mackinit

ekennedy..how do you mean you double clutch when splitting? how is that procedure done exactly?

forgot to mention that i did get some stick time today and this was the sequence inwas using while down splitting. foot on throttle and hit button down to split at1500 rpms, let off throttle and let split engage and quickly get back on throttle. it seemed to work but is this bad practice? ive tried splitting down while off of throttle, hitting the button down, then hitting the throttle again as fast as i can and it kinda sounds like its grinding and makes a sound that to me doesn’t seem right. doesnt sound very smooth.

1600 was just an example and thanks for clarifying thats to high to down split. but in that case, 1600 rpms, foot off throttle, hit the button down, then hit the throttle right after split? is that right? if so, what should the split shift sound like? under normal driving conditions while loaded, on/off highway for example, what rpms should split shifts be made in general..up and down? glad i found this site. a lot off good info on here. i did read about mackr1989’s problems and my issue seems to be the way im shifting, not a problem with the transmission. but i did notice that when i ran the split test while the truck is at full air pressure and not running, the splitter doesnt always actuate quickly splitting down. sometimes it’s immediate, sometimes its delayed, sometimes it doesnt seem to move at all. i hear an air sound and knock which i assume is normal when it does work immediately or delayed. what does the delay or no apparent response mean?

luckily i was able to find the owners manual and it explained a lot. what it doesn’t say is at what rpms to split at. say at 1600 rpms, i want to down split, do i hit the button down while on the throttle? or off then hit it? i tried a bunch of different ways and it didnt work either way for me. is 1600 to high or should i be down splitting around 1400?

my company has a 2000 rd triaxle with a mack 18 speed in it and i think it has a 400 or 427. it is soon to be my truck. problem is, the previous driver left the company and i dont have anyone to teach me how to shift it. i had never shifted a splitter transmission until today and i did awful. the gears ground so bad when i was trying to split. at what rpms do you upsplit and down split.? what is the max rpm and minumum rpm you can split? going down hill at moderate speed, do you heel/toe to split down while throttling up or throttle off then split then throttle on? preselect splits. are there normal sounds i should be aware of that may have me wondering if i did something wrong? there are so many more questions i have and techniques i need to learn before i really get on the road. i need a lot of practice and im scared of damaging this transmission.