Heavy load downshift from 6th to 5th question

[Ace476]

I have a 2008 DRW 6. 7 68rfe 3. 73 loaded & guages (2100 miles on it).

Wife and I just retired and are on our first trip with our 14k 5th wheel to snowbird state TEXAS from Minnesota! (In Texas now. ) Retirement is GREAT!!

:-lafLove the truck! I do have a question about downshifting from 6th to 5th on a long pull uphill either normal/tow haul and manual or by itself. At around 65mph immediately after the downshift the rpms go from ~1600 to 2800 and in a couple of seconds to ~2200rpms. I am thinking the torque converter locks after the shift or something like that. Kind of scares me a little and has to be using more fuel at least and heat up the transmission. :{ All my previous vehicles just downshifted without the bump in rpms.

My brothers 07. 5 just like mine does the same thing.

Any ideas or is this "normal" behavior?

Thanks, you guys are great!! Love ya!!

 

[Hoefler]

Normal. Unlocks the torque converter to down shift and re engages it after. If it did not do it, you would break it. If it goes immediately back to lockup, you won't get any more heat, if not, it will heat up very quickly and head for fluid failure.

 

[Wolfy]

I do have a question about downshifting from 6th to 5th on a long pull uphill either normal/tow haul and manual or by itself. At around 65mph immediately after the downshift the rpms go from ~1600 to 2800 and in a couple of seconds to ~2200rpms... . All my previous vehicles just downshifted without the bump in rpms.

Admittedly I don't understand much about autos,... but how can anyone expect to go into a lower gear, at a given speed, ... without engine rpm going up? What is the point of the downshift, if the engine isn't going to be producing more power(i. e. , more rpm) to move the given load at the given speed?

 

[BDW]

I think he was more concerned with the drop to 2200 rpm. Mine does the same, Shifts to 5th and then T/C locks back for lower rpm.

 

[Ace476]

Thanks guys i guess the truck is acting normally.

Wolfy, I realize the rpm's need to go up on
down shifting to get power it was the short extra increase in rpms i was concerned with.