Traction New Jinma 354 owner-differential lock question

[gergstuff]

Hello!

I just bought a 2006 Jinma 354 with only 30 hours on it.

My question relates to the differential lock. There is a small foot pedal to the right of the drivers seat and I cannot tell if it is engaged or disengaged. The pedal has very little upward travel-perhaps an inch? I can't seem to get it to do anything by stepping on it or trying to lift it up.

The prior owner I belive may have been operating it with the differential locked for all 30 hours of use.

When I test drove it on dirt it seemed to be fine (I was not aware of the diff lock at that time).

When I drove it on pavment I thought I heard some clunking from the back end.

Do you step on this pedal to engage and disengage?

What harm has been done to the differential if indeed it has been locked it's entire life?

Has my "bargain" turned into an expensive life lesson?

Thank you for any input offered.

Craig

 

[bh3zfc]

You do step on it to engage but you will not be able to tell if it is engaged if the tractor is not spinning the other tire. If you have a box blade or other implement hook it up and when you start spinning press the pedal.

 

[Rich Waugh]

The differential lock should not stay engaged once the clutch is depressed and power is no longer being sent tot he driving wheels. The diff lock operates by dogs that drop into place when you step down on the pedal and let out the clutch, similar to the way a Lovejoy joint couples together - you should feel a little "chunk" when the dogs drop into place and the rear differential will now be locked and the two wheels will turn together. When you press the clutch again and allow the tractor to stop moving, the dogs will jump back out of engagement and you'll have differential rear wheel action once again. You do not need to lift the diff lock pedal; it will happen by itself. I see no way the diff lock could stay engaged beyond what is normal.

You can easily test the function of the diff lock if you have some soft soil where you can get the rear wheels to spin under load. Also, if you split the brake pedals and hold one brake while turning hard in that direction you should feel the differential shift all power to the outside (unbraked) wheel. If you engage the diff lock, stepping on one brake will cause both rear wheels to slow down momentarily, until the diff lock disengages itself.

 

[gergstuff]

I suddenly feel much better!

I was thinking if the pedal was depressed it would stay locked until you stepped on it again to disengage.

Thank you!

Now I can spend my money on implements instead of a costly repair!

Craig

 

[RonMar]

No, it should only stay engaged while the pedal is down. Mine is activated by a lever on my 284. It dosn't pop out when I step on the clutch. As it couples the two axles together I don't think the clutch really comes into it. I usually have to roll a little bit and shift the steering left or right to unload the pawls and let the spring pull them apart. On mine the lever pushes a plunger. When I am done with the difflock, I pull the lever back up to the disengaged position and hold it there with my leg. If I do not hold it, it will just fall back to the engaged position as it is the plunger that holds the lever up. When it disengages I can feel the plunger smack the end of the lever thru my leg, then I can move my leg and the lever stays up.

If the pedal pushes on a plunger, sometimes that plunger gets sticky and won't allow it to pop out. With the difflock engaged, it is pretty hard to steer as the two rear wheels now have no diff between them and only want to rotate at the same speed.

One way to check it's health is to jack up the rear end and get at least one wheel in the air. With the transmission in neutral and 4X4 not engaged, you should be able to rotate one rear wheel if it is in the air. Once you step on the difflock, it should couple the two rear wheels together and you will no longer be able to rotate the airborne wheel.

 

[greg_g]

Pretty sure the JM354 diff lock is pedal operated Ron. As Rich describes, it's a simple matter of stepping once on the pedal to engage. No need to hold your foot on the pedal, as long as the driveline is turning. Subsequently, throttling down and/or pushing in the clutch pedal removes driveline tension from the diff lock dogs - which permits their return springs to separate them.

//greg//

 

[RonMar]

Yea Greg it is pedal operated, but I am pretty sure that pedal pushes in on a plunger in the side of the case...

 

[traktorz]

Differential lock broken on our Foton FT404 tractor

Well, at least you're lucky to have a differential lock on your tractor.

Ours are gone, some time back. It's possible to be without one, but sometimes I wish we still had it.


Ref:
Differential lock broken on Foton FT404-2009
http://www.tractorbynet.com/forums/chinese-tractors/260847-differential-lock-broken-foton-ft404.html

 

[zonta223]

Re: Differential lock broken on our Foton FT404 tractor

Did you ever find out the details how to strip this out?
Do you have the Foton manual on CD which has movies showing the Diff assembly repair etc. Has a clear picture of diff lock on the crown wheel assembly?

Well, at least you're lucky to have a differential lock on your tractor.

Ours are gone, some time back. It's possible to be without one, but sometimes I wish we still had it.


Ref:
Differential lock broken on Foton FT404-2009
http://www.tractorbynet.com/forums/chinese-tractors/260847-differential-lock-broken-foton-ft404.html

 

[traktorz]

Re: Differential lock broken on our Foton FT404 tractor

Did you ever find out the details how to strip this out?
Do you have the Foton manual on CD which has movies showing the Diff assembly repair etc. Has a clear picture of diff lock on the crown wheel assembly?

- No, I haven't investigated further the route to repair the diff lock.
- No, I don't have the CD version of the manual, only the books that came with our tractor.
- I would like to get hold of that CD manual, looking for ideas of repair workflow. Maybe somebody has a dropbox link to share?