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8400 Gearco Transmission

Marino77 · 2019-03-10 13:57

Good day Folks Hopefully I can get some answers here new to the site .. story goes .. purchased an 86 740 Champion grader.. Invested a fair amount so far.. new main pump/ slave cylinder / clutch as for pressures they are all up to spec however seems the transmission slips.. placing the mould board down machine doesn't want to move let alone cut .. I figure it may be the clutches in the transmission where does a guy start .. Gearco 8400 (29781-720 )Transmission .. Seeing what's is out there as for a rebuild ..located in B.C trying to save a few dollars re and re are not cheap ... Thank You

Replies7
  1. #1Welder Dave2019-03-10 20:44

    They might be a little pricey but are the Champion experts and not too far away in Alberta. http://www.jadeequipment.com/

  2. #2Fatgraderman2019-03-12 20:25

    Is it like that in every gear? Just certain ones?

  3. #3Marino772019-03-13 01:16

    1st travels ..doesn't cut w blade down hardly 2nd travels but same as above 3rd travels 4th gear nothing .. Reverse Gears 1 st moves that's about it for climbing up a slight hill forget it 2nd nothing got to be pinned to get some movement backing up .. Fyi ..all current work in above post was just done at a shop ..

  4. #4DB22019-03-13 08:40

    Does the drive shaft between the engine clutch and transmission remain spinning?

  5. #5Fatgraderman2019-03-13 15:48

    ☝️☝️ start there. After that, there is a housing higher up on the front of the transmission. Collector housing (I think) and when it get’s worn, it can do similar issues. When a clutch inside the transmission goes out, you’ll lose groups of gears. For instance 1 + 2, 5 + 6, and 1+3 reverse or 5-8 and 3,4 reverse. You get the idea.

  6. #6Geordie2020-01-05 00:06

    from the way you describe it I would get 3 pressure gauges and re check the pressure gauges and re check shaft pressures. The collector caps on the end of the shafts have 3 of 1/8 pipe plugs. The centre plug is lube pressure and the inside plug and outside plug are lock up pressure test ports. The shafts have 3 hook type rings on the end of shaft . These are to keep the pressures separate. If the piston ring hooks break or wear off the oil crosses over putting that shaft in a hydraulic induced neutral as it is trying to lock both clutches at same time thus giving you a neutral. But the way you are describing it I would put money on the engine clutch is out of adjustment. There was same manuals printed that stated measure clutch clearance in the cab which is wrong. Part get worn and the release bearing is way out of adjustment not letting the clutch to release fully. The leaver at clutch housing on right side (Everything is taken when sitting in the operators seat) of bell housing should have 1/2 inch of clearance to get the you might not have any clearance at the cab.

  7. #7Chillin' Champion2023-01-03 08:22

    How'd you make out on this one Marino77? I'm in BC also and having issues with reverse. Did you end up rebuilding your trans?