48re shifting error!

[HAkers]

my 04 305 HO will "collapse" to 3rd or 4th gear directly from 1st, just as I crest a steep hill under heavy pulling situations... going camping with my 10K 5er up that grade into yosemite valley in summertime etc... It hits so hard you'd think you were rearended! Yes I'm in tow/haul. Doesn't do it empty. Shop couldn't find anything abnormal at transmission oil change. I don't have guages. I think it's software confusion. Torque management maybe?

I'm about to take to another dealership, they warned me unless they can reproduce it, I'm outta luck.

Any ideas ?





2004 QCSB HO 48re cool tube and TAG, otherwise stock 53K odo.

05 Mckenzie 5thwh 32 Ft triple bunks.

 

[MTollman]

I have had that with my 04. 5 but only with the troublsome Triple Dog loaded. Same exact thing only loaded under power and it feels like the motor just lets go. In totally stock mode it shifts very strangley with a lurch into OD. It always has since day one and dealer says no problem. Yea right... I love Cummins but I will never get an auto again. I had a 03 dually with manual that wasn't very fun to shift but I had no problems either. Try asking the dealer for the latest ecm flash. You might have to lean on them for it.

Good luck!

 

[Whiskey]

I would switch out the oil and *completly* fill with Synthetic.



whiskey

 

[HAkers]

thanks.

I petition for a new flash.

 

[PGreenleaf]

You must realise to start with you don't really have a tow haul on that 04. Although it says tow haul all your doing is locking out 4th when you hit tow haul. Its not like the 05 and newer tow haul modes. When your pulling a grade like that , if you cant pull it in third you should get your speed right and manually put your shifter into second, before its forced to do it by itself automatically. Then settle down at half throttle RPM about 2500 and sail right to the top . You gotta drive that trans or you wont have it long.

The 04 48re is capable of torque converter lockup in second but only if you have the gear selector in second.

 

[HAkers]

wow! I had no idea. thanks for the heads up. Any where I might read up on this transmission of mine?