Comments By Cleft_Asunder

Things are getting a little hostile here. Let's all down shift a gear or two. First off let me explain my thought process for the Jake. You have to look at the fact that you're controlling two separate vehicles. When you use the Jake you're only slowing one vehicle at a time. The problem with this is that during wet weather you're only slowing the front vehicle and allowing the trailer to want to take the lead. Anyone can see why this is not an ideal situation to be in. Can you use the Jake on wet roads? Of course, but why would you want to add more risk then need be.

As far as shifting, I think you haven't given floating gears enough of a chance. Using the Jake may be the problem or it may be the old tranny. In my opinion you need turn the Jake off and learn to use proper braking techniques. Then maybe you can really start controlling your rpm and road speed well enough to make smooth shifts.

That's all I got. Have a good day

Well, I'm going to try no jake brake when I get back in the truck. Maybe it will help with floating.

The thing with jackknifing is, once you lose control you're pretty much done. It happens in the blink of an eye.

I understand the deal with trying to maintain your speed, but that's what the brake pedal is for. Relying that heavily on the engine brake will make you a lost, blind puppy during times when you absolutely cannot use it because the road is covered in ice. You won't know what to do or how to drive properly because you've relied so much on those engine brakes. It only takes one time, one little slip, one error and you're done. Those chances sky rocket with those engine brakes engaged - especially if you're using them on curves.

Those are bad drivers you're thinking of. A good driver who feels his trailer and has good instincts knows when he's coming close to tipping, skidding, or jack-knifing. He knows when to use his EB. I see veteran drivers taking turns way too fast in poor conditions. They'll do turns at 65mph that I would do at 55mph because I can feel the trailer start to tip. I've been on semi-icy roads where owner operators were going past me at 65-70mph. And you'll find these same drivers pulled over to the side of the road if the sign says "icy conditions, use caution." If a sign doesn't tell them, or if it's not blatantly icy, they think they are safe. I can tell it's turning into ice by the reflection of the on-coming vehicle lights on it. I can feel my drives slipping slightly. Yet these guys are still going past me like its a summer night even though its below 30 degrees.

So the point I'm making is it's about skill, intelligence and common sense, combined with confidence,rather than rules. Bad drivers are highly reliant on rules rather than feeling and knowing their tractor and trailer. Those drivers are dangerous. A good driver will not jackknife if forced to go down a snowy hill with 'high' engine braking because he feels the truck and trailer. It's a bad idea of course, and serves no purpose, but can that person do it? We're not supposed to drive on black ice either, but can you do it confidently and safely?

From the jacob's brake manual:

The Jacobs Engine Brake depends on the free flow of engine oil for operation, so be sure to let the engine reach full operating temperature before switching on the engine brake. Normally, the engine brake is then left in the “On” position whenever you are driving. The exception is when roads are slippery due to bad weather conditions. Refer to the section entitled “Slippery Pavement” for specific operating instructions. The operation of the Jacobs Engine Brake is fully automatic, once it is turned on. When your foot is off the clutch and you remove your foot completely from the throttle, the engine brake is automatically activated. (There are some systems that will activate only once the brake pedal is depressed.)

Here is more info: http://cumminsengines.com/powerspec-isl-engine-brake-features-and-parameters

And it confirms what I said on cummins website. The engine is designed to allow the mechanic to set the engine brake activation in relation to cruize control speed. So for example, you can set the EB to engage at 1mph after your CC set speed of 60. This proves

From cummins website:

Engine Brake Cruise Control Activation The Engine Brake Cruise Control Activation feature permits the Cruise Control feature to automatically engage the Engine Compression Brake should the selected vehicle speed be exceeded while the Cruise Control feature is controlling the engine. This reduces driver workload and thereby encourages use of the Cruise Control feature.

I can't understand why that would be. Does your leg get bored? Maybe audio books might give your leg something more enjoyable to do than clutching for no reason, eh? Does your leg like Westerns? I recommend "Zane Grey: The Last Trail" - great story. It'll have your leg hoppin like a one-legged driver in an 18 speed!

