silver_goat

mine does the same thing. It is always under mild acceleration unloaded. I do not think mine is 1st to 2nd. I believe mine is 4th to OD. It's last shift always seem to be delayed. Not like its not going to shift, just seems to take it longer if I am not hard on the GO pedal. Pointed it out to the dealer at delivery and the service guy said it was normal and they all do it. ( for whatever that's worth) It does not seem to be a problem. Mine runs like a bat out of "the BAD place".

silver_goat

I think in the early model of the 48 re there was a flash update available for some kind of shifting problem but I am not sure. I think the shifting pattern your seeing is normal for the 48 re. I am not tranny expert by any means. Maybe another member can chime in.

kayjh

[quote author=BIGCUMMINZ link=board=20;threadid=19967;start=0#msg187820 date=1064264356]
i have noticed with my 03 ho/48 r. e. that under really light load (but still accelerating) the shift seems very noticable, and the shifting process takes alittle bit longer. I am thinking it is because of the programming, or maybe it is the pressure in the lines. My buddy at work has the same truck and his does it to ???
is this normal for all of you or is it my truck and my friends truck. under normal acceleration it shifts great. i dont like how it shifts from 1st to 2nd sometimes tho i think it is a glitch.(read in a different post) BTW holw do i get the 1-2 glitch fixed? my truck was manufactered 8/03 thanks
[/quote]

Big,

I test drove a 2003 - 2500 QC HO/48re in July and wasn't impressed with the shift quality of the 48re. I found the 1 - 2 shift to be quite abrupt (borderline "jarring&quot compared to the cars I was used to. I ended up ordering an '04, which I just took delivery of. I was expecting to have to deal with a rough shifting automatic. No such problems (I am happy to report). My new truck shifts smoothly, although you can always feel the shift. The final shift into OD is very noticeable (but I think this has more to do with the tall OD ratio).

I was thinking that either the truck I test drove had a problem, ir DC made some software or valving changes for the '04 model year. Either way, I'm very happy. I'll post how the transmission shifts pulling a trailer in a couple of days if anyone is interested.

Hope you get to the bottom of your rough shift condition.

silver_goat

having owned both the 47re and the 48re, I like the 48 much better. Shifts are firm and positive. The 47 was a good tranny but at very hard acceleration felt soft like slush. I do have to admit that my 03 ho like to accelerate fast rather than easing into the it. ;D ;D ;D

Pickle

Yes, mine does the same. I don't find it objectionable, since it works very much more smoothly under load. I'm guessing that there is an engineering choice made in this.

MCummings

[quote author=silver_goat link=board=20;threadid=19967;start=0#msg187828 date=1064265008]
I believe mine is 4th to OD.[/quote]

If the '03+ 48RE trucks operate anything like the previous 2nd Gens 47RE's, then, You've got a shift pattern that goes like this,,
1-2-3(TCC lock)-4. When the TCC locks, that will feel like an extra gear.
I think there is some programing, and valve body changes that will allow 2nd gear lock-up now, but I am not sure when the PCM/ECM decide to lock in 2nd gear.

If your truck did shift from 4th to OD, then you would have a 5-speed.

Merrick Cummings Jr