I have a 01' 24v turbo 2500. Recently I have noticed that the truck does not want to shift at or around the 20 mph mark. I can press the accelerator down and the rpms go way up but no shift or increase in speed. But, if I take my foot off the accelerator , as if I were shifting manually, and then press back down it shifts fine and speeds up, rpm go normal and the succeding shifts are fine as well. Any ideas?

this conversation might help...good luck http://www.cumminsforum.com/forum/98-5- ... hread.html

Thanks mod9... I tend to be a bit weak on the transmission stuff... But I'm going to dig a bit more to see if I can find more info...

I have a 01' 24v turbo 2500. Recently I have noticed that the truck does not want to shift at or around the 20 mph mark. I can press the accelerator down and the rpms go way up but no shift or increase in speed. But, if I take my foot off the accelerator , as if I were shifting manually, and then press back down it shifts fine and speeds up, rpm go normal and the succeding shifts are fine as well. Any ideas?

thats what mine is doin but its a 97' 2500 but i dont know much but check the fluid first or could be the bands need to be adjusted but if you fine anythang just holler appriacate it!

I'm not sure if you actually have a problem or not. My 01 acts pretty much like that. Light load the auto will up shift earlier which sometimes I intentionally coax it to do for better mpgs. It upshifts later if more throttle is applied. I don't pretend to out-think the 'puter... I'm not sure the why's & where fores.Could it be the engine is colder? Lower temps, like Fall & Winter the CTD runs richer until operating temperature is reached & may affect the shift speed also. Just my thoughts.Russ

my tranny guy told me once that you need to warm up your tranny just like its good to warm up your motor.when warming up your motor push in that emergency brake and throw the tranny in neutral.that will warm up the tranny so the temp will be close before you hammer it to get into traffic. :thumbsup

just a odd question why would you have to put it in neutral is it because theres more pressure on it or more flow in it?

USMC.That was going to be question as well. In N, does it let the fluid circulate through more of the trans? I can do that while I'm letting it sit for the extra minute I let it run in the colder temps. At least until the heat grid stops cycling.Dave

I don't let any vehicle it since the 1960's. Reports then were that idling was actually bad for engines... I think running rich on the chokes would wash the cylinder walls. What I do do is start the vehicles as soon as I'm in. Actually, with the CTD, I sometimes reach in & start before climbing up. If the truck has not been started in a couple of days, it won't move right away (like this since new). I'm told the torque converters drain down eventually while sitting & need to get oil up. After a minute or 2 it'll move.During this time, I fasten my seatbelts, adjust the mirrors, heater controls, maybe radio or any othe count down to launch. I watch the ammeter to be sure it is charging, I watch the oil pressure until it levels off. Then I start driving gently, on local roads, at least getting some miles from the warm up fuel burned. I have 5 miles of 35 mph local roads before I hit the faster state route.Maybe I'm doing it wrong but I think it works.Russ

i am inclined to agree with flagmanruss. my grandpa who is an ase mechanic for ~20years told me when i bought my truck that our cummins has a carbon problem and it is associated with long idle periods. he said to not worry about cool down unless i've been pulling or a lot of highway. he's opinion was i shouldn't need more then 5min cool with load, none if empty. months later i read that the 24valves make the head cooler. later i read that UPS does not use warm up/cool down cycles for their fleets. but i have also read about people "burning" off their their carbon with sustained high egts or seafoam. not sure about any of this. just passing along info

Well now that you got to be careful with. There is 2 type of people normal and lead foot. The lead foot person more times out of ten will need to worry about cool downs.

sorry for not getting back till now..my tranny guy says when you throw it in nuetral it allows the pumps inside to activate.which in trade makes the fluid inside start to move due to the valves having to open up..in park nothing in the tranny moves(valves, plates ,fluid...ect).if you have a tranny temp gauge(like i do)you can see the difference between warming up in park and in neutral.give it a try and you will see.

Interesting... I need to put a trans temp gauge in Mom's truck and see what it doing like...