No it's because I like to. It provides a larger window to shift into since the pressure plate (being lifted slightly) and clutch disc springs work together to create a buffer between the flywheel and transmission components, lessening the strain on the transmission components mainly under heavy loads. Clutch wear is very minimal if you DC well, and because you're only pressing the pedal in 1-2 inches, the pressure plate diaphragm springs will hold up a long time. I think a company has serious priority issues if they are fascists about double clutching. A new driver who is good at DC but bad at floating will make that transmission so slacky over time. My instructors new cascadia was already clunky and slacky at 30,000 miles.

Man, Cleft, usually when we hear something really stupid like your engine brakes always staying on we try to educate the new driver about what they're doing wrong. And that's clearly not working because you know much more than experienced drivers. So typically we just sit back and tell ourselves "He'll learn over time." But in this case the only way you'll learn is when you'll jackknife and then it will be too late.

Just remember that some of us are trainers too.

And the reason your trainers truck was clunky and slacky is because he has rookie drivers learning on it and every rookie drivers knows just how much they grind the gears.

And also, by using the clutch to shift gears you're actually using more parts. Floating gears properly, that means not being a dummy and having the engine brakes on all the time, is the best thing you can do for your truck when it comes to keeping it in good conditions.

Total veteran ego right there. I never implied I know it all. Explain to me why cruize control is set to turn on the engine brake at 4 mph after your set speed. Why would this feature exist if you aren't allowed to run the engine brake while cruising???

Also, the veterans are always disagreeing and contradicting each other but you make it sound like things are set in stone.

Cleft Asunder, the reason it won't slip out of gear is because your RPM is not right - the jakes make your RPM fall off way too fast for you to float the gears easily. An experienced driver may be able to do it, but even they will have problems in those lower gears. I wish I could sit in the truck with you for a few minutes and show you a few shifting techniques - it would make your driving experience so much more enjoyable.

The issue isn't rpms falling too fast, I have no problem keeping up with rpms. The fork literally will not disengage even when I let off the gas so there's no strain. I literally gets stuck. This could be due to the mainshaft/countershaft issues. My transmission is not 100% perfect, it was abused by a previous driver. (it still feels really nice when double clutching though) So I can only float it cleanly

I wonder about that jake brake. Is it on, lowering the rpms, when I'm not touching that gas pedal?

I can't understand why that would be. Does your leg get bored? Maybe audio books might give your leg something more enjoyable to do than clutching for no reason, eh? Does your leg like Westerns? I recommend "Zane Grey: The Last Trail" - great story. It'll have your leg hoppin like a one-legged driver in an 18 speed!

No it's because I like to. It provides a larger window to shift into since the pressure plate (being lifted slightly) and clutch disc springs work together to create a buffer between the flywheel and transmission components, lessening the strain on the transmission components mainly under heavy loads. Clutch wear is very minimal if you DC well, and because you're only pressing the pedal in 1-2 inches, the pressure plate diaphragm springs will hold up a long time. I think a company has serious priority issues if they are fascists about double clutching. A new driver who is good at DC but bad at floating will make that transmission so slacky over time. My instructors new cascadia was already clunky and slacky at 30,000 miles.

Brett, if he's driving with his Jake on all the time that may explain why he doesn't like floating gears.

I don't like floating gears because it wont pull out of gear very often even when I let the gas pedal off to relieve the pressure. It gets completely stuck in the lower gears sometimes. Even pressing the clutch pedal in slightly doesn't help take it out, so I have to press it down 2 inches instead. And then I'm double clutching again, so what's the point of floating if I can never make it a habbit? And the engine brake has nothing to do with it. It comes on after you shift.

The bad news is that when the testing is done, it will have this separate device that you have to wave in front of PRE/POST trip spots. For example, if I'm near the engine, I have to be there 3 minutes (no less), or near the 5th wheel et cetera. Everything will total about 15 minutes combined. I don't think that feature is in right now since I bet the drivers would be talking smack about it.

Now this is the first I've heard of anything like this. Are you saying you might have to carry a device around that will measure how long you're standing near certain parts of the truck while doing a pre-trip?

Exactly. This will turn off drivers from signing up if they find out about it, and the ones that are signed up will be reluctant to stay. I recall it being called zonearc or something but I can't find info on it. I will ask around and update this post in the future.