Traxcavator 12A04040 1958, Started troubleshooting and had a time getting access to turn over the diesel. Pony would turn over by hand but the diesel would not. Front mount Hyd pump no access to crank pulley. Turns out pinion (after many hours of troubleshooting and a few expletives) the clutch was way too lose and would slip AND gear and pinion sleeve are locked and in the engaged position. The Pony engine is off an earlier Dx 3400. On the D315 the diesel engine the intake had been blocked off where the exhaust enters the intake; also the coolant flows out of the right side of the head on the D311 to the pony was deadheaded. The older 3400 used a hole on the back of the head where the coolant exchange through the head and pony - it too was blocked off. There was no circulation between diesel and pony. Bad Ju Ju...
Oils looks old but good (darkish honey) so far haven't dove into the filters yet.
Fuel looks and smells old and fuel filters had some fines but cleanish - still needs changed
Then I pulled the exhaust manifold suddenly I heard bagpipes starting to play "Ol' Danny Boy"!

Hi Dan,
crud in oil settles by the effects of gravity over time and so will settle on the bottom of the compartment, engine oil pan, etc. so be AWARE that the crud is waiting to be ingested by the oil pump and be pumped thru your engine etc.
If enough crud is present it can block the oil filters or even with cold oil the filter by pass valve can open and let unfiltered oil thru to the system with a bad outcome.

Loosen the compartment drain plugs about half way or so out and see if oil or water comes out past the threads--if no oil or water then a lot of crud will be stopping the oil/water flow--check further.

Sadly it looks like water has got down the exhaust--maybe pull the inlet manifold too to see if a cylinder was on T.D.C. at valve overlap--both valves open-- and let water across to the inlet side too.
Pull the injectors and see if rust appears there too on the injector tips.

Likely best to just bite the bullet and pull the Cyl. head as it is possible that the valve stems are rust pitted and if so you run the likelihood of dropping a valve head.

The pony pinion can be disengaged by finding a small 2 bolt cover on the top left of the Mains clutch housing cover.
You can access the pinion and so look for the two dogs--may be hard as you cannot turn your main--by turning the pony flywheel until one aligns the opening, and push hard with a bumping action on the rear most end of the dogs where the unlatch adjusting screws are--have a split pin to hold them--to release the dogs--they are geared together and so work as one--pinion should release and fly back with some spring force--be careful.

Finally working from blank laptop here after mega melt down of old one--no pics on this one yet--hope to load pix from old clunker in due course.
Need help to download old files.

Cheers,
Eddie B.

Thanks : Eddie B.
I have no delusion of grandeur here (ha ha:smile:) it is a 1958 Cat, I am having fun, yeah this thing has set for a few years and I am expecting to see quite a bit of crud at the bottom. I have already came across some gack in the bottom of the pinion clutch. Though, I've seen settled out old carboned diesel engine oil look like black molasses on the stick also. As soon as I can I'm cutting into the engine and hyd oil filters. But for now I'm still chasing this rabbit down this rabbit hole. I decided to pull the cylinder head so that's where I'm headed now.

Great Idea about compartment drain plugs ... cool trick

Yeah I pulled the intake and all four cylinders were dry and so that's when I decided to pull the head. I did pull the injector lines and No. 1 and 4 cyl(s) were wet (diesel) but No. 2 and 3 were dry and had surface type rust where lines connect to injectors ... lines were clear. I will check the the injector tips after I pull the head ... might be better to pull injectors while the head is still connected.
Another good trick to know "--maybe pull the inlet manifold too to see if a cylinder was on T.D.C. at valve overlap--both valves open-- and let water across to the inlet side too." - Thanks


The pony pinion problems complicated troubleshooting: one thing was where the gear sleeve was stuck in the engaged position. The pinion clutches were so loose they would not hold and needed adjusted.

I'm making YouTube videos on the rebuilds All I have posted so far is them coming home

Thanks for the info

Cheers, back at ya
Fat Dan

Hi Dan,
be aware that with the head removed and now if you turn the engine the liners are now only held in the block by the O Ring seals at the base of each liner--in an older unit rust and crud also makes 'em stick in place and can then fall into the oil pan-- the liners can come up with a rising piston.
In a engine being rebuilt ring friction can unset them too and let crud under the liner flange into the block seat area and allow water leakage or worse still, a cracked liner flange or counter bore seat in the block if the liner is then clamped down tightly onto the seat--

You need to put at least 2 suitable sized washers per liner--can overlap 2 liners with one washer--with a piece of insertion rubber sheet or similar under said washers to protect the liner upper gasket faces, on the head studs to hold the liners in place--about 25 lbs/ft torque or less is usually sufficient.

Cheers,
Eddie B.