IH 674 rebuild questions

I began slowly tearing down (in-place) my '76 674 D239 this summer, after it wouldn't turn over summer 2015, wouldn't even budge with a bar at the pulley. It sat uncovered, and as one might expect has seized due to rust. I was hoping for a little rust on the sleeves, I could free it up, but no, it's everywhere. The head has been removed, and checked. The pistons were stuck in the sleeves, and #4 was pushing the sleeve out with the head off (with a pry-bar at the flywheel). I got the pistons out to replace rings, and possibly hone the sleeves. While that far, I planned to replace all connector bearings. From cylinder 2-4, the amount of inner rod bearing wear increases from the embedded specs I see stuck on the crank. Given the amount of wear on rod bearing 4, and the seized piston bearing... and the fact that I can't turn the engine (out of gear) by hand from the pulley with no pistons, I think I should also replace the mains. This is becoming difficult, considering I've never done a split, and the work must be performed outside on uneven ground.

Should I be able to turn the engine at the pulley by hand without pistons or head installed?

Is there absolutely no way to replace the main bearings and seal without splitting the tractor? Say as one might remove connector rod bearing upper half in a stationary piston and crank position. I really don't like working under or around that much weight if it's got to be split.

I think I've found the rod bearing size after a lot of digging, but not exactly what I read from the manual as .01, .02, or .03, which I assume are clearances. I was told the size would be stamped on the bearing. The rod bearings are from two different manufacturers Clevite77 CB-1044P 0,50 7B, and some other manufacturer I can't determine T/B GS175LB 0,50. I assume these are not standard, as they are not stamped STD, and I assume also that they are +50mm (~+.02") over (finally found some reference today), whereas I've been hunting specs in inches. My tractor is the European model, so maybe that's why, but I've been trying to figure this out for a few weeks now.

This motor has been rebuilt once by the previous owner who is now deceased. I noticed the rod and caps have numbers stamped into them, opposite from the cylinder number. Two are legible, two not so much. Am I correct in assuming those numbers are the size of the bearing for that particular rod/crank journal combination? One of the rod's (#4) stamps has some more recent markings over the numbers, which do not make sense, but it also has the most wear. I suppose I could measure for tolerance, and buy the appropriate sizes. I'm just curious.

Any information would be appreciated. I have all of the manuals for the tractor, mechanic experience, and tools, minus any splitting stands.

Thanks in advance,
M

I would just have your rods reconditioned, it'd be a good idea. If it seized up due to rust, you would be better off to replace the sleeves and pistons, doing an in-frame basically. The rear main seal cannot be changed without a split, but the main bearings usually can be. Loosen all of the main bearings, find a small pan head screw that will slip into the oil galley hole, make sure the head is large enough in diameter to not allow it to completely slide into the oil galley in the crank, and make sure the head doesn't stick up higher than the thickness of the bearing. Once you put the screw in the oil galley hole in the crank, gently turn in by hand, and the screw will roll the bearing out, assuming you roll it the right way and arent trying to roll the bearing tab the wrong way. Do you have any pictures of the markings on your rods? What about your clutch? Is it seized up and causing the crank to be hard to turn? I would think with no rods/pistons in it, you should be able to turn it over by hand possibly.

Ross

Thanks for the response, and the tips. I will likely split it after watching a video last night, I have everything to do it with. Just not looking forward to realigning to the clutch. I don't like doing anything halfway.

I have attached images of rod 4 with markings over the numbers (sleeve size?), the most worn rod 4 bottom sleeve, and one of the 4 rusted rods. Rod 4 was the only one with additional markings found.

Just curious why I should consider replacing pistons? Don't the rings and sleeves get all the wear?

I'm sure the clutch isn't frozen, since in a last ditch effort to get the engine to turn, we tried to pull it slowly dumping the clutch. I could clearly feel the clutch engaging and disengaging. It stopped the tires completely in 2 low, and the clutch slipped in 4 low. However, the lever could have fell into gear with me slow turning the flywheel, and I could hear some resistance sound coming from the starter hole when turning. I'll double-check that it's still out of gear, but there's absolultely no tire movement, so I assumed it was still in neutral.

