Cub suddenly seized (and other things..)

[jastusa]

Hi Team,

I purchased my Cub that was not in running order and had absolutely no wiring, so over time I have:

Rebuilt distributor fully due to water ingress/seizure
Added brand new carby, and adjusted float as per manual
Rebuilt Governor due to water ingress/seizure
Converted to 12v, all new wiring , alternator, coil etc *followed instructions from a fellow on youtube (just tinkering)

In the last week I have attempted to start this beast, which is what it seems to be becoming, and had some initial timing issues, as I was working off the first timing mark, and not the second, and was then 180 degrees out. Atfer all that, I'm 100% sure I was at TDC on No1, though she still simply wouldn't fire (yup, leads on in correct order on the distributor posts, checked spark on all 4 and coil).

This lead me to a local tractor pull, where it was suggested by some more experienced campaigners that I check valve clearances (keep in mind I had very good suction at the air intake via my palm, though admittedly I didn't check compression due to lack of required tools, which I have now borrowed). The other observation was the plugs had no fuel on them, they were bone dry, and look brand new btw.

So, it was off with the valve cover, and had a look and nothing seemed to be stuck, as I was turning the engine over attempting to start and the valves were moving as expected, though she still didn't fire.

All of the above is context, as I went out to the shed this evening and attempted to find TDC and the engine wouldn't turn over, it's as if there is a major bind or something stuck somewhere; I couldn't move the pulley by hand or with the crank, so my question on this matter is; Could it be the starter somehow causing a bind, if not, what else, as it was fine a few days ago (and I didn't adjust the valves, because I'm still reading the manual on this)?

The second question I have, which comes from me wanting to take a look inside at the pistons/valves, is that I noticed what seems to be a repair to the head, which you can see from the attached pics, along cylinders 2,3,4. Is that common place on these engines? I can't see a crack underneath btw, and unfortunately ordering a new head isn't that simple as I'm in Australia, though am wondering if this could result in a compression issue. As you will see though, the head is now off, and I'm now on the computer, so won't know until I put it all back together.

Anyways, go easy on me, I'm not a mechanic, as what I have described is what I have pretty much learnt in the last month (well, I did do the wiring a while back).

cheers,
jason.

[coppersmythe]

good morning (here) from the deep south in loisiana, USA . my first guess would be the head had a freeze crack in the water jacket part of the head . i just had a similar one . it was repaired with JB weld , i dug that out and brazed it . check to make sure the other side facing the pistons is not cracked . look very closely , magnifying glass if you have one . compression test would really tell the tale . pull the starter and find out if that is the gremlin thats stopping the engine from turning . good luck , keep us posted , you will get the best help here . others will chime in . great bunch of folks with way more knowledge than me . coppersmythe............................

[ricky racer]

Welcome to the greatest Cub website on the planet!! First thing I'll ask is did you prime the oil pump prior to trying to start it? If not, there's plenty of threads on here describing how to do that. If the starter is the problem, it's a quick and easy thing to check out. Simply pull the 2 bolts out of the starter mounting and pull it from the housing. If the engine still can't be turned over, it's not the starter. The next thing I might try, assuming the head is still on the engine, is pull the spark plugs and see if you can turn the engine over with a crank. If coolant comes out of the spark plug holes, then you know that the head repair didn't work and you've likely have a cracked head or another issue (head gasket, cracked block, no sealant on the head bolts, etc.).
You mentioned that you inspected the valves to see if they were moving but did you check the clearances? If they are too tight and not fully closing, you may not be getting enough suction to draw fuel into the cylinders. You said the plugs were bone dry so that is something to check out.
Check these things out and report back with what you find.

[Barnyard]

After you pull the starter, take a large screw driver or a medium sized pry bar and see if yo can turned the motor backwards. You may have a spot on a cylinder that is causing it to bind at just one point.

[outdoors4evr]

Most people check the accessories to the engine first.
Ricky mentioned the starter. That's a good thing to check.
Fan hub needs lubrication. Remove the fan belt and See if you can turn the fan by hand (ignition off)
Generator or Alternator (if equipped) Remove the fan belt and see if you can turn by hand.
Hydraulic Pump. Not a good way to test this except to remove it. Start by making sure that the TC has oil available.

