Randy Bush
Full Access Member
We have a Topkick graintruck with a Tripple Nickel Cummins in it, Once get it rolling I can shift up and down without the clutch.I usually just use one clutch press while shifting between any of the gears. I do the same while downshifting, getting the rpms close to where they need to be before trying to move into the lower gear. I start out in 1st if I'm dead stopped, 2nd if I'm rolling, and shift around 2k. A little higher than that when I'm pulling a trailer. This truck kind of behaves like the old TopKick I used to drive when I did snow removal. Shifting has to be kind of slow and deliberate.
One thing I noticed was when I set my timing to 9.5 (from ~14) degrees, the drivetrain felt much more forgiving. If I didn't let the clutch back in just right the truck would jerk. If I didn't unload correctly when taking the clutch out it would rattle and clunk. Especially downshifting. It feels like a whole new truck now. I've noticed the EGT gets a bit higher than it used to so I'll have to keep an eye on that but so far I like the change.