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case 1840 drive motor differences i bought the wrong ones dohh

paulioq ยท 2026-09-04 20:05

hello as stated in the title i have got the wrong motors for my case skidsteer. takeing a chance i bought some motors of ebay thinking i had checked correctly in the parts catalogue but when trying to fit them i found the flange face bolt pcd to be alot smaller and have determined i have the late model motors 230459a1 and i need the early mole motors the 231815a1 doh has any one swapped these over befor and if so how did you go about it. the cost of one of the early model motors is more then twice the cost of the late model motors so i am interested to know if any one has fit them and how. i believe the hydraulic flow will be fine but the bolt pattern is different. i can only think i need to replace the weld on a plate with one that has the correct bolt pattern cnc in it for the late model motor. bit of a welding job but doable. just thought id see if any one had any suggestions i could sell them but i already have them and things like this are expensive in austrailia the customs and shipping is a killer. i see in the states can get them ok but not here.

Replies8
  1. #1Welder Dave2026-09-04 23:33

    I would make doubly sure that everything other than the mounting flange is identical. If you know the displacement of each motor would also tell if they are interchangeable. Cutting off the mounting flange and/or welding a different one on poses a big problem. It could cook all the seals and possible cause other damage to the motor. Might be possible if the motor was disassembled but that might require an experienced shop to take them apart and re-assemble them.

  2. #2donkey doctor2026-09-04 23:55

    Any way to drill new mounting holes d.d.

  3. #3paulioq2026-09-06 02:10

    i would be cutting the mounting flange of the skidsteer not the hydraulic motor. the late model motor i bought has a smaller bolt pattern then the early model motors that are in there. the part number says they are for this skid steer just a newer model these machines were on the market for 12+ years i can understand that parts may be different i just got caught out by this one. i have checked splines and dimensions on shaft for the offset from the motor face, thats all same for same. just have to get new steel mounting plates with the new bolt pattern to replace the old mounting plate. easy

  4. #4Welder Dave2026-09-06 17:11

    If the motors are different the pumps could be different as well. You need to check the motors have the same specs. such as the displacement and working pressure. If they're different the machine might not work very well.

  5. #5paulioq2026-09-07 22:54

    all the pumps are 45.88 cc theres 3 models of those, guess you need them side by side to compare to know what other difference there is. im going to do it and put up some photos up when i do i think that machine is antiquated enough to start having some open heart surgery done on it. eww ansewer from ai, it came up in my search windows but it confirmed what i suspected. Yes, the CC displacement and hydraulic flow are functionally the same. Both the early-style motor ( 231815A1 ) and the late-style motor ( 230459A1 ) share a standard 240 cc/rev displacement. [ 1 , 2 , 3 ] Because they operate on the exact same Case 1840 dual piston pump system, they handle identical fluid dynamics: [ 1 ] System Flow: Both receive a maximum input flow of 15.30 GPM (57.91 LPM) from the hydrostatic pump. Machine Performance: Because the cc displacement is the same, swapping between them (assuming you have the right serial number frame) will not change your ground speed, torque, or how fast the wheels spin. [ 1 ] Why they won't interchange Even though the "hydraulic math" inside the motors is identical, you cannot physical substitute one for the other . Case changed suppliers and upgraded the frame style halfway through production. The late-model 230459A1 utilizes a physically larger frame (similar to a Danfoss OMT series) which features completely different mounting bolt alignments and line port orientations compared to the early-style unit. [ 1 , 2 , 3 ] If you try to run one of each on opposite sides of the machine, the machine will track straight (because the displacement matches), but you won't be able to physically bolt the incorrect one to the chain tank housing. Are you replacing just one motor right now, or are you looking to replace both sides at the same time?

  6. #6Welder Dave2026-09-11 16:04

    That's good info. You should be able to adopt the newer motors but I don't know how easy or hard it will be. Probably have to pull the engine and pumps and completely strip the machine down. Good luck!

  7. #7paulioq2026-09-13 00:27

    i had to pull the pump to have the room to sit in there and grind out the weld on old mounting plates. just waiting for the new plates to be cut and drilled on a mill for the new mounting but should be ready this week some time putting it back together next weekend. ill have photos of that just nothing to look at, at the moment. grinding out old welds isn't much fun to see

  8. #8Welder Dave2026-09-13 15:55

    Yes, some welds are a pain to grind out. If the different motor mounts are just welded on and the rest of the frame is all the same makes for an easier swap. Just have to spend the time to line everything up perfectly and make sure the mounts are flat against the frame. Don't want the motors on a slight angle. Get a qualified welder to do the welding if you don't have much experience.