Jump to content

How To Downshift 12 Speed?


mpnichols

Recommended Posts

First you have to remember the trans gears are always spinning the faster the truck is going the faster the gears are spinning,to down shift you need to raise the rpm of the engine to match the tran speed,when you get it just right the gears will mesh together. Practice makes perfect :)

Link to comment
Share on other sites

:SMOKIE-LFT: I don't know how to explain it to you any better. but let me tell you that once you master the Mack 12 speed it will be the best transmission you can have behind that E9 :SMOKIE-RT:

Thats pretty much it. if your shift change for going up gears is say a 400 rpm drop per gear change then for a down shift the rpm would be around 400 higher than your current rpm.

Grant

Link to comment
Share on other sites

Thats pretty much it. if your shift change for going up gears is say a 400 rpm drop per gear change then for a down shift the rpm would be around 400 higher than your current rpm.

Grant

Unless your just downshifting a whole gear with the stick, and not using the splitter, then it's about 900 RPM.

"If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

Link to comment
Share on other sites

  • 2 weeks later...
Need advise on how to downshift. Can't get into gear. I have purchased a 1988 RW713 Superliner E9 motor. Do not know the made of trans. It is a 12 speed w 4 air selection on the shifter ( H,D,N,R ). Upshifts fine.

It is a sweet tranny!!!

What I do if you want to downshift 1 gear from High to directs just take your foot off the accelerator and flip the splitter from High range down to direct range then push foot back on accelerator.

With my V8 12 speed I dont split a whole lot. Essentially if you have a lot of trouble shifitng and splitting(direct to high) then just shift it like a 5 speed. Unless there is a huge grade I wont split until 4th and 5th holes.

Hope this helps!!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...