DWV

At one time I would of swore you are correct. Then a engineer old me I was wrong about the caster on a narrow front. He explained that they work more like a grocery cart front wheel when going forward. Not sure what to believe so just throwing this out. Do know the steering wedges were supposed to make steering easier. Caster angle was changed to less caster on the narrow fronts to make them easier starting during 1952. Lower bolsters with a casting suffix through DC are different from there through 450, they have a DD suffix. Tire size can affect caster, and I think the closest to vertical the caster is on a level hard surface the easier to steer. Other settings result in having to add a small effort more to lift front of tractor into effort. In use there is a lot of variables to steering effort. Most wedges had thin part marked to front.

Think if you have the steel main tank support instead of the cast the strainer was in starting tank. Things get complicated trying to figure out the early setups. Part of early fuel tanks used 1/4 inch pipe thread outlets before going to 3/8 pipe. Most of the early parts were no longer available after IH released change over parts. Even some replacement starting tanks had changes. Fire risk was reason strainer was moved to main tank. Other than what was mentioned I think corn picker fires were also part of reason for changes. If I remember correctly the outlet pipe to carburetor with strainer on small tank went through holes on the steel supports to carburetor. Could be thinking of a H. One winter in evenings I worked on figuring what parts were use and when and made several pages of notes in a large notebook. Luckily, I had early parts book that only showed one-part options unlike later parts books that take a bunch of figuring what was what and why. Over the years I tried to find every M parts book put out by IH and think I have most. But the early fuel parts and the changes are one of hardest things for me to figure up. Used to remember most everything when learned but memory way downhill now. Even after looking at notes should have made them better because having trouble remembering after looking.

Both work. some inner changes one being center armature support with bushing using four screws to retain on later starter. Two used before that.

Maybe some answers to questions in posts. IH started disc brakes on M serial number 294226 and MD 285505. First M built in Callender year 1952 was 290923. First one March 1952 was 295555. Last regular M was serial 298219. Band brake housings will use the late M and SM disc brakes in enough parts are changed. Owners of some SM tractors with broken housings replaced with band brake housings. when SM parts were used the differential carriers bolted to same holes it housing as band brakes used. Disc brake housings bolt to the differential carriers instead of transmission housing. Without a doner disc brake tractor you need to gather up several parts to put on a band brake M. Band actuating shaft and bolt holes can be seen after discs installed. Even though Disc started at a lower serial number for a MD than other fuels they were both built in February 1952. Can't remember now but the past a reason was given for MD production slow down near end.

Serial number is for a stage 2 SM. Some were still sold without the engine pump and unit under fuel tank and equipped with liftall in center housing. If built that way it should have a 3 bolt starter mount center housing, bracket on left side of rear fuel tank support with holes for starter operating rod, choke rod and belt pulley gear box operating rod if equipped. Are you going by date code, casting number and block serial number to ID engine? Probably not the case but you could have a replacement engine from IH with same year letter as a 42 M. If not ground off the casting number is 365586R1. That block was sold with all three sizes C-248, C-264 and C-281 on the blocks. No matter which size was on block all had the same bore size for sleeves as a SM through 450. Will have a plat near carburetor to block off a fuel pump opening.

503 is reported in red power magazine. Location Canada.

Made up a one half inch rod by bending a short 90 on end, then grind end thinner to drive out from top. Catch seal below bushing and alternate driving sides of seal. I use a long piece of 5/8 all thread with puck to fit seal. Drive in from bottom or use nuts and bar across top to pull in using the threads. Be sure seal starts straight.

Probably power to coil is not shutting off when switched to diesel. Manifold should have switch behind a cover with two studs for wire from switch and wire to coil. If switch quit working or it came with a magneto and change to distributor and they may have switch wire straight to coil. Could add a switch in wire to coil but need to remember to switch off after running on diesel.

Couldn't find a M. This SM is the same except for the M carburetor instructions in picture that SM didn't have. Left out some parts that are normal for a complete engine rebuild that IH suggested checking. May have pictures out of order.

Other than pistons, sleeves and rings a M kit contained a distributor rotor shaft to obtain a total of 22 degrees advance with pin for drive gear, set of springs. Carburetor parts, main seat and adjusting screw, Air bleed, idle jet and discharge nozzle. Depending on time period the instructions put out it was suggested the cam used in 400 and part of the 450 could be used for more power and also using the latest manifold like on a 450 at last. Also gave instructions on setting time. Don't remember any changes on a supper M other than using the 22 degrees rotor like above and same suggestions on cam and manifold. On 400 and 450 the distributor was left at 25 degrees and no other changes. On a M I remember a change on the main seat size for fire craters. Need to see If I can find the size change I noted someplace.

