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D-8r641 Gearbox

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16 years 10 months ago #10521 by HUNTER
D-8r641 Gearbox was created by HUNTER
Help!. I seem to have lost the use of some gears recently.I have 1,2,4,6,and reverse low,but I no longer have 3,5,,and reverse high. If I select any of the gears that do not work,when I engage the clutch,there is no movement.Also,when I select the gears that do work,they stay engaged for a period of time that seems related to the amount of load placed on them(the more load,the quicker they pop out).They will pop out of gear,sometimes,not all of the time.Any ideas what may be going on and how to fix them?.

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16 years 10 months ago #10527 by Old Magnet
Replied by Old Magnet on topic D-8r641 Gearbox
The gears not working share the same sliding double gear on the rear of the pinion shaft. Either there is a shifter fork problem or possibly a gear problem. Gears should not pop out if the interlock mechanism is adjusted and working properly and the main clutch is in the engaged position.

Also be aware that the early models did not have a shift gate lock so be sure you are only moving the required shifter fork.

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16 years 10 months ago #10539 by HUNTER
Replied by HUNTER on topic D-8r641 Gearbox
Would re-timing the interlock help?.

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16 years 10 months ago #10540 by JC 4T
Replied by JC 4T on topic D-8r641 Gearbox
Mine has gears that don't work that don't have any sliding gears or shafts or bearings in common. I am going to check to see if the slide bar is timed, but I haven't had the time yet.

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16 years 10 months ago #10543 by Old Magnet
Replied by Old Magnet on topic D-8r641 Gearbox
Not likely the interlock would be out of time unless you had it apart. You can check the timing by inserting a punch in the plug hole on the side of the case and see if it picks up the cam position. It is the arm with the cam that controls the slider gear that is suspect here.

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16 years 10 months ago #10606 by HUNTER
Replied by HUNTER on topic D-8r641 Gearbox
I went out Sunday morning to fire up and tinker with the timing and the interlock a little bit,and to my suprise,the missing gears were back in operation,and they stayed in gear. I did nothing to the gearbox at all,and I disked about 30 acres that day with no problems at all. Miracles can happen. Thanks for your ideas,now I know where to go if it happens again.

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16 years 10 months ago #10607 by HUNTER
Replied by HUNTER on topic D-8r641 Gearbox
Would I be able to put a shift gate lock on this machine,provided I could find one??

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16 years 10 months ago #10615 by Old Magnet
Replied by Old Magnet on topic D-8r641 Gearbox
Yes you can but it will take a sr. #9045 or up to get the parts which include a different sector, the lock and main support bracket.

Miracles do happen:D :D
Must have just been sticky shift gates.

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