Tue Oct 11, 2011 7:47 am
Something went very wrong while mowing. On my last pass of mowing an aweful clunk developed in the engine (sounds like a rod).
I shut the tractor down immediately hoping to minimize the damage and towed it back to the barn. Looks like I have some surgery to do.
Don't know the extent of the damage, but now I have a decision to make. Minimal Repair or a full rebuild. Won't know that until I open it up and take a few measurements. I have no idea how many hours are on this tractor.
Wouldn't you know this occurs when time and money are tightest. Just had 3 toddlers added to the household this week and all attention is going to them. I am certainly going to need some help from the experts.
Tue Oct 11, 2011 9:21 am
Did it lose any power? Did it start smoking?
Tue Oct 11, 2011 11:50 am
I didn't give it time to do anything. The key was turned within 3 seconds of the noise starting. It was a clunking noise at about 1/2 the RPM speed. I am hoping it's just a rod.
I wasn't working it very hard but was finishing up the mowing. Last week I worked it hard while tilling up a weed bed with the 3-point rototiller. The governor got quite the excercise that day.
Tue Oct 11, 2011 1:38 pm
Before you tear the engine apart, check the output shaft on the flywheel to ensure things are good and tight and not the source of the noise.
Tue Oct 11, 2011 2:33 pm
Outdoors, generally, when a rod lets go, the engine just makes one big 'bang' and sizes up. A rod bolt or nut could have let go or backed off.
I would remove the spark plugs and see if the engine turns over using the fan belt. If it does turn over, I would then motor it over using the electric starter. If all of that goes well, I would do a compression test. If that goes well, I would pull the oil pan and inspect the lower end - on the 184 the oil pan is very easy to pull and you can then easily look at the wear on the main and rod bearings. If the lower end looks good I would then disconnect the drive shaft and try to start the engine to see if the engine is really the culprit making that made the noise.
Let us know what you discover - NJDale
Sat Oct 22, 2011 5:36 am
Pulled the oil pan off and found the issue.
The crankshaft has a crack in it at the #4 cylinder rod. The crack is about an inch behind the journal.
A full lower end rebuild will be required.
Off goes the hood.
Sat Oct 22, 2011 7:43 am
Wow, I am VERY surprised at that !!! Crankshaft do break; but, it is very unusual. When they break, I often wonder if it was an original casting weakness/defect that finally let go. I guess the good news is that a good used crank won't be all that expensive. Probably the hardest part will be pulling the front pulley off the crank. I wish you the best with your rebuild. NJDale
Wed Oct 26, 2011 1:41 pm
Got the crankshaft out of the block. Looks like it has previously been rebuilt. Main Bearings and Rod bearings have been ground .010. Not that that matters right now, a replacement crank is required.
Did find one curious thing though, the pistons are .020 over and are FLAT! Haven't decided whether it is worth buying new dome pistons yet.
Anyone know where I can find a gasket set for the 184? The ones on TM are "Not for a 184".
Also, need some help separating the crankshaft pulley from the crankshaft. Anyone in Michigan have the "correct tool for rent"?
Wed Oct 26, 2011 3:59 pm
Outdoors, Well the 'mystery' as to why the crankshaft broke has been solved. The flat top pistons are made of cast iron and weigh a 'ton'. These pistons are found in the red Farmall Cubs and the block has a serial number below 264567. The engines that used these pistons were meant to turn approximately 1,800 RPM. The cylinder head that was used with these cast iron flat top pistons was part number 251228R11 and produced 6.5 to 1 compression. This engine produced Horse Power in the range of 9 to 10 HP at about 1,800 RPM.
If you were running these heavy flat top iron pistons at 2,400 to 2,500 RPM - this is the reason that the crankshaft broke.
With the introduction of the 154 and engine serial number 264568, IH introduced the aluminum dome topped pistons which were good for 2,400 to 2,500 RPM's due to the significant reduction in the piston weight. The original 154's came with cylinder head #351779R91 (which was the 'high altitude' Farmall cub head) and made a compression ratio of about 7.0 to 1. These engines made about 14 HP at about 2,200 RPM.
