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Tractor Damager
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Discussion Starter · #41 ·
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...like I said, you get good access to the crankshaft etc. with the balancer gears out of the way.

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Here's the crankshaft shell-bearing - to my untrained eye, it looks pretty scored and worn, but I'd very much welcome the views of wiser heads, here.

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Next thing out is the oil-pump. Removing this turned out to be a barrel of laughs, as both studs came out of the block rather than the securing nuts coming off, so there was a far bit of juggling the oil-pump to get it out with both shafts still in it! The shell here doesn't look as bad, but there's a bit of a scratch in it where presumably something hard and nasty has got stuck in there at some point...

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So there you go, full access to the crankshaft and con-rod cap bolts.

I've loosened off all the cap bolts and removed them from the front con-rod, but the cap is absolutely stuck to the rest of the con-rod. I've tried hitting it with a rubber mallet, "tapping" it with a lump-hammer and even carefully trying to wedge a screwdriver into the join out of desperation, but it just won't shift. Any guidance or experience here would be very welcome!

The next plan (assuming I can get the con-rod caps off!) is to remove the pistons and see which one's missing a ring and what damage that did on its way out...

On a separate note, I filled the block water-jacket with coolant (and used red coolant so I can differentiate it from the blue that was already in it) a fortnight ago, now, and none has apparently leaked out past the liners, so I'm feeling more confident that the liner seals haven't failed...

Thanks for any advice and suggestion,
Cheerio :)
 

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Some times a good solid rap with a dead blow hammer to each side and the they will separate,
or possible a clean wooden dowel set down on the piston and a sharp hammer rap.
 

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Tractor Damager
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Discussion Starter · #43 ·
Thanks very much for your advice (y)
I gave the end-cap a good old battering, but it wouldn't shift...in the end, I had to resort to jamming a screwdriver into the join:

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Finally off - there are short inserts which mate the cap to the rest of the con-rod, which have formed a sort of pressed joint...very tricky to separate!

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I then realised that I could feed a metal rod in through the tractor frame, put the end against each cap and use it as a long drift, making removing the rest much easier. I'm using freezer bags to keep all the parts organised...

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With the caps off, I could now push the pistons up through the block. To give a bit of control, I set up a bottle-jack with a piece of wood pushing against the end of the con-rod and another to brace it against the inside of the block (to stop it going sideways). Each piston was then fairly easily pushed up and withdrawn.

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The pistons themselves all look fairly similar - there's wear on the sides, which I'd welcome the knowledgeable to comment on.

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The front piston has a snapped top ring, but all the pistons had intact oil rings...one of the con-rod shells came loose when I removed the end cap and I noticed it wasn't a BMC or Leyland part, so presumably somebody's had this engine apart before and carried out a similar rebuild. I can only assume an oil ring snapped in the distant past and part of it was left in the sump...

All of the bearing shells are worn and/or pitted, so I'll replace them (and the others still on the crankshaft), but the pistons, to my untrained eye, seem good enough to re-use. Now the pistons are out, I can't see any obvious damage to the linings and they're still not leaking (the block is still full of water).

The next job, then, is buying a load of shells and gaskets...

Cheerio :)
 

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Tractor Damager
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128 Posts
Discussion Starter · #44 ·
Not a lot worth taking pictures of has happened this week - it's been more about figuring out what new parts I need.

A couple of interesting things for those who like serial numbers - apparently, with an engine number of 8686, mine's an early one and probably not the original for this tractor.

Anyway, I was talking to the parts place about new shells and they seemed surprised that I wasn't planning on regrinding the crankshaft. I've done the "standard" test of running my fingernail over the exposed journals and nothing catches, but I appreciate this is a pretty rough test... Should I just drop the crankshaft out and get it checked (and reground if necessary)? The same question with the pistons and liners, really - like I've said, engine rebuild kits come with both, so should I just replace them, even if they seem fine?

Thanks for any thoughts shared :)
 

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Not a lot worth taking pictures of has happened this week - it's been more about figuring out what new parts I need.

A couple of interesting things for those who like serial numbers - apparently, with an engine number of 8686, mine's an early one and probably not the original for this tractor.

Anyway, I was talking to the parts place about new shells and they seemed surprised that I wasn't planning on regrinding the crankshaft. I've done the "standard" test of running my fingernail over the exposed journals and nothing catches, but I appreciate this is a pretty rough test... Should I just drop the crankshaft out and get it checked (and reground if necessary)? The same question with the pistons and liners, really - like I've said, engine rebuild kits come with both, so should I just replace them, even if they seem fine?

Thanks for any thoughts shared :)
Just opinion here (but then that's what you're asking for). In my experience with tractor diesel engines, cylinders are rarely (if ever) still round and true when finally torn down to this point. Same with pistons. While they may appear serviceable, (and they possibly are, depending on your expected outcome and lifespan), they will never be "like new" again. New rings placed on used pistons will most likely never properly seat against used cylinder walls. No amount of polishing, honing, or whatever treatment you choose will solve that.

Then there is the outside of the liners, the part you can't see, where the liner meets the water jacket. The seals or O rings and their contact surfaces. More (so far) unanswered questions.

Would I strip the engine and turn the crank? Probably not. The rod journals are usually the weak link in the chain. All can be fairly well examined and measured with it still in place. If they check out, and there are no major issues visible on the main journals, I would leave it alone.

I wonder about the con rods though. Your description of the trouble and technique required for separating the caps from the rods makes me think they probably need at least some attention and machine work on the big ends. Possibly new bolts.

Budget, effort involved, time constraints, tools and equipment required, all factor in.

My opinion.... Your decision.
 

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Tractor Damager
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Discussion Starter · #46 ·
Hi,
Thanks very much for your thoughts...I'm in uncharted territory for me, in terms of how stripped apart my engine is, now, so I appreciate your shared experience.

I probably made my heavy-handed separating of the con rod caps sound worse than it was...there are a few small marks left by the drift, but they came apart fairly easily afterwards. The engine manual says to replace the cap bolts, although the rebuild kits don't seem to come with new ones...perhaps they think different?

On inspection, the pistons are quite worn and, presumably, the liners are too, so it's very much looking like I'll be swapping them out for new - thanks for your advice on that.

Quite close to payday now, so watch this space :)
 
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