Diff lock not working.

[clemsonfor]

The last few times I have tried to use the dif lock it's not working, it will slightly go down but kind of springy but not go to the floor board. I can't tell if it's stuck engaged but I think it might be, j just started thinking this was the case recently and not paid it much attention, j need to see if I can do something to doing both tires, maybe put it against a tree and ease off the clutch in low gear.

Last I remember it working when I stepped on it was probably a year or more ago, but I just use it when I need it and don't pay much attention.

I assume I need to pull the top off the transmission and have a look at it.

Any thoughts?
@California I know you have been into this before do you have any pics down in there for me to look at before I pull the top off? I know you said the fork on yours was worn not letting it lock in.

I have had the three point top off a few times so that's no big deal other than it's heavy and awkward the way it needs to be lifted off.

 

[2manyrocks]

If the differential is locked, both rear wheels will turn and it will be hard to steer left or right. I'd start with the most simple thing which would be to lubricate the engagement just to be sure it isn't binding from rust or dirt, etc.

 

[ruffdog]

It might just be that the shaft going into the case (from the lever)is rusted and is not moving like it should. Lube it up where it goes into the case and get it moving.

 

[clemsonfor]

If the differential is locked, both rear wheels will turn and it will be hard to steer left or right. I'd start with the most simple thing which would be to lubricate the engagement just to be sure it isn't binding from rust or dirt, etc.

Right I forgot about that. It steers left or right as normal.

 

[clemsonfor]

I will spray the spot where it enters the case, but it pivots down and up a little bit just won't go all the way down to the floorboard like it does when it engages.

 

[2manyrocks]

After your lubricate, I'd try shifting through all the gears including reverse just to see if it loosens anything else up that might be stuck. If it doesn't feel like it's going to engage, don't force it.

 

[clemsonfor]

In the last few months I have shifted through most of the gears, not since I lined obviously. I have prepped the garden with it and used all the gears on the high range and I believe not that long ago I used a few on the low side at least.

 

[IndyIan]

Is your tractor HST with wet brakes? Mine is and I figure I will never wear the brakes out normally, so I just drag the brakes abit if I need some "diff lock" if I'm in low range doing dirt work in the mud... A trick until you get yours fixed anyways.

 

[sandman2234]

Step on the diff lever and keep pressure on it, then turn the steering wheel and start going around in a circle. The change in radius of the two tires will allow the gears to line up so that both sides will engage, as one side may not be letting it engage. Worth a try...
David from jax

 

[clemsonfor]

Is your tractor HST with wet brakes? Mine is and I figure I will never wear the brakes out normally, so I just drag the brakes abit if I need some "diff lock" if I'm in low range doing dirt work in the mud... A trick until you get yours fixed anyways.

No. It's not wet brakes. There in a sealed compartment, if there wet for any reason you have a serious problem!

 

[hube2]

Could it be that you're just not getting the slots in the diff lined up for the pin to go in? There is only one slot in each side of the diff and you might need to let the spinning tire turn up to 180 degrees before they line up.

 

[California]

@California I know you have been into this before do you have any pics down in there for me to look at before I pull the top off? I know you said the fork on yours was worn not letting it lock in.

The previous YM186D needed some welding to build back up the 'ramp' that a pin climbs, when you step on the pedal. Photo and diagram where I responded are in this old thread. Part #12 is what was worn:

Trans case lock seem not to work anymore

A few months ago It worked great when I had to cross one of my creeks, today, I had one wheel slipping and stomped the pedal, and it did not engage. I have not gone to the manual yet, and it was getting dark, the pedal stayed down and had to pull it up with my heel. Any thoughts? This is on a 186D

www.tractorbynet.com

But I suspect your problem might be that the fork can't slide along its shaft due to crud or rust.

I don't have any photos looking down into a Yanmar transmission. Here's the thread you might be thinking of, showing the PTO assembly removed from my YM240 (YM2000) but this doesn't show the view from the top, that you need.

Because these rice tractors are designed to run half submerged, there is an o-ring sealing where the pedal shaft enters the transmission housing. So lubing the exterior there isn't likely to help.

Just thinking about it - I think the shaft from the diff-lock pedal goes clear across the YM2000 transmission and does something on the far side too. Check this.

Good luck with this project, and we would love to see photos!

 

[California]

Step on the diff lever and keep pressure on it, then turn the steering wheel and start going around in a circle. The change in radius of the two tires will allow the gears to line up so that both sides will engage

Similar advice in an old Wagoneer owner manual: When you can't get it out of 4wd, back up in a zigzag pattern while pulling on the shifter.

 

[winston1]

Pictures in this thread might help you. broken PTO

 

[clemsonfor]

I hate I didn't realize or have this on my radar last year when I had the whole PTO unit out and bull gear and axle out of the left side. Looking up in there I might of been able to see something.

I may have to look back through my pics I took several last year while in there for future reference and stuff. When I pulled the top off I think that might of been pre smart phone era for me and pics weren't as common then and it would take me longer to find them if they actually exist than pulling the top off the trans itself! . I might need to find my thread when I rebuilt the three point, where I did the piston and valve to see if I took any, I know I posted some to that thread.

 

[clemsonfor]

Because these rice tractors are designed to run half submerged, there is an o-ring sealing where the pedal shaft enters the transmission housing. So lubing the exterior there isn't likely to help.

Just thinking about it - I think the shaft from the diff-lock pedal goes clear across the YM2000 transmission and does something on the far side too. Check this.

Good luck with this project, and we would love to see photos!

Your thinking about the o ring is the same as mine. If it's free which mine is it's sealed so it's not doing anything by spraying it.

And yes it does run over to the far side I was thinking it's just to clear a gear or something and where the slave that locks them just happens to be on the far side. I was looking at the parts diagram on Hoye last week and was trying to follow it without being able to look inside at the time I was kind of lost.

 

[clemsonfor]

Similar advice in an old Wagoneer owner manual: When you can't get it out of 4wd, back up in a zigzag pattern while pulling on the shifter.

I have an old school k10 with the NP205 transfer case. Yes that's the holy grail one that all the off road guys want. It's the all gear driven one. Sometimes you can't get it out of 4wd and to get it to come out of 4hi I let off the break to start creeping forward and it pops right out.

 

[clemsonfor]

All of this worry was for nothing. I hope out there and back out of my shed and put it in second gear to try and test the diff lock step in it, it locks in and about sends me through the fence as I couldn't turn. Slowed down and took my foot off it and stopped backed up an bit and then drove forward where I had room to turn. To confirm it, I stepped on it again and it went right into lock after the rotation or whatever. Not sure why I couldn't get it to go in before? Maybe I didn't stand on it long enough? Oh well. It's working is all that matters to me!

 

[California]

Good to hear you got it fixed.


That rollpin between the shaft and the ramp seems pretty lightweight. I wouldn't ever 'stand' on the difflock pedal. Just holding it down snugly is sufficient to make it engage after a tire slips allowing the cogs to line up.

 

[clemsonfor]

Good to hear you got it fixed.


That rollpin between the shaft and the ramp seems pretty lightweight. I wouldn't ever 'stand' on the difflock pedal. Just holding it down snugly is sufficient to make it engage after a tire slips allowing the cogs to line up.

Well stand on it is probably overstating the force I was actually applying to the lever. For sure I wasn't actually standing on it with all my weight. Sometimes applying more force than others , but far from putting all 200lbs on it!!