18 speed shifting

Small hills I will split, Larger steeper hills I take whole gears as you loose rpm's fast enough it usually negates the split.

 

Pulling 2 trailers? Downshifting, I would split all the gears until I found the gear that would hold at 1400rpm. The full gears are spread too far apart. What you have to do is downshift a bit higher in the rpm range...like at 1300rpm. That should put you around 1600-1700rpm on the half gear. If you're heavy, going too low in the rpm is what is messing you up. Plus, lugging a heavy load will really heat up those EGTs.

 

I always pull hills around 1550 rpm in the next lower split then will hold , then roll out of the throttle a bit , that keeps my pyro about 1k, and just turn the fan on an kick back , but that's just me I'm rarely in a hurry

 

I do a run a couple few times a month that goes to Boone NC and I climb the hill on us 421 going into Boone , that's a steep mother , that's the way I run that hill every time , I'm always close to 80k , I could go faster but I take it in 11th gear at around 25 mph , it's a ten minute climb

 

What kind of truck? Rear end? Hill grade? Gross weight?

My 550 hp C-15 CAT will pull all but two hills on the I94 in Wisconsin in 18th at 75,000 lbs gross with 3.73 rears.

 

It's really steep , my gps says 12% in parts but I don't think all of it is that bad , I can tell you it's steeper then any interstate hill I've seen.
I think I've been on them all.
565 cummins 18 speed 355 gears 24.5 LP tires

 

I used to run it harder but I melted the slide bushings on my stacks out , saw goo on the steps of my truck and thought I blew something , but then realized the bushings melted and dripped down

 

Pulling 130k doubles up grades with an 18 and I usually split to milk every last bit of power I can but it really doesn't make that much difference. I like to split and other drivers I run with don't. We both climb the hill at the same speed. Whole gears are usually easier to grab though. For the split shift I'm bleeding speed so fast when I'm off the throttle that I don't rev more than 100 RPM to catch the next half gear down. Just a little tap of throttle is all.

Typically when my RPM's are down to 1450-1500 I'm already grabbing that next lower half-gear, on the throttle from 1650 back down to 1450 and shifting again. If I let the RPM's down to 1400 then I'm better off just grabbing a whole gear, otherwise by the time it engages from a half-gear shift the RPM's are only 1500 and I need to shift immediately anyway.

But every truck is a little different. I don't shift on any specific RPM, instead I go by what the motor sounds like. Key is do whatever is comfortable for you and the truck. If you are slamming splits then don't. Just downshift whole gears and it is fine.

 

You guys make me jealous! Running a 500hp Cummins, 129,000 lbs, 6-8% grades have me feeling good if I can stay in 5 over and pull close to 20mph.