6 speed mack trans

A 6-speed is going to have a lot larger difference in RPM's from one gear to the next than a 10 or 13 speed.

http://macktrucks.com/assets/mack/Datasheets/Transmissions/Updated041508/T-306G1361303.pdf

There's a "shift chart" near the bottom of the .pdf, but basically you are going to:

Run 1st gear to 1800 RPM...it'll slide into 2nd at 1000 RPM
Run 2nd gear to 1800 RPM...it'll slide into 3rd at 1100 RPM
Run 3rd gear to 1800 RPM...it'll slide into 4th at 1150 RPM
Run 4th gear to 1800 RPM...it'll slide into 5th at 1200 RPM
Run 5th gear to 1800 RPM...it'll slide into 6th at 1300 RPM

Downshifting is the opposite...slow down until your RPM's are 1000-1200 RPM's and rev it up to 1800 to slip it into the next lower gear.

 

It's probably got a Maxidyne under the hood....wide power band suited for this type of transmission. Drive it like you stole it.

 

Drove some years ago. I remember you had to shift like a granny, nice and slow, or it would grind.

 

We used to have them hooked up to lowboy trailers at 135 000lbs.
There was very little up shifting on a grade.
When we got the 10 and 12 speed Mack transmissions we were over the moon.
I think they were okay so the straight trucks though.

 

drove many 2 stick sixes only one airshift six....shifter slow, lugger down low.....very good transmission once you get the hang of it you wont want anything else (IMHO)..old timers used to say you could eat a sandwich between gears ....it will help to pull your rpms down if you shift with the dynatard or jake on...

 

yep they are a pain for us that grew up on 10's and 13's and what not. like the man said shift eat a cookie and shift again,

 

We still have a lot of Macks with them, their not bad once you get the hang of them, run up the rpm and let it drop down to under 1200 then shift.