How to get a loaded trailer down a steep bank with Dyna VT

[Andrew]

Secondly some of you say that you have to choose the correct ratio but how do you do that on a JD?

Pull the stick back.

 

[Galcam]

Yes Andrew, of course you can pull the stick back or take your foot if the accelerator to slow down but choosing a ratio?

 

[davidroberts30]

Yes but could there not be other factors at play as well , such as the different transmission drags .

Back in the day and may well still do but I haven't been to one in years . If a car was getting dyno tested it would do the run and then the clutch pressed to measure drag as it coasted down , to work out engine output .

Could the same be happening here and making it "feel" the vario has less engine braking , added to his valid explanation?

I am convinced rightly or wrongly there are factors at play here . Take my baling example as have never used the t3 dyna 6 6480 on sprayer. Vario set to sv1 7kph lugs down to say 5 going up hill. Sv2 could be set to 3kph expected to run off slightly and hold itself back to well bellow 5kph but cannot in my experience and take off over revving high enough to throw a fault code if left un braked . D6 can in similar circumstances .

Edit here as see the duck has answered on exhaust brake being at least a benefit [emoji106].

My comment is an exhaust brake would be a benefit but also agree it would be a benefit on any gearbox .

But everyone says a vario is inefficient so you would think it offer more engine braking ?

 

[Andrew]

Yes Andrew, of course you can pull the stick back or take your foot if the accelerator to slow down but choosing a ratio?

If you pull back the stick, the computer will select the correct ratio to meet that speed.

 

[Pheasant Surprise]

But everyone says a vario is inefficient so you would think it offer more engine braking ?

Presume you’re referring to the power conversion efficiency (hence losses through the hydrostat and hydromotor(s)? If so then in terms of increased braking efficiency- it would amount to the sum total of diddly squat

Any engine braking (including additional retardation from an exhaust brake) follows the mechanical “path” through the box via the input planetary, sun gear and then out via intermediate low/high range and then out to the axle.

That’s the gist of what the duck has been banging on about.

 

[Kiwi Pete]

The duck explained it further back in the thread
It's to do with Internal egr on the exhaust stroke of the engine that it doesn't offer the same level of hold back

Our new Merc 1835 truck is the same, put 8 ton of lime on the back and there is little stopping it, even the exhaust brake struggles to contain it.
I've only left the ABS on once, and once was enough!!
Agree with switching to stick mode on steeper stuff, instinct causes us to lift off the pedal when we feel that "push", and it isn't nice when the front tyre breaks traction and spins backwards

Been there, done that.

 

[holywell farmer]

The duck is not always right ,gets red mist from time to time from his days in the brain washing camp

Do your fendts have good engine breaking?

 

[Chae1]

Do your fendts have good engine breaking?

Think fendts have a history of engine breaking!

 

[Speedstar]

Think fendts have a history of engine breaking!

Think you have spell exhaust brake incorrect

 

[Pennine Ploughing]

will this have engine braking on it ?

 

[sawdust]

will this have engine braking on it ?

Big Reds. And some people said multi power was a bad thing...

 

[holywell farmer]

Thought some problems users get with vario is when transmission is used to slow speed rather than tractor breaks ?

 

[jh.]

Thought some problems users get with vario is when transmission is used to slow speed rather than tractor breaks ?

I've never understood that one tbh , other than over revving the engine like when dropping gears to quickly with anything .

 

[Andrew]

Thought some problems users get with vario is when transmission is used to slow speed rather than tractor breaks ?

Normally it’s inadequate trailer brakes causing the tractor brakes to overheat and contaminate the oil, or other form of oil contamination, then the tractor BREAKS.

If the gearbox is strong enough to accelerate a certain mass then it should be strong enough to decelerate the same mass, otherwise it’s not fit for purpose. (Operator abuse aside).

 

[holywell farmer]

I've never understood that one tbh , other than over revving the engine like when dropping gears to quickly with anything .

It's like in my car use the breaks before change down a gear

 

[holywell farmer]

It's like in my car use the breaks before change down a gear

It gives transmission a bit of shock if change down gears at high speed

 

[jh.]

It gives transmission a bit of shock if change down gears at high speed

Exactly , no reason for any shocking with a cvt as no need for clutch , so only engine revs to watch using a cvt to slow down surely

 

[Andrew]

It gives transmission a bit of shock if change down gears at high speed

If done correctly it doesn’t cause any damage. If the engine is in 5th gear at 4000rpm you wouldn’t change down to 1st would you. But if it was at 1500 you would change down to 4th quite happily - hence my comment about operator abuse.

Same thing with varios - pull them back slow and steady watching the engine rpm you’ll be fine.

Would think in any case the engine was more likely to go bang than the gearbox.

 

[holywell farmer]

Exactly , no reason for any shocking with a cvt as no need for clutch , so only engine revs to watch using a cvt to slow down surely

Any tractor with gears it's case on the breaks first easy of foot pedal then down the gears,

 

[Andrew]

Any tractor with gears it's case on the breaks first easy of foot pedal then down the gears,

Why? Go talk to a few HGV drivers.