Truck in sig with 3 axel 15000# tag trailer(enclosed toy hauler). 23k gross, in tow haul. When down shifting under load it will shift to 3k rpm then quickley shift down 500 rpm. When upshifting it wants to hang(ie. if you want 65mph you have to over shoot to 68 or so the let off to shift up.). This is all at 55 to 70 mph rolling hills and sligth grades. Is this normal.
Clark

 

Sounds normal to me. When you downshift, it will start by unlocking the torque converter. The RPM will increase slightly. Then it will downshift a gear. The RPM will make a big jump up. Then the converter will lock up again and the RPM will drop by 500. The same is occuring when you upshift. Pulling a heavy load it is much more noticeable than without, because the duration of the shifts will be longer- your foot is on the throttle harder and the transmission is trying to stay unlocked longer.

 

Thanks. I am kinda new to autos(how new can you be at 66) and it just seemed a little busy.
Clark

 

You're welcome. I haven't owned too many autos either.

 

That's normal with 3.73 gears towing heavy. That is why folks with auto's get 4.10 gears that tow heavy.