid recommended is if there is water (in my opinion). If no water in the cylinders, then I would stick to petroleum products. One of the most effective (and cheap in large quantities) solvent concoctions you can find is a mixture of 1/2 acetone and 1/2 automatic transmission fluid. Costs about $5 a quart.

The seals your book mentions are just dust/dirt seals and are not required to run the engine. I would try to find them from an aftermarket source if possible. I went by my nearest CAT dealer a while back while I was in the city for other business. Figured I would save waiting on those seals being shipped in from another source. Not only did they not have enough of either one to do a 4 cylinder engine, when I went to pay for the ones they had, I was darned glad they only had a few! Needless to say i didn't have them order the rest of them in.

Remove the injectors, keeping them clean and in order so you know where they came from for diagnostic purposes and then you have ready (though small bore) access to the cylinders to put in whatever you want. If you want bigger access you can drain the cooling system and remove the precombustion chambers. This will leave about a 1" opening that you could suction out liquids etc. You will absolutely need to replace the precombustion chamber seals both top and bottom. The bottom PC chamber copper washer seals can be reused if necessay by heating to a dull red and dropping into water to anneal them. However, you may need to put each one back in the original hole so the glow plugs align properly and do not interfere with the injector lines. It takes a special splined tool to remove the PC chambers.

Thanks again to all of you. I have a couple more questions, but will need to get back later with a photo to clarify.

I was able to start the engine today, after several hours of effort over a few days. Would like to post video of it running, but haven't figured out how to do that.
Now I have the stuck steering clutch to deal with. I suppose that will require removal and disassembly. Any suggestions to try first?
Thanks for your help so far, and for any new suggestions.

That’s great!! Looks like a farm cat with a ccu on the back? Or is it a bee Gee hydraulic unit? At any rate if you can hook it up to something that will load it good ( like that scraper) you might get lucky and get the clutch to release. I’ve heard of driving around with the brake applied slightly to make some heat helps.

Are you by chance located in the PNW??

Good luck

BP.