New Cummins Turbo Diesel User

[WWalters]

Recently I bought a new 2001 Dodge 2500HD standard cab ST truck. The truck has the Cummins Turbo Diesel with 5 speed; 3. 54 anti-spin differential; trailor tow pkg and camper pkg. I haven't driven a vehicle with a standard transmission in 3 years. In addition I've never driven a diesel until now. I need some help as far as when to shift gears. I've read the owners manual 3 times, cover to cover and the only item that I've seen on using the 5 speed is the statement " For acceleration at speeds at less than 15mph, 2nd gear is recommended. " Sixty percent of my driving is in city traffic at speeds ranging from 0 to 45 mph. The route to where I work has 13 redlights. The remaining 40% of driving is on the freeway. At present I'm upshifting, usually starting in first gear, at 2,000 rpm for each gear excluding 5th. I do not down shift at each light. Usually I just shift into neutral and coast. I have been downshifting when going around a corner or slowing down for a light and then speeding up. I tried downshifting once at 40 to 45 mph from 5th to 4th and I didn't rev up the engine. I had visions of wrecking a couple of synchronizers. I haven't been shifting into 5th gear until 40+ mph. Any help on this would be appreciated.

 

[Zacman]

shifting

I am certain someone will answer your question on shifting. The shift points on these trucks will most likely be 1k rpm per shift under moderate acceleration if you are empty or not pulling anything. Somebody correct me if otherwise

I drive an auto because like you spend 90% of the time in stoplight to stoplight traffic and the auto for me is by no means a hinderance. First gear in these trucks would be used most likely starting from a dead stop on a steep hill or trailer towing or loaded. My last std shift truck was a Toyota 4wd and downshifting was always used to shed speed in lieu of brakes. The same most likely could be said for the Dodges Ram Cummins too.

 

[Sageair]

I have a 2001 with the 3:54 gears and the six speed but the methods I use should apply to your five speed. I see no reason to start out in first gear unless you are really heavily loaded/towing or are starting out up a tree. Use whichever gear keeps you in the fat part of the torque range 1600-2200 rpm. A method I learned that results in really smooth shifts is to accelerate to about 2200 r. p. m back off SLIGHTLY on the throttle until you are neither pulling or decelerating then hold the throttle steady while you upshift to the next gear. You will get shifts that are smooth as silk. Pay attention to what road speed results from a certain r. p. m in each gear and accelerate the engine to that speed when down shifting. This will result in really smooth down-shifs and minimal clutch wear.

 

[MCummings]

I have a a 1998. 5 truck (24V) 5-speed with the 3. 55 rear-end.



As far as shifting RPMs go, Cummins says to keep the RPMs below 2K for economy and above 2K for power.

I personally feel that the optimal shift RPM is around 2,100+/-.



As for shifting into 5th gear, I always(okay, ALMOST always) wait till nearly 50MPH to go into 5th. The reason I wait has to do with the all to common, and popular 5th gear nut problem.

My truck has 77,800 miles on it, and still has 5th gear operating normaly.



I 90% of the time use 1st gear to start for two reasons,

1. Saves the clutch, so far 77K+ and clutch holds like no tomorow

2. Sounds really good rowing through the gears.





Congratulations on your new truck.





MerrickNJr