Hill descent

Catch95 · Feb 9, 2005

I have a steep hill at the rear of my property. I was coming down the other day after doing some slashing. I have a small Jinma 20hp 4wd tractor, which I've had for a year. I've never had any problems on this hill but the other day it got away from me and I had one terrifying ride.

I was in 4wd, and 2nd gear in low range, with the implement on the 3PL lowered. About half way down it started to runaway. I reacted instinctively and gave it a little bit on the brakes but it just started to slide (there had been some light rain). So I concentrated on keeping it straight and hung on for the ride. Fortunately I always wear a seatbelt and have ROPS. Near the bottom the tractor "caught up" and started to slow.

I'm not sure why this time I got into trouble - but I was still shaking minutes later.

What is the best way to handle this - should I have used the diff lock, and can you engage a diff lock at speed - I guess I figured being in 4wd would be all it would need?

My long time farming neighbours said I should have been in a higher gear, but this doesn't make any sense.

Would appreciate any advice

Mark

getut · Feb 9, 2005

When you say "run away" do you mean you were sliding down the hill with the wheels either not turning at all or at least turning much slower than you were moving? or do you mean the engine compression was not enough to keep the weight slow, so the engine RPM kept climbing as the wheels turned faster?

Bob_Skurka · Feb 9, 2005

I deal with hills have had a couple wild rides myself. You should have been in a LOWER gear not a higher gear. You should stay off slopes until the grass is DRY. So those two things probably contributed to the problem. But I also wonder if part of the problem was the rotary cutter, it might have been working against you and keeping the tractor moving forward (all that depends on the sophistication of the transmission on your Jinma, which I don't know much about) but the flywheel of a rotary cutter spinning at speed, on a simple mechanical transmission, could essentially power a tractor forward when you don't want to go forward. I've seen/experienced this myself with antique gear tractors. Disengaging the PTO might have helped, but I suspect you were hanging on and the thought of attempting to disengage the PTO probably didn't enter your mind, and again, might not have helped depending on the type of transmission you have.

rbarker · Feb 9, 2005

( I was in 4wd, and 2nd gear in low range, with the implement on the 3PL lowered. About half way down it started to runaway. I reacted instinctively and gave it a little bit on the brakes but it just started to slide (there had been some light rain). So I concentrated on keeping it straight and hung on for the ride. )

Yikes! /forums/images/graemlins/shocked.gif I think you did about the only thing you could do in that situation by keeping it straight and riding it out. /forums/images/graemlins/crazy.gif Was this a real heavy impliment that "pushed" the tractor down the hill?

Glad your safe! /forums/images/graemlins/grin.gif

BTW, on my Kubota the diff lock is only supposed to be engaged from a stop. Don't know how it is on your Jinma, though.

tough451 · Feb 9, 2005

I always choose second or 3rd gear in low range on my hills I never hit the brakes unless I have too. You did well by holding a straight line.
Some times if you have alot of weight behind you and your gearing is to low it will have a similar effect as hitting the brakes is this what happened.

Henro · Feb 9, 2005

Been there, experienced that...

Chains seem to help. I kept mine on the back all year long last year due to all the rain we had.

Like Bob S said, keeping off the slopes when it is wet helps the most probably. IN my case that was not possible. Chains are no guarantee either, but using chains seems to be better than not having the chains on...

Todd_C · Feb 9, 2005

Glad your o.k. I had a similar problem last year before I got my tractor. I had a small trailer behind my ATV and loaded it with about 700-800 pounds of wood. I stared down the hill behind my house and the ATV started sliding. I was able to make it to the bottom of the hill by the skin of my teeth. I had the ATV in low range and the wheels started sliding. I opened up the throttle and held on. I decided to keep the tires turning rather than trying to control a skid. It worked but I should have known better than attempt to control 1,000 pounds with a 500lb machine. I was lucky. I have been lucky on my tractor so far. No real close calls.

johan3400 · Feb 9, 2005

I think you did a fine job just keeping it straight. I had the experience of riding a JD950 down a steep hill with a large load behind it. I believe each time we have close calls like this one we learn. Do you have Ag tires on the back or Turf? Do you have the back tires loaded or some type of weights? The wet grass adds to the risk. What would you change to be safe the next time? Maybe the next time you could lower the 3pt all the way down and that would help.

Catch95 · Feb 10, 2005

Thanks for all the posts on this.

Basically I was coming down the hill faster than the wheels were turning. I did have the PTO engaged, thinking I would mow the track on the way down - my little tractor struggles to do it on the way up.

Should I have accelerated to get the wheels to catch up - seems like the opposite of what you feel like doing?

I might put a post on the Chinese Tractor board re when you can engage the diff lock on a Jinma.

I do consider myself lucky - better than the son of a neighbour of mine who lost it on a much steeper hill, jumped (survived even with no belt or ROPS) before the tractor went off an embankment and became airborne - landing up high in a huge tree. I would have loved to have been there when he had to front his father.... Apparently they cut the tree down, the tractor came down with it, and he drove it away - something about old Fiat tractors.

Mark

Jim_Fisher · Feb 10, 2005

Catch95,

( Should I have accelerated to get the wheels to catch up - seems like the opposite of what you feel like doing? )

Good question.

You could have used a higher gear and a low engine speed as your neighbor suggested. That may well have been sufficient to prevent the incident. If you still started to slide, you could have accelerated to try to synchronize the wheel speed with the actual rate of travel.

You could have disengaged the clutch and pumped the brakes very gently to slow your descent. Since you had the tractor in four wheel drive, the front wheels would have helped to slow the tractor. Remember that if the front wheels are not turning they will have very little effect on the direction of travel.

You could also lift the three point implement enough to transfer some weight to the tractor wheels. The down side is that you would take some weight off of the steering axle. If the tractor is correctly ballasted, there shouldn't be a problem.

I think that you realize that applying the brakes when the wheels were sliding did nothing to positively affect the outcome of the situation. It's not easy to place mind over matter in an emergency situation but sometimes that is what has to be done.