Posted 2011-02-18 3:03 PM (#130471 - in reply to #130451) Subject: RE: duramax
Expert
Posts: 3853 Location: Vermont
Originally written by chadsalt on 2011-02-18 8:53 AM
Originally written by PaulChristenson on 2011-02-17 10:13 PM
Originally written by jackbrat on 2011-02-17 9:44 PM
Paul,
The tranny shifts down too low. That is the problem. I touch the brake for it to shift down, usually it isn't enough, so I touch the brakes again and all of a sudden I am in the red RPM's. These are around curves so I can't really hit the gas to pull out of the red. I NEED to slow down.
My 2007 and 2008 Duramaxes are the six speed and I personally have not experienced what you describe...How much weight are you pulling? Do you have the six speed or the five speed Allisons? Also, do you have the most current flash on your computer? You may want to get a SPEED BRAKE from Banks...http://www.bankspower.com/news/show/24-Banks-SpeedBrake I have hear that older Duramax owners have had good luck with that unit
Paul, if I understand correctly what she is experiencing is normal. On the 01-06 (IIRC) there is a dashed "red line" at 3200-4800 rpm, aka the grade brake rpm range. The solid red line beyond 4800 rpm is not to be entered. The dashed red line was removed (~06) due to this type of confusion from drivers. No bigger than her trailer is, the grade braking feature will provide more than enough slowing power....if allowed to operate properly.
Thanks for the clarification Chad....I have NOT seen the dashboards of the OLD Duramax units...
Posted 2011-02-18 8:06 PM (#130481 - in reply to #130451) Subject: RE: duramax
Elite Veteran
Posts: 610 Location: Northern CA
Chadsalt,
Thanks for the info on the older trucks. I practiced the other day with the trailer empty down-hill and I have learned to down-shift into like 2 gear right at the beginning of the de-cline. That way I have not already picked up too much speed. My next question is, will the Allison tranny still do the down-shift braking when NOT in tow-haul mode? It has done this before. I haven't noticed it every time but it has done this.( When not in tow-haul) And yes, I agree it probably works right ...If or when allowed to. That is why I am asking :)
Posted 2011-02-18 8:48 PM (#130483 - in reply to #130481) Subject: RE: duramax
Expert
Posts: 3853 Location: Vermont
Originally written by jackbrat on 2011-02-18 9:06 PM
Chadsalt,
Thanks for the info on the older trucks. I practiced the other day with the trailer empty down-hill and I have learned to down-shift into like 2 gear right at the beginning of the de-cline. That way I have not already picked up too much speed. My next question is, will the Allison tranny still do the down-shift braking when NOT in tow-haul mode? It has done this before. I haven't noticed it every time but it has done this.( When not in tow-haul) And yes, I agree it probably works right ...If or when allowed to. That is why I am asking :)
As previously posted, it will downshift when NOT in tow-haul mode, but will NOT downshift below 4th...NOT very much breaking effect at all...
duramax
