Found the problem

[Lynerd]

Working on my friends 450 a few months ago and found no compression on 3 cylinders. Figured stuck valves but that seems odd as they get lots of oil topside. He pulled it over to the shed and got cooler weather pulled tappet cover off and cranked motor over. No valve movement. I was wondering what would be the cause of this. Lynn

This is what I posted in Oct of 2022. I had a motor out of a 400 and told him I would build him a short block. He has had other people working on it and trying to follow some is not the best thing to do. Took the short block to an Amish fellow and he tore it down and put the block in and I helped him install the head and put all the accessories on and got it running. This was the result but don't know what caused it. It had the DB gear. Lynn

 

[Mrfred54]

Seen that happen on Farmall M that the owner installed a hydraulic pump but didn't install the heavier gear for the extra load that the pump required. When the super M TA came out their was some issues with cam gear failure and that's when the heavier gear became available for the extra load from the pump. Maybe somewhere in the last 70 years someone may have installed the wrong gear.

 

[rustred]

was a common problem with this camshaft gear thing. i think back then equipment was not as heavy to lift so they got away with it. years later everything got heavier and it took more pressure to lift implements, especially when using a smaller than required cylinder say 2 1/2 vs 3 inch. the 3 inch will lift quite easily. plus the old john deere cylinders were low pressure and would blow up if used with a more modern tractor with high pressure. ihc usually had things figured out pretty good but this cam hydraulic thing i dont think much of either. but i was better than pulling a trip rope. the earlier pto Charlynn hyd. worked ok but it was not live and u had to plan your thing in advance.

 

[used red MN]

I think you know this rustred, but the DB suffix on the gear he mentioned should have made it the latest revision to handle the load. The DA suffix is also acceptable however the DB is the latest. Gears with just a D suffix are the stock M gears. Nothing man made is perfect, so occasionally things just break. Hopefully, the relief valve is not stuck or the pressure is not shimmed up to high.

 

[BarnyardEngineering]

Even the 400 and 450 cam gears would break once in a while, as I understand it.

That's why IH moved the hydraulic pump to the transmission.

 

[Janicholson]

Helical gears have axial forces applied to them under drive conditions. On the crank drive gear the teeth push the gear axially toward the engine. on the driven side those same helical teeth driving the pump also push the cam gear toward the engine. Even the governor driven gear to a much lesser extent pushes rearward on the rim of the gear. Looking at the gear being held in the supplied image (though flipped front to back in the picture) shows a break that indicates that the gear failed toward the engine, not diagonally or from tooth breakage. My observation. Jim

 

[Lynerd]

Seen that happen on Farmall M that the owner installed a hydraulic pump but didn't install the heavier gear for the extra load that the pump required. When the super M TA came out their was some issues with cam gear failure and that's when the heavier gear became available for the extra load from the pump. Maybe somewhere in the last 70 years someone may have installed the wrong gear.

 

[Lynerd]

Seen that happen on Farmall M that the owner installed a hydraulic pump but didn't install the heavier gear for the extra load that the pump required. When the super M TA came out their was some issues with cam gear failure and that's when the heavier gear became available for the extra load from the pump. Maybe somewhere in the last 70 years someone may have installed the wrong gear.

Mrfred54 It had the heavy gear in already and the cam rotated freely so must have been in pump. Lynn

 

[Lynerd]

was a common problem with this camshaft gear thing. i think back then equipment was not as heavy to lift so they got away with it. years later everything got heavier and it took more pressure to lift implements, especially when using a smaller than required cylinder say 2 1/2 vs 3 inch. the 3 inch will lift quite easily. plus the old john deere cylinders were low pressure and would blow up if used with a more modern tractor with high pressure. ihc usually had things figured out pretty good but this cam hydraulic thing i dont think much of either. but i was better than pulling a trip rope. the earlier pto Charlynn hyd. worked ok but it was not live and u had to plan your thing in advance.

rustred It didn't have power steering so I put a stock M coupling after modifying the holes to replace pump to keep it from happening till we got it running. Then the warranty went off and they could put pump back on and see what happens. Lynn

 

[Lynerd]

I think you know this rustred, but the DB suffix on the gear he mentioned should have made it the latest revision to handle the load. The DA suffix is also acceptable however the DB is the latest. Gears with just a D suffix are the stock M gears. Nothing man made is perfect, so occasionally things just break. Hopefully, the relief valve is not stuck or the pressure is not shimmed up to high.

red MN As I told rustred I took pump off till we got it running and with no power steering didn't need it. I don't know much about hydraulics but figured something could be wrong in that area. Lynn

 

[Lynerd]

Even the 400 and 450 cam gears would break once in a while, as I understand it.

That's why IH moved the hydraulic pump to the transmission.

BarnyardEngineering Proof here. Lynn

 

[Lynerd]

Helical gears have axial forces applied to them under drive conditions. On the crank drive gear the teeth push the gear axially toward the engine. on the driven side those same helical teeth driving the pump also push the cam gear toward the engine. Even the governor driven gear to a much lesser extent pushes rearward on the rim of the gear. Looking at the gear being held in the supplied image (though flipped front to back in the picture) shows a break that indicates that the gear failed toward the engine, not diagonally or from tooth breakage. My observation. Jim

Janicholson It still would take a lot of force to do that wouldn't it? Lynn

 

[Janicholson]

Janicholson It still would take a lot of force to do that wouldn't it? Lynn

It is a lot of force. 1500psi generated by the pump and impulse pressure from load changes and things can be troublesome. The gears break as this one did, move and backout the retaining nut, and ruin the cam snout in some cases. Jim

 

[Mrfred54]

I didnt look close up at the gears. Yes the DB suffix is the latest gear. Bet he has a hydraulic issue.

 

[Bob M]

I had the same failure on my late production 1953 Super M (with the heavy cam gear from the factory). And a friend's 400 broke a cam gear too. Not uncommon on tractors where the hydraulics are regularly worked to capacity.

 

[glennster]

is the relief valve stuck or set too high? deadheading the pump can break the cam gear too.

 

[AJB-450]

I had the same failure on my late production 1953 Super M (with the heavy cam gear from the factory). And a friend's 400 broke a cam gear too. Not uncommon on tractors where the hydraulics are regularly worked to capacity.

Same thing happened to me on my dad's 400 back in about 1960 when I was in HS. Was plowing in some red clay with our 311 plow and needed to lift the plow. Camshaft broke and the engine stopped. Our local IH dealer actually had two camshafts in stock and they had it fixed the next day. I still have the 400 and it never broke again. That was about 65 years ago. Al

 

[Lynerd]

is the relief valve stuck or set too high? deadheading the pump can break the cam gear too.

glennster I took the pump off and installed a coupling from a M after modifying the holes. The owner can hook the pump back up when we are done with. I am not messing with the hydraulic system. That is when the warranty is done for me. Lynn