Skip shifting an 18 speed

Discussion in 'Heavy Haul Trucking Forum' started by tomkatrose, Feb 7, 2014.

  1. crazycanuck

    crazycanuck Bobtail Member

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    Everything above is good info BUT never get lazy and use bull low in high range instead of dropping to low range forth gear. Like a 13 it is considered a dry gear. You may get to where you can pick up or drop three at a time when necesary. The 18 allows many more options for keeping the optimum rpm.
     
  2. GOV'T_Trucker

    GOV'T_Trucker Heavy Load Member

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    I never really use lo or lo-lo.. I start right from 1st... I basically shift it like a 13 speed most of the time.. The only time I split the lower gears is when loaded heavy and going up hill... It's just habit to split the higher gears even if I am empty.. If I bobtail then I just shift all the way to 8th and then split into the higher end... The only lower gear I split is into 4high when going up hill...

    The only shift I find to be tricky is when I am loaded going up hill... Is shifting from 5th low to 4th high.. For some reason it's a tricky one...

    I do have a question and I have never tried it myself as I am worried it wouldn't be good for the tranny... One of the drivers at my work told me years ago that you can shift from 4high to LO and then into 5th.. Does this make sense?? Like I said I don't wanna try it because I don't need to but most importantly I don't want to destroy the transmission.
     
    Macneil Thanks this.
  3. Cetane+

    Cetane+ Road Train Member

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    Its a wasted step. Just flick the splitter as you shift from 4 high to 5 low. ``
     
  4. crazycanuck

    crazycanuck Bobtail Member

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    sounds like he was talking about pre and post shifting. This was a big concern in the day of the Mack 14 speed. You had to pre-select shifting up and post-select shifting down. If you did this wrong the tranny would get between gears and could not be shifted until you came to a clunk, clunk, clunk stop. This caused many runaways on steep grades.
    Since I said Mack I should offer a little advice on the Mack 18. When picking up a split shift, say 3rd over to 4th direct, dont pre select. Instead shift out of 3rd, cross the gate, and then split to direct just as you slip into 4th gear. This will eliminate that annoying grinding sound as you try to set your rpm just perfectly as is required. It will also stop you from pounding on the top of your shifter handle. Bin there.
     
  5. freightrunner

    freightrunner Heavy Load Member

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    Lol. I thought it was normal to not use to splitter??? When I did drive a 18 spd I used it in 4L and in 8H.
     
  6. Macneil

    Macneil Heavy Load Member

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    I shift my 18 the same way and am always loaded at 63.5KG(140k lbs)..Only time I ever split the bottom gears is if its a good pull up a slippery hill and I need to get my momentum up..
     
  7. Macneil

    Macneil Heavy Load Member

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    A guy I used to work with did this once in a blue moon.. Ive never tried it but have been in the truck with him when he's done it and it did work..I don't know how bad it is for the tranny mind you lol.
     
  8. crazycanuck

    crazycanuck Bobtail Member

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    won't hurt a thing. The 18 speed can be split at any time in any gear...or not. This tranny gives you full reign to try anything. except in reverse. Pick up 2, 3 or 4 gears in a handfull, and drop the same depending on the grade.
     
  9. crazycanuck

    crazycanuck Bobtail Member

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    Sounds like a 15 speed with a deep reduction. You would shift up 1 to 5 in D.R. then4 and 5 in lo, then 1st in high and away you go. 1 to 5. Or you could cheat when heavy. 1st deep reduction, out and into 1st low, then run it up as a 10 speed.
     
  10. crazycanuck

    crazycanuck Bobtail Member

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    All 18's are sluggish dropping from high to low range. Just make the drop 100 rpms earlier than most and take your time crossing the gate. It's not you.