What is the phenomenon called...

[Mowbizz]

When you are going up or down hill with a heavy load and the tractor starts rolling backwards (in the case of uphill) or rolls forward in the case of downhill?
Seems like being in 4wd eliminates this.
Brake pedal seems to be ineffective as well when this happens...definitely causes a pucker factor too!

 

[marchanna]

Gravity.

 

[thatguy]

yes.. big issue going down.. brakes are on the rear wheels.. 4x4 will help stop you if this happens

brian

 

[Mowbizz]

So gravity overides the HST?

 

[Mowbizz]

But what exactly is happening mechanically?

 

[mljenkins]

You are free wheeling. Your rear tires are losing traction or in worse case completely leaving the ground. Without 4wd most tractors do not have front braking. Hence your front wheels just roll freely while the rears are essentially sliding. This is caused by the weight shift going downhill (or backwards uphill) with a heavy load on the front but not enough load on the rear to keep the rear wheels firmly on the ground. Hence no amount of braking, downshifting, or hst control will help when this condition occurs if you do not have 4wd engaged.

 

[Peter 315]

When you are going up or down hill with a heavy load and the tractor starts rolling backwards (in the case of uphill) or rolls forward in the case of downhill?
Seems like being in 4wd eliminates this.
Brake pedal seems to be ineffective as well when this happens...definitely causes a pucker factor too!

You might need these if its a big hill

 

[LittleBill21]

your simply losing traction, if you have the balls for it, stepping on the gas and accelerating will sometimes get your traction back, since the wheels have caught back up to the speed your slipping.

 

[Luke'sScreenName]

If I understand correctly...
You need to be in 4wd AND you need rear ballast (big time my friend). That is indeed a potentially dangerous situation.

Ought to be more likely going down hill. Weight pivots on the front tires and the rear tires lift to the point of loosing traction. That means no HST breaking or mechanical breakings. So you just drop the bucket into the ground, prey, and wash your underwear...

 

[k0ua]

So gravity overides the HST?

No, that is not what happens. In fact the Hydrostat acts as a brake, but when you are in 2wd, the only contact patch that braking can be applied to the ground is the rear tires. What happens is that the contact patch breaks traction with the ground and the tractor slides down hill, picking up speed. When you are in 4wd, you can also utilize the contact patch of the front tires with the ground. This helps prevent the sliding tires down the hill.

 

[k0ua]

your simply losing traction, if you have the balls for it, stepping on the gas and accelerating will sometimes get your traction back, since the wheels have caught back up to the speed your slipping.

I have done this exact thing, but it does require stones as you note. It goes against everything your "pucker factor" is telling you to do. You want to stomp the brakes, which does zero good, but if you can accelerate the tires you can sometimes regain traction and hopefully be on more solid surface to start the gentle slowing down process. But a better strategy is usually drop the bucket (lip turned up) to try to slow down, or drop a ground engaging implement.

 

[s219]

Your rear wheels are coming off the ground.

 

[LittleBill21]

I have done this exact thing, but it does require stones as you note. It goes against everything your "pucker factor" is telling you to do. You want to stomp the brakes, which does zero good, but if you can accelerate the tires you can sometimes regain traction and hopefully be on more solid surface to start the gentle slowing down process. But a better strategy is usually drop the bucket (lip turned up) to try to slow down, or drop a ground engaging implement.

its a better strategy if u actually have a bucket or a ground implement, my lawn tractor doesn't...lol

 

[mljenkins]

its a better strategy if u actually have a bucket or a ground implement, my lawn tractor doesn't...lol

Well on a lawn tractor it just becomes a game of how straight can you steer before you reach the bottom. Then you go and buy a set of chains and never take them off after you reach the bottom of a large hill. Although for some reason you manage to do it again with chains on a steeper hill (hey it went up ok right?) and just realize you must either be stupid or need to visit a roller coaster park because it’s safer for your health. Not that I would know that...

 

[Mowbizz]

It is impossible for the rear tires (loaded and with backhoe in place) to come off the ground going uphill...this is a BX25D

 

[4570Man]

Maybe if it's a steep enough hill you break traction trying to go up it and when that happens you slide down.

 

[Bill_M]

Been there, L2900GST & Land Pride FMDR 2572. Was changing up my mowing pattern in what use to be pasture, made about a 35* left turn down hill into a swale. Then proceeded down hill about 40' & hit a 10" tree with the sidewall of the left rear tire. Don't remember how far before I stopped but I did head back to the house & sat down with a drink. Needless to say I didn't mow in that pattern ever again.

 

[Fallon]

Same issue with my L3200... Had a 100-200lbs gate on the pallet forks. It was only 100-200lbs so I didnt bother with ballast. Came down the gental slope behind the barn to lay the gate up against it. Let off the go pedal, kept going. Hit the brakes, kept going. Left skidmarks on & under the tractor, kept going. Now have a couple of palet fork shaped holes in the back of the barn.

I always keep it in 4wd & ballast on the 3pt now. It wasn't fun making that ride with no rear traction & not having the front axle engaged.

 

[Luke'sScreenName]

It is impossible for the rear tires (loaded and with backhoe in place) to come off the ground going uphill...this is a BX25D

It is impossible for the rear tires (loaded and with backhoe in place) to come off the ground going uphill...this is a BX25D

Might want to repeat this considering you're the OP or start a new thread! Certainly changes things...

 

[Mowbizz]

That is why I mentioned it. There is no skidding no lifting of wheels just rolling backwards out of control.