Stuck - with no pistons?

Allis B. Was a running tractor 3 years ago. Would not turn over with crank or electric start. Was hoping to free it up at little or no trouble. ATF in holes for a month, no go. Pulled the valve cover, exhaust valve stuck open on #2, bent exhaust push rod on #3 (like in a Z shape!). Pulled the rocker shaft, still stuck. Pulled the head, #2 and #3 exhaust full of bees! #2 exhaust valve stuck open abut 1/4". Got it to move but stull sticky so assuming it's bent. Cleaned bees out of the cylinders, no real rust, Kroil'd, tapped, pounded, could get #1 and #4 to move around in the bores, some movement of #2, but no going up or down.

Dropped pan, no obvious issues other than oil pump pick up screen coming loose. Had some fun pulling cotter keyed rod bolt nuts, those things probably had 150lb/ft torque. Wooden rod, tapped #1 and #4 out no problem, look pretty good, a little worn but certainly not stuck. #2 and #3 are on the up stroke, crank is at that place where there is not enough room to get the rod end between the crank and block. But, I tap #2 up so the rod is loose on the crank. Motor is still stuck. Tap on #3, piston move up, now crank is free to swing.

NOT!

Finals are free, I can roll the tractor around in neutral, locks in any gear. Cannot spin the crank with hand crank or starter, any gear or neutral, with the clutch locked out.

If the clutch was stuck I still should be able to spin the crank and shaft. If the trans was jammed I would suspect that it wouldn't shift into all the gears, or that it would be locked even in neutral.

I'm kind of stumped. Guess my next step is to split the tractor and see if I can spin the crank with the drive shaft off. But before I do that I thought I'd ask for any other ideas.

BTW it's 10 degrees out, gravel floor barn with no heat, which explains my lack of ambition. But the tractor was stuck when it was 80 out so I'm comfortable that it's not just ice. I also had checked for water in the trans and finals before it froze out, all was good.

Bent or broke crank could do it, and have you checked the valve gear train, all it takes is for a broken bit of metal or 2 to gum up the works.

On these motors AC used an offset rod setup. Two rods go in one way and two the other. My recollection is one and four go the same way and two and three the opposite way. If the rods are not in properly the engine will bind and not turn over as it should. If it is forced to turn over you can actually bend the rods that are not installed properly. HTH. Best Yeoman

Does this tractor have a starter? If so have you pulled it out to make sure it is not jamed? Just a thought! Roger

I agree with Roger pull the starter and try turning it over then.

Look and see if you have any bolts in the bell housing sides. If a bolt got tightened in one of the holes and was a tad to long it will hit ahd hold the flywheel from turning. Like I said on an earlier thread, I have read more than once where a person has removed the head and pan only to find a started locked into the ring gear.
Spun main gearing will bring the engine to a halt also.

TerryMtAuburnIA wrote:

Could anyone give me any advice on how to un stick a motor that has been stuck for about 7 months. No rust really, have top and bottom off and all 4 pistons soaking in PB blaster for two weeks and I have a hand crank in the front. What can I safely hit it with to bust it loose. Thanks in advance.

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(NO RUST REALLY)



If you have both the top and bottom off it would be my guess with no signs of rust that it is not the pistons that are stuck. I would start looking at the flywheel first or next for a spun bearing.



I have read more than once of the head and pan being removed only to find a locked starter.

If it is a B, C or CA you can also have a cap screw on the bell housing screwed in tight on the flywheel.

Pulled out starter, starter nose was stuck but bendix was free, motor still stuck.
Pulled front end and the snow plow off, pulled all the accessories, then bit the bullet and pulled the motor.

Crank spins fine! So somewhere aft of the flywheel is my problem.

I'll check all the bolts in the torque tube (has a snow plow on it which is why I didn't really want to tear it down)ut I can't see any on the inside. So the trans must be jammed. Darn it!

Do you have bolts going through the bell housing that may be too long hitting the flywheel?

Pull the inspection plate on the tranny, I think the B has one (it's been a while since I had one!). See if you have the tranny shifted into 2 gears, at the same time. Could be a bent fork, broke fork, or loose shifter gate.

Pulled the engine free of the tube, crank spins freely. Reached in, can turn drive shaft and drive wheels no problem. Hmm.

Pulled engine away from tube far enough to see, and mud dauber nests started falling out. Lots of them, made of rock hard yellow clay.Basically they encased the flywheel to the point I couldn't break it free with rotation only, but once I pried (and that was the key, I had to pry) the engine forward the grip was broken!.

So my 'stuck' engine turns out to have a bent valve, a bent pushrod, a bad throwout bearing (rough, and catches), and a whole lotta mud.

Last winter when I went to move the tractor, right final was locked, removed the frozen water soaked mouse nest from the brake drum area and all was good. I also removed probably 20 wasp nests out of the tin. I guess the critters love Allis B's as much as I do!