Shifting in a tanker and dealing with the surge!

I had difficulty managing surge (our unwelcome French friend) when I transitioned from manual to auto in the freightliner cascadia. From a stop anything more than 1/4 throttle and the transmission would shift at 2100rpm for gears 2-5 which would make the qualcomm yell at me for heavy throttling, and would insure the shift happened right as the surge hit (for most loads). I ended up running in “manual” mode, and forcing the shift at lower rpms or if needed, holding a higher rpm until I felt the surge, and then shifting with the paddle. This seemed to solve the problem, but my trainers prefer me using the full auto mode to “reduce workload”. Is anyone else experiencing this problem in the 10 speed auto Cascadia, if so what are you doing to manage surge?

 

When accelerating: back off the throttle to remove power from the drives, wait 'til the surge hits the front, then slide it into the next gear and gently roll into the throttle. If you give it too much throttle right after you shift, the surge will hit the back of the tank much harder than necessary.

 

I've got the same set-up. Slow and steady seems to work best for me. Don't get behind me if I'm at a traffic signal.

 

Just be sure to give those brakes a stab before pulling up on the scale at the chicken house.

 

Also like to add if you’re on a scale trying to get an actual true weight.... when you get into position and come to a stop, hold brakes in for about 5 seconds or so and then release pedal and let truck & trailer rock back & forth instead of setting the brakes. It will roll forward a few inches & then backwards a few inches and will come to a complete stand-still a whole lot faster than it would if you set brakes and let liquid keep sloshing around the stationary tank. Kinda hard to explain lol

Another tip... If you have an air-ride tanker, when you park to unload, set the trailer brakes but leave tractor brake knob pushed in. This will allow the trailer to “walk out” and lower the rear end another 4-8” depending on make & model. After it finishes walking out then you can set the truck brakes. This will prevent excess heel by giving the tank a steeper downward angle.

 

Well, I believe you did explain it. Thank you. I went round and around with an ODOT scale officer before learning this.
But, I kept my cool and only received a warning.

 

It was E Z teaching people to shift a R-600 with the 5 speed....taught the guys to complete the shift and get the clutch up and wait a bit before hitting the throttle. Getting the clutch up make the drive line smoothly roll the load back and it would gently hit the back as you eased on the throttle.

One of my oldest drivers does not like an automatic as you have to stay on the throttle to keep the drive line turning [bothers him when backing as he can't just let the engine idle like he could with a clutch] so this would not be the cure for an auto...

The overall problem is the rate of surge is dependent on the viscosity of the product and how much is in the tank.

An 8000 gal tank with 7600 gal of Acetone doesn't surge as much as it jiggles around BUT if you fight the jiggle it will roll you over; you got to just let it rock and roll around back there.

2250 gal of slurry [22.5 lb/gal] in an old 5000 gal latex "tight fill" tank, in traffic, will hit the back after each move with traffic so much that with a little upgrade you think another loaded truck just rear-ended you.

 

Try hauling slurry in a 7K gallon tank.
And yes, up until last year we had a few Mack’s with 5 and 6 speed transmissions. Very easy to drive and control the surge.

 

It’s not so much the shifting as it is the acceleration, and braking. When you wind out a gear, you let off the pedal. When you feel the bump at the front of the trailer, shift your gear. Now the important part, DONT MASH THE PEDAL TO THE FLOOR! Wait till you feel the bump at the rear of the trailer to give it any serious throttle. Whenever possible, when braking, light apply brakes until load hits front of trailer, and then increase braking pressure.

 

If you’re in an auto don’t forget to switch from E (economy) to P (performance) after you load. That way it’ll run through the gears and not try to go from 3rd to 7th