LOSS OF 4X4

MISSION JOE · Feb 4, 2014

I HAVE A 2010 JINMA 404. A FEW TIMES THE MACHINE HAS COME OUT OF FOUR WHEEL DRIVE . THE ACTUAL LEVER MOVES . SEEMS TO HAPPEN WHEN I PUNCH THE THROTTLE WHITH THE FOOT CONTROL , AHEAD OF A NASTY MUD HOLE ON THE ROAD. THE REAR WHEEL MAY HAVE SOME SPIN WHEN THIS HAPPENS. THEN I JUST MOVE LEVER AND POWER THROUGH,WHITH LESS THROTTLE.COULD IT BE TELLIN ME TO GO A LITTLE EASIER ?

greg_g · Feb 5, 2014

What you describe sounds backwards. Torque holds the lever in place when the governor is pulling, but disappears when the governor backs off. Hence torque on the lever holds it in gear when pulling, and vibration makes it jump out of gear in the absence of torque. But this is something that happens to old tractors with worn gear faces. Yours is quite young, and doing the opposite - and should not be happening. I'm guessing that you have damage in the bottom of the transmission where the sliding drive gear drives the transfer case driven gear. Might be as simple as a broken gear tooth.

First thing I'd do is drain the tranny, drop the front driveshaft, remove the transfer case. Inspect the drive and driven gears for damage. Also make sure that the shafts upon which these two gears turn aren't loose in their bearings.

//greg//

MISSION JOE · Feb 5, 2014

I RECENTLY HAD THE CLUTCH DONE , SO I HAD THE ENTIRE TRANSMISSION INSPECTED. ALL SEEMED WELL AT THAT TIME. I HOPE NOTHING WAS MISSED. MAYBE ITS SLIPPING OUTBY ME LETTING OFF ON THE THROTTLE WHILE BOGGING DOWN IN THESE LARGE MUD HOLES. I WILL TRY NOT TO USE FOOT CONTROL, AND JUST KEEP THE TROTTLE AT A CONSTANT R.P.M. , RATHER NOT START PULLING THINGS APART YET , IF POSSIBLE .

greg_g · Feb 5, 2014

Who did the clutch work? You should not have to compensate by changing what is ordinarily normal operating procedures. No reason not to be able to stomp on the foot pedal to get that last ounce of governor range when pulling uphill. If you feel you're going too fast downhill, just pull back on the "throttle" lever. If that doesn't work, there is a possibility that an incorrect clutchpack alignment is responsible.

//greg//

MISSION JOE · Feb 5, 2014

HEY GREG , SEEING AS THE CLUTCH WAS GONE ON THIS TRACTOR WHEN I BOUGHT IT(ONLY 100 HOURS) COULD THE GEAR FACES BE SOMEWHAT WORN ? MACHINE WORKS GREAT . OTHER THAN IT COMING OUT OF 4X4 COUPLE OF TIMES IN SOME WHAT EXSTREME CONDITIONS.. THANX JOE...

greg_g · Feb 6, 2014

Worn clutch is unrelated to worn gears. So with only 100 hours, it's highly unlikely gear faces are worn to the point where it won't stay in gear. Still need to know who did the clutch work, though. Too many owners - or the mechanics who profess to be "qualified" - make the mistake of assuming a Chinese clutchpack is ready to bolt on right out of the box. There are critical pre- and post-installation adjustments to verify/correct before putting the tractor back together. Too many of these "straight out of the box" clutch installations have very short lifespans.

//greg//

MISSION JOE · Feb 6, 2014

THE CLUTCH WAS DONE BY A DEALERSHIP WHO DEALS IN NEW AND USED TRACTORS. THE CLUTCH SEEMS TO WORK GOOD. TRANSMISSION IS STAYING IN GEAR , BUT WENT FROM 4WHEEL TO 2WHEEL COUPLE OF TIMES. (ALSO THINK IT CAME OUT ONCE FROM A BRANCH CATCHING THE LEVER FROM UNDER-NEATH)

greg_g · Feb 6, 2014

Yeah, but I noticed you didn't specify new and used Chinese tractors. Jinma two stage clutches may be outside their experience level. They're engineered completely different than Ford/John Deere/etc. If that clutchpack was not set up properly prior to installing, then not adjusted correctly after putting the tractor back together, you're pretty much guaranteed to have problems. I don't know what they did, so I don't know where to start. A good guess might be that they took it outa the box, bolted it to the flywheel, then put the tractor back together and hoped for the best. I don't doubt you're now suffering from that lack of Jinma experience.

//greg//

erj · Feb 6, 2014

Greg,
I want to improve my knowledge of transmissions, etc. What was the transition that took this thread from a 4x4 lever periodically disengaging to questions about the clutch. I am not understanding the relationship.

Joe,
Please turn off the Caps Lk on your keyboard.

MISSION JOE · Feb 6, 2014

May b i"m missing something as well. I didnt think the clutch had any thing to do with the lever poppin out , But i"m far from being a mechanic. I welcome any advice. Thanx to all , JOE...