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Ring gear for flywheel

Manny machineguy · 2021-07-16 23:52

I've been searching for the ring gear for the flywheel of my Allis Chalmers 645 for over a month now .... and still no results. Would anybody out there have one or know how to find one? Ring gear part# is 4350235-0 (93 teeth) Flywheel part# is 4025765-1 Engine is a Allis Chalmers 3500 I would also be open to the option of putting a different ring gear (with different teeth count) that would fit on that flywheel and change the gear on the starter. How would I go about matching that up? Any other ideas on how to solve that problem?

Replies15
  1. #1Tinkerer2021-07-17 09:56

    Sometimes you cannot just change a gear on a starter to a different size. Doing so can change the geometry of the starter gear to the ring-gear. In other words the center line distance between the two gears changes. If the distance shortens, a lot of stress is placed on the starter gear and the nose it is mounted in. I found the broken off ends of two armatures in the bottom of a torque convertor housing on a tractor I was working on. Some dummy had installed the wrong gear on the starter and that was the result. I knew something was wrong because the starter strained hard when starting the engine.

  2. #256wrench2021-07-17 10:05

    Check with an AGCO farm equipment dealer. Some ag tractors used a 3500 series engine i believe.

  3. #3Jonas3022021-07-17 10:57

    Minnpar may have some leads Did they use the same 3500 engine in some tractors and gleaner combines ? Any chance of flipping the ring gear over I have done that when the damage wasn't complete

  4. #4Manny machineguy2021-07-21 23:35

    Thanks for bringing that to my attention. I can totally understand how that could be an issue

  5. #5Manny machineguy2021-07-21 23:38

    I have checked with a number of them Agco doesn't carry them anymore

  6. #6Manny machineguy2021-07-22 00:05

    I will check with Minnpar tomorrow Yes lots of AC tractors had the 3500. The gleaner L series had it too. But they have different flywheels because they have a manual transmission. The AC 645 has a torque converter with a flex plate. The engine we're putting in is out of a Gleaner L2 but the flywheel is an inch larger in diameter, does not fit in the bell housing, would be too thick even if it did fit, starter is in the wrong place and has a wrong bolt pattern I have thought about flipping the ring gear. I have equal amounts of people that tell me to do it as I have that tell me not to do it. I'm attaching some pictures so you can see a bit of the damage. There are grooves to help it engage on the starter side but not on the backside. Will it still work?

  7. #7Tinkerer2021-07-22 08:04

    A lot of ring-gears have straight cut teeth. Yours looks nasty in that one spot. It should be turned over before it completely fails in the section where the teeth are badly damaged. IMHO.

  8. #8Mike852021-07-22 11:12

    Those look like wear from the starter. It looks fine to flip but check the starter pinion over

  9. #9repowerguy2021-07-22 12:03

    I have flipped a ring gear over in a pinch while positioning the bad spot to a different place on the flywheel. I also took a slicer wheel on a die grinder and put a relief chamfer on the teeth for the starter pinion engagement. Sometimes poor people have poor ways.

  10. #10heymccall2021-07-22 14:48

    93 teeth https://www.yesterdaystractors.com/70233305_Flywheel-Ring-Gear_31225.htm

  11. #11Vetech632021-07-22 20:12

    I swear, you can find anything! LOL I'm in need of a big breasted bed thrasher. Can you help?

  12. #12heymccall2021-07-22 20:17

    Just understand, that listing doesn't say "Allis Chalmers 3500", it says "up to 3500 ser no". Nor does it have the above part numbers. But, shirley you could get dimensions before buying

  13. #131693TA2021-07-22 20:49

    I work at a family owned dealership whom were a former Allis-Chalmers dealer from 1949 till modern day AGCO. There are none of these ring gears left in the system and they checked many NOS, and NS1 supply dealers for me today. That is not saying "Steiner", nor "A&I" might not have one, but we didn't research them.

  14. #14Manny machineguy2021-07-22 23:56

    I doubt that's the same one but I'll definitely check. The D14 has 30 hp and the one the 645 wheel loader hs 150 hp

  15. #15Tags2021-07-23 07:18

    You better be careful what you wish for, I have no doubt he can and will find that for you. I imagine it would be very expensive just for that particular “part” but it will probably cost even more when wifey finds out what you “ordered”…