31 - Engine Disassembly, pt. 1

With the head back from the machine shop after inspection, I reckoned I'd best get down to pulling apart the block. 

I've *obviously* never taken apart and rebuilt an engine before. But hey, we live in a time where there is a youtube video for everything and, where there isn't, a helpful AI-bot (please don't kill us all) will be around to answer dumb questions. How hard can it be? 

Let's start small by taking off something simple. Like the fuel lift pump:

Easy! And, most refreshingly, it's all metric! How civilized -- particularly after all the gearbox stripdowns I've done, which involved three different types of fasteners.

Fun note: Present me has no idea why the two bolts, here, are differently-sized as you can see in the picture above. And to be honest, at the time I didn't even notice. (Future me, the one writing this blog post, has a much better idea of what's happened.)

The first sign of trouble in this process came when, after I removed the two cover plates on the oil filter housing side of the block, I found some metal chunks. Uh oh.

Hmm. Those aren't supposed to be there. 

Well, carry on I suppose. Let's take off the oil filter housing too, since we're on that side of the block:

Seems like... some kinda silicone, maybe, someone put here at this plug on the top of the filter housing? Is there supposed to be a copper washer or something in here to stop the filter housing from leaking? Whatever it should be, the silicone didn't work, as you can see from the condition of the housing. 

Here's the oil pressure regulator thingy. Looks clean enough and seems to function okay. Things are going well. I have everything off the passenger side of the block stripped off and bagged for inspection.

Time now to pull the guides, rollers, and followers out of the top of the block:

They all look pretty good, actually. No significant wear that I could tell, though some of them were in backwards. The followers (lifters? whatever the correct term is), the brass pieces above, are directional. That is, they're marked so that one side of the part is supposed to face forward. At least three of mine were in backwards. Hmm. Glad to see the engine was properly rebuilt in the past.

At least I don't think I'll have to replace these parts. They look fine. I'll just reassemble them correctly when I get to that point, even though they'll technically be 'backward' to their last operating state. Each of the three-part assembly (four including the guide retaining screws) was cleaned in the ultrasonic cleaner, lightly oiled, and put into a separate ziploc baggie and labelled for reassembly. 

Now on to a task I've been dreading for a couple of reasons: getting the front crank bolt off. 

Step one, removing the oil pan:

Is there ever a time when this isn't totally gross? I mean, gawd, they all leak, don't they? So every time you do this, there'll be a godawful mess of oily dirt to scrape off and remove. 

Some fasteners were so full of gunk I had to scrape off the bolt heads to get a socket on them. 🤮 Eventually, of course, they all relented, and the oil pan came off fairly easily. All things considered, while it's a messy job, it's not a tough one.

... so on to the tough one!

In order to remove the crank bolt, which is torqued to infinity, you need to find some way of stopping the crankshaft from spinning. The method I assumed would be most useful is to wedge a piece of wood in the crankcase through the opening in the ladder frame, and hope nothing breaks when applying torque to the nut. So that's what I did. 

You can see in the picture above that there are a couple of problems. 

First problem, the pulley is not straight. Someone has hit it back on again with a hammer and weeble-wobbled the pulley -- the sides of each belt groove are not smooth. Sigh.

Secondly, and this gets to one of my reasons for dread, is that the last time this was done, someone who thought they were clever welded (yes, welded!) the crank bolt inside of a Series truck-style starting handle dog. How he or she felt they'd be able to crank start this diesel engine by hand is a mystery to me. 

But here we are. The challenge is that there's no way to get a socket on that bolt -- it's tack welded in two places. No socket means no way to use an impact gun or get a breaker bar on the bolt.

So, what I did was take my household wrecking bar and applied it to the slots in the handle dog as a lever. You know, it's one of those nail puller-things with a 90-degree bend in it for doing household demo work. Probably about 16" long. I had no idea if it'd be strong enough for the job, because I wasn't sure how hard I'd have to lean on the thing to get it to turn. But it had to work, so away I went. 

To my surprise, the crank pulley bolt was barely hand-tight. Off it came.

You can clearly see the homebrew job that someone did on this thing. Couplea gobs of weld, and hey presto!

Of course in the process of doing this the previous 'owner' (it's clear this engine was stolen) made some questionable decisions. With the slotted part in place, the number of threads going into the crankshaft from the crank pulley bolt were decreased by a quarter-inch or so already, thanks just to the thickness of the slotted part. But in addition to that, someone appears to have cut the end of the bolt off. Probably not a standard bolt?

Anyway, you can see from the state of the threads above that only three or four threads' worth were making contact with the crankshaft -- and the bolt was not much more than hand-tight.

Yikes.