PRC Polaris Ranger Club banner

Downhill on a road with a 99 6x6: D1, D2 or coast

1986 Views 9 Replies 7 Participants Last post by  chris400ho
Seeking the wisdom of this group.

Have a short hill on my gravel driveway of about 100 yds. If in D2, sounds like the belts are whining. If in D1, sounds even more like the belts are whining. If coasting, the whining sound is absent. In any case (D2, D1 or coasting), brakes are required to limit the speed going downhill due to bumps (waterbars) on the driveway.

QUESTION: What is the healthiest way to travel down a hill that requires brakes, D2, D1 or coasting?

Thanks for your consideration,
crossing_patoka
1 - 10 of 10 Posts
Depend how fast you want to go :)

...I'd use low gear...always...
Wanting to go pretty slow, tjm, about 5 mph, due to the waterbar about half way down the hill. There are also lesser bumps further down the hill due to some erosion, even though there is a waterbar.

The manual merely says: "Whenever descending a hill always: 1. Drive directly downhill. 2. Slow down. 3. Apply the brakes lightly to aid in slowing."

But, the manual also includes this on pg 22, under the heading "Braking": "When the throttle pedal is released completely and the engine speed drops near an idle, the vehicle has no engine braking. 1. Release the throttle pedal completely. 2. Press on the brake pedal evenly and firmly."

So, my question becomes conditional: If there is no engine braking, why not coast down the hill? or, in other words, what is the possible advantage of leaving the vehicle in gear when going down a hill? If it is left in gear, it makes a rather high frequency whining sound that is worrysome, and there is no engine braking. Therefore, there is no advantage for minimizing braking friction at the disc brakes due to the retarding forces of engine braking ... there is no engine braking. I assume this means the brakes must do ALL the work to slow the vehicle, whether the engine is in D2, D1 or coasting. I wonder if there is any advantage at all in being in either gear when going down a long hill. The other obvious question in this scenario is: What damage or wear could occur if the vehicle coasts down hills?

I suppose the answer involves some in-depth knowledge about how the belt drive tranny functions and/or how it interacts with the engine when going down hill. I have not yet screwed my head inside that one.

All the best,
crossing_patoka
See less See more
Always drive in low...to maintain engine braking you need to press the gas a little and keep your rpm's up around 1500 or so, that will keep the belt engaged...use your left foot on the brake while keeping your rpm's up a little with your right foot..

you carry very heavy loads and descend very steep hills on uneven terrain while maintaining very slow speeds by keeping the belt engaged using both feet on the pedals...

There will be no damage to anything to coast down the hill while in gear, one advantage to coasting in gear is if you tap the throttle a little the belt will engage and slow you down....
  • Like
Reactions: 1
Like TJM says, slow downhill's requires the Polaris "Two Step," a foot on each pedal - kinda counter intuitive, but you get use to it. The squealing you hear is normal and although it sounds like the clutch is struggling, it's not doing any damage. You can get real engine braking by installing a clutch kit - keep an eye out for more of TJM's posts - he is doing a comparison of the two most popular after market clutches! We're all on pins and needles waiting for his eval!
"I suppose the answer involves some in-depth knowledge about how the belt drive tranny functions and/or how it interacts with the engine when going down hill"

Above is what you need to know. The drive system is nothing more then 2 variable speed pulleys; the drive clutch will engage depending on the weights somewhere around 1100rpm and as you build rpm's changes from small to large diameter, the driven clutch reacts, from input of the drive clutch and rolling resistance just the opposite, this is how you build speed and is known as the Constant Variable transmission or CVT. The transmission, which is where your hearing the whine, is nothing more then a transfer case allowing you to when stopped or at idle only manually engage different ratio's or direction. The only way to utilize engine braking, with a stock setup, is to maintain rpm's above drive clutch engagement, personally I don't like to do this because you burning the belt and working you brakes a lot harder but sometimes you don't have a choice.
See less See more
I've had some fun testing, playing, with the engine braking with the DDP clutch. The method above is the best I've tried so far. Using both peddles you can really creep down some pretty good grades in either high or low gears.
crossing_patoka, sounds like you have the perfect run to practice this maneuver. It kinda goes against everything the brain tells you to do but it won't take long to get a feel for it. Have some fun!
thanks tjm, fswan and pede58, for the indepth and experienced, knowledgeable answers.

running an older machine which i just acquired about a month ago, which i purchased for hilly woods work (maple sap, firewood, etc.), the primary concern is the long term life and service of the vehicle. so glad to know that if needed in an emergency, i can use engine braking to help control speed for safety with the "Two Step" method. i will practice that in a few minutes when i go down the driveway hill this morning, headed to the sugarbush to catalog another bunch of maple trees. but, whenever possible, and based on your cautionary note pede58, will usually take the "gentle approach" when going downhill.

i take it that the "gentle approach", other than completely avoiding going down hills <grin>, is to just creep down the hill using braking at low speed, probably brake-release-brake-release, as needed, then if speed becomes an issue, start feathering the throttle to "rpm's above drive clutch engagement" and continue braking as needed.

i am learning fast about how to operate this wonderful tool, and so grateful for all the good insider info here. i am off to the woods now.

all the best,
crossing_patoka
See less See more
Ditto on low range. It affords the most engine braking.

On a separate note.......if it's whining that bad, that's probably the tranny. If the fluid hasn't been changed regularly, I'd highly recommend a change soon.
low range and just a little gas till the clutch engages should take you down a hill fairly slow unless it is just really steep. if you are in low range and coasting, when you bring the rpm's of the motor up you can feel it engage and hold back. depending on how steep it is some times it will stay engaged if you let off the gas other times you have to stay in the gas. play with it a little and you might find you don't need much brake to go down hills.
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top