Weird other things - Make sure the tractor can roll. If the transmission is stuck in two gears, then the engine won't turn over without the clutch being depressed. (a lot of operators start their tractors with the clutch out) Try to start the engine with the clutch depressed. If engine turns over, then the issue is behind the engine (transmission or PTO)

Hmmm... After that you are tearing into the engine to find the issue. Perhaps the engine ran without proper lubrication (re: prime the oil pump suggestion above) and the rod or main bearings seized?

[Glen]

Hi,
The valve clearance on a Cub engine is manually adjusted, using a feeler gauge.
If nobody adjusts them, the clearance at the bottom ends of the valve stems can get too small, then the valves might not close fully.
Below is a page from the 1949 Cub owner's manual, telling how to adjust the valve clearance.

http://farmallcub.com/rudi_cub/www.clea ... age-39.jpg

The valve lifters have to be fully down, when checking the clearance. They can't all be fully down at the same time, so you have to turn the engine at times to check the clearances.

[jastusa]

Hi again team.

*Saturday night here in Oz, approx 10pm.

Thanks all for the detailed responses to my questions, as without the advice I wouldn't be able to report that the Cub is now running; I can't believe it!

I went through everything described, and was firstly able to free the bind by removing the starter and pushing down on the flywheel as suggested by Mr.Barnyard et al. I'm not sure where or what was stuck, but I do believe having the head off and some oil on top of the pistons helped.

From there I was able to determine exactly TDC as the head was still off, and verified the rotor was lined up in no.1, ruling out timing. I purchased a set of feelers (and a torque wrench), made the adjustments as suggested and put it all back together, and boom, she was running, though there are some residual issues, and new issues. The compression (err, 'wet' test as I had oil in the cylinders?) test had all cylinders at just on/under 60psi, which seems low from what I have read in the forum threads. Obviously the tractor starts/runs, maybe the gauge I used is out?

Now, when I had it running, I placed it in forward/reverse, stalled very easily, and I could hear the engine take some load when the clutch was depressed. In the end, I got it forward about a meter, and then noted a bit of smoke coming out from bolt holes and the viewing hole under the clutch. There was a part inside behind the clutch, that after reading some strings in the forum, I'll call the 'throw-out bearing', which has a grease nipple. The bearing was very hot, and I don't know why, as I had only driven approx. 3 feet (the tractor was probably running for 10-15 mins before I attempted to drive forward). Any ideas what's happened here - I turned her off as soon as a noticed the smoke/burning smell. I wasn't riding the clutch either, pic attached also.

Lastly, and this might be for another day, the PTO is free/not engaged (and I'm able to turn the shaft easily by hand), but the lever to engage is seized up. Is that a common occurrence?

Regardless, lots of progress today, thank you for the assistance and suggestions.

cheers, jason.

[Dale Finch]

If you did not have the clutch pedal depressed when that photo was taken, it looks to me that your TOB (throwout bearing) is touching the fingers, while there SHOULD be about a 1/8" gap. If this is the case, the result would be the same as riding the clutch.

I don't remember what year your cub is, but with the earlier cubs, this gap was changed by turning a clevis behind the TOB inside the clutch housing.

The later cubs have an external adjustment at base of the clutch pedal. The procedure is in the manual, or you can search relevant posts here.

If you have not already done so, check that the clutch fingers are adjusted to 1 1/4". That procedure is discussed ina HOW TO, I believe.

One last thing, as you noticed, your TOB has a grease zerk fitting, and opposite that fitting is tiny hole. As grease is applied, the excess will squirt out that hole. It has been said that the TOB needs to be able to absorb the oils in the grease, an the "cheap" grease is the best choice, since it will be abosrbed better.

[Dale Finch]

Here is a link to the CLUTCH section of the HOW TO posts. You should find lots of info there that will help you.

One thing you probably already know, when you installed the head, most folks use Copper Spray-a-Gasket, and a sealant on the head bolts, since they extend into the water jacket. From that same section linked above, there is this HOW TO for head gasket replacement. The head bolts need to be retorqued after running for a while.

[Waif]

It's (for me) back to the one thing at a time.
Clutch has been adressed by Dale.
Manual pics and a study of adjustments before you plunge into it should help.
Note your clutch pedal adjustment and it's spring's condition too.

