All:
I had the TSB 037 done today and I must say I'm impressed Truck shifts better seems to run better and an increase of 3mpg on the overhead from 15.3 to 18.2 running 70-75 interstate toi work. If this holds true on a hand calculated figure I will be super impressed
Happy New Year All
Danny:

 

Hope to not get off track here... but have you noticed a stumbling shift from 3rd into 4th under 75% pedal or more? I've had mine to the dealer and they say that it's normal... but it just doesn't feel right.

 

I had the flash done. No difference in shifts or mileage. Still a rock solid 14.5mpg in mixed city/freeway driving hand calculated.

 

Mine does it terrible, it has done it from day one. I am just waiting for it to go and then in goes a goerrend or dtt tranny.

Heath

 

Mine starts better in the cold, runs quieter at idle, tic/knock is less, no smoke when cold and about 1.5 mpg better on the highway (hand calculated). Overhead is about 0.75 mpg over actual.

 

Glad to hear I'm not the only one with this lil problem then...

 

Had mine done a while a go did not notice a real difference in milage hand calc. Over head did rise quite a bit. I did notice that the truck does not accelerate as fast as before. I did email cummins and was told no loss in power because of tsb. I don't know if this is true.

 

shouldn't be a loss in power, contrary! flash puts the 600 motor to 610 ft lbs, as far as the funny shift to overdrive it happens way less often. the rest of the shifts seemed better and truck is much easier to keep in gear without dowshifting, can finally lug it a little bit as it seems greater right foot travel is needed to get it to downshift, most likely one way they are getting the truck to get better mpg.

 

From what I understand, it feels like less because it did something so that it is not putting it all down right away. I beleive there was a problem with drivline issues as well and this was part of it to help that.

 

I think that jerky shift is the tranny dropping out of L/U shifting up to O/D then locking back up, so you are not shifting 3rd to OD while locked up. Supposed to save on converter. If you watch the tach it will be doing a "double bounce" at the same time.

 

Yea, that's what the tech has told me... the tranny lockingin and then unlocking and then shifting. Just kind of an annoyance and doesn't feel right.

 

When not in towmode so the trans will shift into 4th , the trans wont go into lockup in 3rd, it shifts 1st 2nd 3rd 4th then lockup. If you put it in towmode then it shifts 1st,2nd 3rd, then lockup. with NO 4th.
So if your in towmode and it shifts 1st 2nd 3rd then lockup, and then you hit the button allowing it to go to 4th ,then you'll get the funny shift , as it will release 3rd lockup ,shift to 4th and then go into 4th lockup. Once you understand just what this 48re is doing you'll find it to be a nice worker. Also if you lock your gearshift back in 2nd, you will have 2nd gear lockup for pulling long steep hills and for downhill motor brakeing.

 

I get it w/o hitting the tow/haul and start going... about 3/4 throttle and about 50 or 60 and it'll do it.

 

I get it all the time every time, just used to it by now. How is this effecting longivity?