differential lock Yanmar 1300

kmosabe · Dec 2, 2006

I have a Yanmar 1300, was doing some snow removal with the blade. The left rear wheel was spinning, I hit the differential lock and the left wheel still spun. I thought this would lock the spinning wheel. I know these things get stuck, have not investigated this yet. Also from prior threads, I noticed these things seem to appear not to be activated when you step on them. When I step on mine, it appears not to move much. Is it only activated while you step on it and then upon letting off of it, is is deactivated? Little tractor did a good job, was my first major use of the tractor clearing the driveway; also spent an hour pulling kids tube around. Thing is not 4WD but yet never got stuck.

Ductape · Dec 3, 2006

I'm going to take a guess and say your diff-lock didn't engage because you stepped on the pedal WHILE one wheel was spinning. Try again, but next time push in the clutch, or otherwise stop the left wheel from spinning.... THEN try engaging the diff-lock. Pretty much as you suspected otherwise, when you let up on the pedal, it should unlock once the wheels are free to differentiate.

BruceR · Dec 3, 2006

Good idea to also keep it going in a straight line while the lock is engaged. You can take your foot off the pedal and it will stay engaged as long as there is pressure on it. You can see the pedal pop back up when it releases.

Bruce

LMTC · Dec 3, 2006

If the pedal went down and it did not engage, it's likely damaged. It's not designed to be activated while a wheel is spinnning. You may have trashed the gear that engages it by doing so....we've seen that done. If so, besides finding the parts, there is a day's labor in the tear down and repair.

kmosabe · Dec 3, 2006

RULE OF THUMB: DON'T assume you know everything. By the grace of the Yanmar Tractor GODS, there was a reason the pedal was stuck, because I did not know EXACTLY how this operated. Being, stuck, it would not engage. I used some WD 40, got it unstock, took it out on the ice and activated it like I should have. All worked. Thanks for the great advice, love this site.

kenmac · Dec 3, 2006

glad to see you figured it out & got it working.

Ductape · Dec 3, 2006

Yep.... now its a two wheel peel mobile !

Cord · Dec 4, 2006

Mine too was stuck when I got the tractor. It did take some time for the lever to really free up. The lever needs to spring back on it's own, so keep lubing and working it by hand until it's free. When you engage the diff lock, it does take a moment for it to engage. There is some initial travel while the slack is taken up. If you are going straight ahead, it will take some wheel slippage for the mechanism to align. Once aligned the pedal will drop to the floor plate. You need to keep pressure on it or the pedal will release once the pressure is off the gears. After a while, you'll see when you need to step on the pedal again to keep it locked. Generally I try to anticipate the need for the diff lock and engage it before actually need the feature. Don't forget that it can be hard to steer with the diff locked. 4wd definetly helps to pull the tractor around. You can also use the wheel brakes to help steer the tractor.

tallyho8 · Dec 4, 2006

Cord said:
Don't forget that it can be hard to steer with the diff locked. 4wd definetly helps to pull the tractor around. You can also use the wheel brakes to help steer the tractor.

Cord, I don't understand this. If the differential is locked, how can the wheel brakes help steer it? When you put on either brake, won't it lock both wheels since the differential is locked? I have a 2 wd, does a 4wd somehow work differently?

normde2001 · Dec 4, 2006

tallyho8 said:
Cord, I don't understand this. If the differential is locked, how can the wheel brakes help steer it? When you put on either brake, won't it lock both wheels since the differential is locked? I have a 2 wd, does a 4wd somehow work differently?

You should only use the differential lock when travelling straight ahead or you can damage it.

Cord · Dec 5, 2006

tallyho8 said:
Cord, I don't understand this. If the differential is locked, how can the wheel brakes help steer it? When you put on either brake, won't it lock both wheels since the differential is locked? I have a 2 wd, does a 4wd somehow work differently?

There seems to be some play in the diff. I know that if I have the tractor pushing straight and I need it to go left, sometimes I can stab the wheel brake and torque the tractor around. This might be the 4wd helping pull the front end. 4wd definetly helps the tractor steer in the slop. It also might be some play in the gears that allows the one wheel to drag for a moment while the other one takes up the slack. Maybe the couple of times I did this things were greasy enough that the tires just skidded. I'm not sure. Mind you, I was not turning tight. I just needed to make a course correction.

I can tell you of an experience I once had on a full size tractor. I was trying to dump some rocks on a rock pile. I got the tractor high centered on a rock and locked the differential in an attempt to get out. It worked. I dumped the load and headed down a trail to the road. When I got to the road, I stopped, looked both ways, shifted to road range and let the clutch out. Well, I had the wheels turned left and I remember the tractor turning 1/3 the way before the front tires started to lay skidmarks. The differential was still locked. Before I could get the tractor stopped I had gone across the road was now in the ditch, stuck, with the trailer blocking the road. While the driveline does twist up, the tires will slip, the tractor will turn, but understeer horribly. Just make sure the diff lock is unlocked when you are done using it or you too could be in for a suprise.