On the 185, the Cylinder head was changed to #355691R2 which increased the compression to 7.5 to 1. The intake/exhaust manifold was changed to a model that had a 3/4" intake diameter at the carburetor flange verses the previous 5/8" diameter. The carburetor was also changes to Zenith #13781 which had an increased matching flange diameter of 3/4". Both the 185 and 184 engines produced about 18.5 HP at just under 2,500 RPM.
The aluminum Pistons are matched to different connecting rods than the cast iron flat top pistons. The cast iron pistons used connecting rod # 251246R13. The Aluminum pistons used connecting rod #527457R11.
As far as I know, the blocks for all C60 engines were the same. I believe that all the C60 engines used the same part number crankshaft - although an unsubstantiated rumor says that the 184 used a 'stiffer, induction hardened' crankshaft. But again, I found no difference in the IH part numbers - so I kind of doubt that there was a change made.
The 184's (and possibly the 185's) used a 'rotator cap' on the exhaust valve to ensure that the exhaust valve turned to keep it from burning after lead was removed from the gasoline.
I do not know if the governed speed was changed by changing the springs or weights or both - inside the governor.
The next step I guess that you need to make is to get the engine serial number and the head casting number.
Felpro makes a 'rebuild' gasket set for the C60 engine. It is Felpro #FS7560S. Napa has it for about $70 to $75.
If your cylinder walls are in good shape at .020" over - I would contact Hamiltonbob to see if he has a crankshaft, and four .020" aluminum dome topped pistons with connecting rods. If your head is the wrong one, he might also have a #355691R2 head. All of these pieces should be UPS-able. The only things new that you would then need are gaskets, rings and bearing.
PM me with your 'real world' email address and I will send you an Excel spreadsheet with many 184 engine part numbers and sources.
Thu Oct 27, 2011 5:12 am
This summer I had re-adjusted the governor on my 184 to meet the 2450 RPM specification. Before adjusting the governor, it was running 1800 RPM's. I suspect that running at this higher RPM with the steel pistons really put a lot of undue stress on the crank.
I am going to swap out the pistons and verify the part numbers of the rods. Rings, Main & Rod Bearings will get replaced with new.
The cylinder walls are in excellent shape and there is minimal wear so I am not going to bore it any further at this time.
Sat Oct 29, 2011 1:28 am
That sounds like the problem we had with ours in the early 70's. My father bought a 154 new from the dealer in Delaware and after a very short time it broke a crankshaft. IH replaced it with a new crank and after a very short time it broke the crank again. Come to find out the dealer later told us that IH had a problem for a very short time with the line bore machine on the assemble line as the machinery was getting worn from so many years of use.
Sat Oct 29, 2011 1:32 am
I have a question. I understand the cast iron vs aluminum piston idea, but didn't the early c60 power unit turn up close to 2300-2500 rpm's
Sat Oct 29, 2011 6:45 am
Because peak torque occurred at about 1600rpm. The later engine upgrades raised that peak a little.
Wed Nov 30, 2011 1:32 am
Well I never expected a rebuild to take this long, but the crank is finally back from the machine shop and I now have the rod and main bearings in hand from TM.
I did spring for the (Super Expensive) aluminum pistons. The IH dealer is the only place I could find .020 over pistons that were dome topped. (not really dome shaped, more of a malformed tumor on the top-front of a piston).
This tractor just moved to hobby status as I cannot recoup this investment.
Should I use copper-cote on the front cover or high temp RTV? (yes I have a new gasket to go in there) I don't want to risk oil leaks so I am leaning toward the RTV.
Wed Nov 30, 2011 9:16 am
If you've never used it, give Indian Head Varnish a try on the front cover, or any other part that touched oil. RTV would be ok, not copper-cote though, unless you mean just the bolts
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