Hello.
A little desperate on this one since I spent so much on a trans repair.
I've never experienced this before in my disco so that is why I'm concerned.
Just recently when driving uphill at medium speeds 20-35mph, the truck won't downshift to a lower gear to increase speed. It usually will shift into 2nd from 3rd when going up steep hills at this speed. It just hangs onto 3rd no matter what even if I got pedal to the metal. All gears shift normally in and out down hill and on flat ground. Just seems when its under more load, its not switching down to the lower gear.

The trans and torque converter were replaced 20k miles ago, plugs and wires 2k ago, moved to 235/75/16 from 235/70/16 500mi ago. All fluids on time and full.

This is strange to me because on hill in particular that I go up every morning, the truck will shift into 2nd when I give it a bit more pedal to help make the grade but now it holds onto 3rd. I'm not getting any codes, noises, idling problems, hard shifts. Just slower than usual speeds as a result of the lack of shifting and happens when the engine is at any temp.

I'm thinking its either the torque converter, New larger tire size not timed with the gearing, shift points, the plugs, or the trans speed sensor. Any thoughts.

By the way I live in the mountains so uphill usually means super steep. Like san Francisco steep with curves.

1996 disco sd
auto trans
167 k miles

 

Next time manually shift into a lower gear, does the trans respond?
Yes?
Have your downshift cable adjusted, thats not what its called, I'm drawing a blank right now, but the trans shop will know what you mean.

 

It does respond when you manually shift to 3rd. Just not quick changing when you step on it at any speed. Only shifting in and out of gears at their appropriate speeds. I'm getting around pretty well but I'd hate to have to go 15 mph to use 2nd gear uphill

 

I figured it out. The kick down cable disconnected from the throttle body. Just need to get the correct hardware to reconnect it to the plate. What a relief. Glad it wasn't a sized kick down cable

 

Thank you for reporting back.

2nd gear is good upto about 35mph.

 

after new linkage for the kickdown cable and a couple of adjutments to the mount, the old girl shifts better than ever. no more at speed shifting. shes all pedal now