Late M still had the same speed gears as others. They did get a 12-inch clutch and non-greaseable pilot bearing flywheel. Input shaft housing with bigger front bearing on input shaft and bigger diameter main and rod bearing journals on crankshaft that SM used. Had two 52 M along the way and they were M speeds. What I remember is the input shaft parts started before 52.

Never used a 504, only bought a couple salvage ones for transmission parts to use in 300 and 350 tractors. Also heard they were gutless. Going by specs it doesn't add up that it can't do what a H will. Maybe not last as long. Both are around the same weight and close enough that either one could weigh more according how equipped. Farmall type rear tire size can be the same as a H. Gasoline is rated several horsepower higher than a H according to Nebraska tests. Both engines if original have the same bore and stroke. If they won't lug with a it must be the head, intake and exhaust design, or camshaft profile. I grew up on a dairy farm and big enough to use tractors in the middle fifties. At that time in my area a tractor with 50 HP was considered big. Anyway, my dad raised silage and hay to feed the cows. All planting and harvesting done with a 41 H gasoline model that was a little unusual built for gasoline at the time and a 56 Ferguson 40. Spent a lot of time on the H working corn ground, balling hay then on to Silage and manure hauling. Engine was rebuilt since new but they put the same type 3-3/8 cast iron pistons that it came with. It would lug for what it was but no powerhouse. With disc in bottom ground some places would sink full in it was sone lugging down to I could almost count the RPM. It would make it through most times though. More fun was 5th gear power, hit a grade pulling a baler nut long to fourth gear speed. Pickup a rough Farmall but a Stout engine with fire craters and was tickled to death with the difference. Picked up a later H with overbore fire craters and it was better than previous H. M spoiled me from using those if serious work was involved. Hard for me to believe a 504 Farmall with a T/A wouldn't out due that original H. It was a runner that kept going though. Picked up other tractors on up but a 560 was the newest.

Transmission is close to a 460 after IH changed them to updated parts. Row crop came with 2-3/4 axles. Also think a 504 could be had with a engine driven hydraulic pump or in center housing. Ring and pinion has a deep reduction compared to previous rears that size. One optional first gear was a deeper reduction. From what I remember 3 first gear ratio could be used except one was only used in shuttle sift tractors. IH turned the RPM up and used gearing to get more power to ground. Do you have diesel or gas? Most speed gears in transmission will interchange with a 300 on up to 460.

Lots more could be said on this subject, hoping not to long of post. Stage one SM tractors were like the last M tractors except for badging, 264 engine and different gear speeds in 2 through 4 and reverse. Stage 2 SM received cassis changes for a engine driven hydraulic pump. Some still were equipped with a liftall unit in the center housing but other stage 2 changes stayed. Had a stage 2 gas and diesel with belly unit built at Farmall works. One from Louisville seem to be more common. Ones with belly pump have different brackets mounted to rear tank support for control rods. Starting 2 the center housings were changed to 3 bolt starter mounting and used on both gas and diesel SM and SW-6 with frame rails. Housing placed starter opening the same distance from fly wheel gear. Before stage 2 Diesel 3 bolt starters were a different distance ang gas were 2 bolt starter mount. stage 2 housings have bosses on left side, some bosses are drilled and tapped for use on SW-6. (Picture) No SM were equipped with live or IPTO from IH. Supper MTA used transmission housing like the 400 and 450 that followed with a stage 2 SM top cover with special shift forks that were only used on SMTA and SW6TA. Center housing 5 inches longer than a SM. SMTA transmission housing Had mounting bosses at rear on sides used for fast hitch mounting on 400 and 450. No SMTA came equipped with a fast hitch. Can be mounted but with standard liftall only could be raised and gravity lowered unless equipped with remote control valve. First type fast hitch used on 400 tractors have parts that don't bolt up on a SMTA top cover, also uses 2 hydraulic cylinders that need two control valves. (picture) Second type fast hitch is easiest to mount on SMTA. Aftermarket and others have come up with ways to mount a fast hitch on M and SM tractors though. SMTA could be equipped with IPTO and T/A, IPTO and no T/A, T/A and transmission driven PTO. Bare bones just had a straight shaft from clutch to transmission input shaft and a counter shaft with splines for PTO drive like M or SM. Few didn't come with hydraulics. Can ID by the rear tank support only used on them to reach the tank that's five inches forward from a M and SM. One picture is for a stage 2 SM front counter shaft cover used on stage 2 with engine driven hydraulics. No seal needed.

358040R11, gasoline serials 501 to 19233.