Super M hydraulic problem / motor problem

Hi all, I've been reading the forum for a while but finally ran into a problem that I can't fix by searching old posts so I'll post it and hopefully one of you can help.

My super m has always run great but the live hydraulic pump was pretty much blown out. I tried to take it apart and fix it up but it was too sloppy to make any decent pressure. So I bought a new pump ($ouch) and got it installed today. It seemed to be pumping great and then I went to lift my hay rake to see if it could do what the old pump or my dads m couldn't. Tractor was just above idle and It lifted the first stage of the rake like both my old pump and my dads m could but when the second cylinder activated it didn't lift it. I could hear the engine bog down a little with the pump trying but it didn't make enough pressure. So I revved it up and hit the lift lever again and it started to lift the rake but then the engine died. It acted like it lost spark instantly and just spun down to dead with a few pops from the muffler and a big backfire at the end. I tried to re start it and nothing but a lot of popping and sputtering but won't run. I pulled the dist. Cap and it's turning with the engine but acts like timing is way off. I thought maybe I skipped a tooth or a gear somewhere so I adjusted timing by twisting the dist. And after trying both ways no improvement. Also it seems to turn over odd, like un even, like I fear the cam isn't spinning or a cylinder blew or something. On the bright side though the new pump seems to work great! I just hope the tractor I put it on didn't die in the process...

Two possibilities.

1. Sheared the key on the hydraulic pump drive gear. It turns the distributor without any demand on the pump, but I bet it would stop turning if you activated the hydraulic remote.

2. Broke the cam. Hopefully not, though.

I would much more suspect that #1 happened because that's where the stress is. It's happened to me a couple times, but hasn't happened since we added a 5 gallon reservoir for the hydraulics. The belly pump tank simply wasn't big enough.

Wow thanks for the quick response! That's a good point about the gear without a key still spinning without a load. I will check that this evening and see if that's it. I hope so

i just got a chance to check and its not the gear on the pump. Turn it over and the starter spins the engine fast, push the lever while turning it over and it bogs the starter right down but the distributor spins the whole time. That's so sad because I finally got this thing in really nice shape for doing hay and i was so happy with it I took it in to dyno a few days ago; it makes almost 50hp. Well it used to make that I guess. I even ran a disc bine with it last year just to see if it would and she ripped that thing along in a show of glorious farmall pride.

If engine spins over good with starter see if the oil pressure goes up on gage. If not the camshaft is probably not turning with the drive gear. Compression check or removing valve cover to see if cam is opening and closing valves will also tell.

I will check the oil pressure thing but if it needs cam something or another should I fix it or sell it as is and move on to something newer? How much of a pain is changing a cam? I really like the m because i learned to drive a tractor on one and I just like it. And I've made it my own by now with a bunch of minor upgrades, but if it's going to be a big deal to fix this I will call it good and get something newer. I guess I'm saying I really like the tractor but if it's going to be an ongoing struggle to make it work with modern hay equipment I will just get something different. That being said I think the farmall and the newholland square baler have a little romance for each other because my square baler works smoother, eats bigger windrows, and shears less pins behind the farmall than the newer tractor hands down.

The cam drive gear is possibly broken at the cam (or teeth missing. if the valves/rocker arms are not in time with TDC that is
likely to be it. Jim

Never know what problem is unless checked out. But if keyway failed where drive gear goes on the camshaft or some teeth messed up? To remove camshaft front bolster and radiator comes off. Remove oil pan, oil pump, front crankshaft pulley, front engine cover, valve cover, rocker arm, push rods, right side cover on engine, camshaft followers raised up or removed then camshaft. Three bolts in hydraulic pump and governor bolts need removed before front cover comes off and at least one or two more (memory fail) goes into front cover from back of steel plate. Warning when you changed the hydraulic pump if a bolt to long was installed in the lower pump mounting hole block side it will contact camshaft drive gear and lead to damage. That's the one bolt that can be left in pump when removing the front cover. At the least you can find them with bolt wear on back of cam gear and bolt end wear with metal cuttings in engine if a bolt to long is installed.

Most likely added stress from the new hydraulic pump caused the cam drive gear hub to break. All the associated parts (camshaft, distributor, hyd pump) will still turn when the engine is cranked. But everything will be WAY of of time. Thus the engine's refusal to start.

I replaced a busted cam gear on my Super M, also on a 400 for a friend. Aside from having to remove the front bolster and radiator assembly (awkward and top heavy), and needing a 2-1/2" socket to remove the crank pulley, replacing a cam gear is not difficult. A new cam gear is less than $200.