Thanks again.
M

Well the images didn't take for some reason. Let's try again.

Hi Radarjr, when I split a 74/84 series tractor and when I re-assemble it I just put the clutch and the pressure plate on the
transmission and PTO shaft, then all you have to align is the transmission shaft into the pilot bearing. Then after re-assembly
the pressure plate can be bolted to flywheel through the bottom inspect plate. The engine can be turn by bumping the starter or by
removing the starter and using a pry bar on the ring gear.

JimB

Well... I think that
you have made a wise
decision to split it.
If that rod is that
rusty, I'd be afraid
that you have cam
lobes or lifter faces
that look like that.
Furthermore, I myself
would be afraid that
if ALL of that rust
was not removed from
EVERYTHING in that
engine, that the
general stresses of
running (once you get
to that point) would
cause it to loosen up
and find its way into
your oil, oil pump and
bearings quicker than
not. I always err on
the cautious side when
doing engines. Your
crank is good and
smooth without ridges?
That looks like quite
a bit of embedded
metal in those
bearings, any idea
where it came from? My
point on the pistons
was that if a high
houred engine, the
ring lands can and do
wear from the rings
"rubbing" on them as
the piston goes up and
down, and you are
already that far down
with it. Are all of
your sleeves rusty? Or
are the others just
fine surface rust and
4 is the bad one? If
that was the case, I
could see reusing the
piston and just re-
ringing it if
everything checks out
ok. But sometimes if
you buy sleeves,
bearings, gaskets
separately, for just a
little more you have
new pistons too, and
then everything aside
from cam bearings has
been done. I believe
that #4 rod might be a
replacement rod that
was #1 on a different
engine. Whenever I
rebuild an engine, I
stamp the date, and
main and rod brg size.
If that was the size
of the bearing, it
would most likely be
stamped .010, .020,
.030, I don't know
what all size
undersized bearings
are offered, those are
just pretty commonly
offered sizes. What
does the back of the
bearing say? They
usually have the
number on the back of
the bearing if
undersize, USUALLY, or
STD if standard size.
If not, Google the
part number on them,
and see what comes up.

Ross

Good to know JimB. I noticed the inspection plate. That helps.

I can see loose rust that has landed on the cam lobes, but the cam doesn't appear rusted itself; I'll look closer with a light. I can also feel rust build-up on the crankshaft web faces, and saw more on the crankshaft gear that turns the middle counterbalance. I agree, all that loose rust would just end up back in the bearings, taking me right back to the beginning. The crank journals have minimal embedded grit (#'s 3 and 4), causing some wear on the rod bearings. The #4 bearing you see is dramatically worse than any of the others. Which made me think the rear main must also look similar. All of the cylinder sleeves have very fine rust, and hardened black material at the top, so I was hoping to just hone them, but it'd be easier to just replace them, and not worry about tolerances. I'll measure the piston lands and compare to the manual.

The picture #4 rod has the original 4 stamped into the other side matching both upper and lower portions. I was assuming the markings on the 471 side were indicating the size was not as specified. I have indeed seen the stamps on the back of the bearings, which I've recently determined are in metric measurements/tolerances noted as 0,50, and that's definitely a comma. The middle two rod bearings have old part numbers that I couldn't cross reference, but #1 and #4 were Clevite77 bearings CB1044P with a good part number. So, I'm pretty sure the bearings I have are .02", which is .50mm. Not sure why the comma in the stamp.

I'll post additional images below, and hopefully caption them this time.

Rod bearings 3 and 4, much less wear than #4

Rod bearing stamp on 2 and 3, I cannot trace this part number or its manufacturer, but 0,50 is common to that stamped on the next picture, which I can find.

Rod bearing stamp on 1 and 4, which I can find replacements for. I assume based on what I've found, the 0,50 is metric.

piston 4 with seized pin/bearing, and gunk.

#'s 2 and 3, not 3 and 4