Freightliner auto transmission on steep down grade

Is there not a Descent Mode wherein as you get to the crest in the hill just before the drop, set the Jakes on stage 2 then push your cruise control button for set speed? This was explained to me from another driver who says he does this before going down steep grades.

 

Not that I know of, but will definitely try that next time I'm on a hill

 

Part of the problem of using the cruise control on downhill drivers with autoshift, is drives not knowing how to go downhill without using it like in the winter. Plus not learning what the autoshift can do. So you know when your beginning to go beyond the limits of the system.

I was taught how to go downhill in the snow without any engine brakes. I just used the engine brake to let me go down the hill faster. I think some people use the engine brake to get them down a hill. That's why with this autoshift you have watch out because I see at it's set up like summer mode.

Their are a couple different ways of driveing downhill like I always told you want low RPMs not because is bad for the engine. You want low RPMs for in the winter because that's how you save yourself from a possible jacknife is pulling the trailer downhill. If this autoshift is setup to 1800-2300. We can't pull the trailer downhill. I should say you can you just step on the pedal and it will pull the trailer. Your also not supposed to use cruise control or engine brake in snow or ice roads. So you avoid that probably.

Not every one teaches this way of driveing unless your out west, it seems. So driver get in the bad habits of just setting the Cruise control instead of learning how drive I guess. I think the cruise control is a good way to see what the autoshift can do in the summer. Then as drivers we can drive the truck the same way. Then if you notice you going beyond the system limits on the big hills or in the snow or ice you can save yourself from accident

 

In the winter conditions I would highly recommend using Manual mode to prevent the thing from auto jaking with high rpms possibly momentarily locking up the drives and causing an uncontrolled skid into a jackknife.

Plus I did a video last winter I was going eastbound on an icy road in manual mode I look over to the westbound side a company colleague in an autoshift truck was stuck on a little bitty uphill bunny hill and blocking 3 mile of traffic behind him. I can't confirm it but I bet he was in Auto mode instead of Manual mode and climbing the hill the shift sensors went berzerk and couldn't figure out which gear to be in and once he stopped on the uphill icy road, could not get going again.

 

Our dd12 autos at Prime do this. You pop the engine brake on and set cruise speed and it will keep you at that speed.
Normally with the cruise set on 62 mph it will start engine braking on it's own around 68 mph, or if running at 58 it will hold speed around 65 mph. If for some reason I want to go down the hill slower than that I do the method you are talking about. Sometimes it gets a little funky and I will manually switch between the engine brake settings.

Another quirk is say you are cruising in Cali at 58mph and you start to pull a hill, it will sometimes speed up to 61 or 62 mph to get up that hill. Could be a problem in Kern county.

The engine brakes on these freightliners are much more powerful than the old 10 speeds we had. I've never heard anyone complain about them in fair weather. Now a 7 miles 6-7 % downgrade in snow and ice? Terrifying being locked out of manual mode and the truck starts coasting when you let off the service brake.

Edit: We asked our freightliners rep how we are supposed to navigate in these situations, and he explained that we are to hold down the brake pedal just enough to keep the truck from going into e-coast. It requires enough pressure to show on the applied pressure gauge so I'm not wild about this. Try it in good conditions for yourself so you can fallback on the engine brake if you get the brakes hot.

 

Yes, but the lever has to be in the off position to let the computer take control.
The cruise control won't even engage if the engine brake is set to anything other than off. At least that is how mine works.

 

It's pretty obvious that we all have different experiences with the auto's because of how they are programmed so differently by different companies.

 

I just hate the stupid E mode that ours goes into. Of course, I slip seat and the other drivers have ran our trucks into the ground. Leasing from Ryder doesn't help either. We have 2-3 trucks out every week with transmission issues. Our creep mode doesn't even work anymore... makes backing fun. I envy you folks with smooth operating DT12's!

 

The E coast is a normal part of the auto set up. That's not a parameter setting. It's designed to conserve fuel

 

True. Seems like you end up using more brake though.