Well I checked the oil pressure this morning and you're right, no pressure. I guess I will check around and see if I can find someone to fix it for me. Anyone near Grand Rapids, MI that you guys know of? Or anyone want a weekend project?

Also, if this is a common problem maybe I should get it fixed and then get a different tractor? I use the m for raking hay, pulling wagons, and baling occasionally. If it doesn't have a good enough or reliable hydro system it makes it pretty tough to rake hay with. I think my rake needs 2000 psi or so to lift it which is asking a lot from an M I suppose.

If the woodruff key sheared but only partially, the gear would still turn but the timing of the engine would be off and thus not start. I've never had my 400's pump apart so I'm not sure how these things are put together, I'm only mentioning the woodruff key because I have seen it happen on small engine flywheels. The Key would shear halfway and the flywheel would still turn but no spark.

Stage II Super Ms are good enough tractors that they rise above regular Ms in most cases. Value on selling it with a broken engine
will be 50% of the value if fixed. So if you are going to have it fixed by others, consider the differential in return on your
money. Selling it broken may be financially correct. If having it fixed, using a 450 cam and gear is the strong option as they
are different at the hub, and have a bit more power compared to the OEM cam. Jim

(quoted from post at 10:08:40 03/11/18) Stage II Super Ms are good enough tractors that they rise above regular Ms in most cases. Value on selling it with a broken engine
will be 50% of the value if fixed. So if you are going to have it fixed by others, consider the differential in return on your
money. Selling it broken may be financially correct. If having it fixed, using a 450 cam and gear is the strong option as they
are different at the hub, and have a bit more power compared to the OEM cam. Jim

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I thought my super m had the same cam as the newer ones? I checked the serial number as best I could with a post somewhere on here and I thought mine was the newer style anyways. So maybe it's a freak thing that this happened and I shouldn't expect it to ever happen again? But I'm Leary about that after hearing so many people with similar problems in the past. I really love a lot of things about the super m but good hydraulics are really a need for the stuff I want to do with it.

Serial number is F-22564 J if anyone could tell me for sure if that means the stronger gear was in it or not.

Something off F-22564 didn't come with a engine driven pump. What is the engine serial number?

(quoted from post at 17:19:45 03/11/18) Something off F-22564 didn't come with a engine driven pump. What is the engine serial number?

Click to expand...

No engine driven pump actually makes sense because the resivour on this tractor is in the belly where a pump would go otherwise. Maybe it had a belly pump oriiginally and someone along the way added a live pump. I'm not sure what numbers are the serial numbers on the engine but I see these numbers cast into the block

C-264
356980 RI
12 15 X

And this number stamped in by hand
27430

27430 is the engine serial number. Both it and tractor were assembled in Jan. 1953. So far I don't know the exact information on the cam gear change from 6760-D to 6760-DA. SM parts books Dated 5-5-52 show 6760-D and one dated 6-29-53 shows the same number. Parts books are not exact for that but sometimes give a general idea. Now you can't be sure parts found in the engines are what they started with. Pretty sure some SM tractors came with the 6760-DA gear but not sure about all. Latest gear IH used for replacing cam gear was 6760-DB started during 400 tractor production. Then during 450 production the cam nut and threads to retain the cam gear was changed to left hand threads. Helped with problem of nut getting loose holding cam gear that lead to keyway wear and other problems. Found a good bit of the right hand thread cams and nut still good though myself.
If the hydraulic valve doesn't have a pressure relief or other relief valve installed with the conversion that's one way to damage parts.

wow thanks so much for getting all that info! I will probably know soon enough if the cam and gear that are in it now are the old or new style once it's apart. I suppose either way it needs to get fixed so that's the road I'll take unless I find something catastrophic happened in there. Not sure if the pump has a relief built in or not, it's a new old stock pump that originally went on the supers and 400's or at least that's what I was told when I bought it. If the relief is in the valving then I defanitely don't have one because I tossed all the old stuff and ran a simple setup of belly tank to pump, pump to two way valve, valve to filter and then back to the tank. I could put a relief in there if I need to, I actually have one sitting around so it wouldn't be a big deal.

Depending on two way valve it may have a relief in it. If it's the type IH used on a SM it doesn't have one. Wouldn't set relief above 1500 PSI or a little lower if pressure isn't needed. If you need more than 1500 PSI you probably want another tractor.

The cam gear was already likely stressed from 65+ years of use, which is why it broke. A new cam gear will last another 65+ years, so I would just fix it and not worry about it.

It's not that big a deal to fix. The hardest part is getting the front end off the tractor. If you've got a decent size concrete pad to work on, preferably indoors, and a 2-ton cherry picker or another tractor with a loader, you can do it.