Your P.T.O. will be another one thing subject ,but after your clutch is happy...
Manual(s) to study first will again be your friend. And make it easier to communicate any questions you may have.
Basically ,your lever moves a splined coupler (so to speak, we could call it a crude clutch but coupler works for my lizard brain better) to a position where it bridges the gap between two shafts to drive the rearmost shaft.
That coupler , the lever and it's basic linkage ,the shafts ends alignment , and bearing conditions all matter.
An easy study once you've looked it over in the manuals.
A wild guess it your coupler is not wanting to slide. But that's only a guess.

[Eugene]

From there I was able to determine exactly TDC as the head was still off, and verified the rotor was lined up in no.1, ruling out timing.

Not quite. Since tractor runs you need to either static time the engine or use a timing light.

The compression (err, 'wet' test as I had oil in the cylinders?) test had all cylinders at just on/under 60psi.

If the engine was running before the compression test, it would be a dry test. Engine oil on top of the cylinders would have burned off.

Operate the engine for some time, many hours, then take the compression tests again. Also use some additive to the gasoline and engine oil to help free up the rings. Usually suggest using Sea Foam. Not sure if it's available in Australia.

As previously stated, work on one issue or repair at a time. When that task is completed and works, move on to the next issue.

Kind of an edit. Keep battery fully charged. Weak battery can cause the starter to lock up in the flywheel.

[Glen]

Hi,
It look like in your pic the Cub is serial number 30443.

It looks like in your pic of the clutch that the Cub has the 1st style of throwout bearing holder, so it has the 1st style of clutch pedal free play adjustment.
You have to turn the yoke on the rod to adjust the free play.
That was used on Cubs up to serial number 32229.

Below is a page from the 1947 Cub owner's manual, showing how to adjust the pedal free play.

http://farmallcub.com/rudi_cub/www.clea ... age-40.jpg

The free play is measured at the surface you put your foot on.

Be sure there is a pedal return spring under the platform. It holds the pedal up against the edge of the platform. If it is gone, the pedal can fall forward, and the throwout bearing will rub on the 3 pressure plate fingers. Pull up on the pedal by hand, and see if it moves up, or if the spring is there.
The brake pedals use the same style of spring.
Below is a listing for the spring at TM Tractor.

http://www.tmtractor.com/new/cl/864fp.htm

Be sure the clutch pedal moves freely at it's base, in the clutch housing. They sometimes get tight there, from no lube. If it is tight, work penetrating oil into the pivot.
The pedal may pull out of the housing 3/16" or so, if it will, that is helpful for working oil into the pivot. Oil it with motor oil when it's free moving, and push it back into the housing again.

I put a thin layer of grease on the front of the throwout bearing, it helps reduce friction. Part way around is enough, the fingers will spread it around.

Below is a pic of where the spring is. The pic is of a brake pedal, the clutch pedal spring is in the same position on the clutch pedal.

[jastusa]

Thanks Dale, Waif, Eugene and Glen for those latest replies, unfortunately I didn’t get a chance to work on it today, but will do over the next week/weekend.

One observation though Glen is that the spring you mention is missing, so I’ll see if I can fabricate something, else will order from the US (noting I’m building an inventory of required parts, namely gaskets and possibly larger items).

Many thanks, Jason

[Dale Finch]

There are not many gaskets that cannot be made by you, with a selection of gasket materials from an auto parts store, and the two common bolt hole-sized punches. One example of a gasket that requires a specific thickness is the one for oil pump...that one is "critical". There are probably others.

Maybe you need to follow Donegal's action, and come visit the US in Feb for the DSCF (Deep South Cubfest) in Sneads, FL. You can preorder your parts with a US delivery, meet some good forum members, get some hands-on experience, eat some great food, and pick up your parts! Some of us drive almost as many hours as a flight for you would take!!

[Eugene]

There are not many gaskets that cannot be made by you, with a selection of gasket materials from an auto parts store, and the two common bolt hole-sized punches. One example of a gasket that requires a specific thickness is the one for oil pump...that one is "critical". There are probably others.

Hole punches for gasket material; bullet shell casings and many other items including a ballpeen hammer. RTV works great for some gasketed areas.

Many Cub repair items are common hardware store supplies. Do not over look tractor dealerships for other makes, auto parts stores, and industrial construction/machine supply stores.

The brake return spring. My local hardware store stocks as selection of springs.