shifting with jake

hey all, just wondering if you had some advice on upshifting with the jake on. i really need to shift at higher rpms on hills with the dump truck, but without the jake, my speed and rpms fall too much and the engine gets lugged. the truck has this stupid turbobrake (same thing as jake, but so quiet you really cant hear it at all), so i cant time my shifts based on the sound of the jake.

i guess i could wind the engine way up and shift like a cowboy, i duno tho, there must be a really smooth and skillful way to do this, such as maintaining the slighest foot pressure on the throttle to keep the brake off, and then during the shift just letting the foot off for a fraction of a second to help the rpms drop just enough so that the shift can be made quickly enough. thanks for everything - dan

 

My instructor told me not to shift with the Jakes on

 

I am assuming you meant to say that with the jake on your speed and rpm's fall too much. The easiest way is to just switch it off (or, if you use the clutch when you shift the jake wont (or shouldnt) work anyway)

 

If you shift with the JAKE or any other engine brake you take the chance of unnecessary damage to axles, drive line, transmission, motor, tires, and even the frane crossmembers. The long and short of it is, DON"T!! Company truck, Your truck, even your buddies truck. YOU ARE RESPONISIBLE FOR YOUR ACTIONS AND THE DAMAGE YOUR ACTIONS CAUSE!! BE SAFE AND TAKE YOUR TIME.

 

Just float your foot on the clutch petal. The slightest pressure will trigger the switch, so the brake will not come on, this also will have you ready in case you miss a gear to clutch it back in.
Turning it off is still the safest bet however.
Driving local for many years I noticed that the trucks I would drive were set up for pulling differently than road trucks. The vast majority of them I needed to run up to a higher RPM to get any acceleration or pulling power on a hill.

These were mostly older macks, ford 9000's, freightliners and KW's.
Throw in a Diamond Rio to round it out lol.
These trucks were all set up for local operation. They would bog out and almost stall if you tried to progressive shift them or shift at low RPM like in a road truck.
Some had Jakes, some did not.

 

I can't think of any reason to NOT turn the engine brake of when you are upshifting. It can save a lot of mechanical problems.

 

you mean to tell me there is a switch to shut the jake off?????


K

 

Yeah no doubt mine stays on all the time unless I'm bobtailing. All you have to do is rest your foot on the clutch enough to disengage it while shifting. You're still floating basically.

 

When I worked construction, we had a letter from Jacobs International of Bloomfield Connecticut posted on the office wall. It stated that they (Jacobs) warned against useing the engine brake to upshift, and we had several Macks with six speed transmissions behind Maxidyne engines.
I use slight preasure on the foot feed to prevent the engine brake from coming on while shifting. The only time I turn the switch off is if I'm in a town where it's not allowed to use the engine brake. With some practice, shifting without letting off the foot feed completely becomes natural.