Overdrive disconnect??

4cyl with auto 2012, I occasionally will haul or tow. Is there a way to lock out overdrive in these instances. I have been just keeping it in 3rd which works well but would like to keep it in 4th without going into overdrive. I can keep the rev's at about 2500 at a little below 60mph which for me is a great hauling and towing speed but was wondering about being in fourth and possibly bringing the rev's lower. Up until now I wasn't sure if it was a four speed with overdrive but on a run today I was doing a small climb on the high way and it shifted out of overdrive, I then placed it into 3rd. and it shifted down again. Thanks in advance for your help.

 

^^ yep,
You're still in 4th gear. I see it all the time with the 5 speed auto.
After cruising along at a steady speed, I hit a slight hill and the rpms rise. Just the torque converter unlocking and the engine spinning faster than the tranny. It's normal.

 

Thanks, I'll keep it in third. Much better not going in and out of overdrive.

 

The question is do you have the 4 or 5 speed auto. I am assuming by the way you are describing things, you have the A340, which is a 4 speed auto. Toyota spec shows your TCC lockup under normal driving occurs when in D4 between 44 and 47 mph, and in D3 it will occur between 44 and 47 mph as well(assuming 5% throttle). It will normally disengage at 40-43 mph in both D4 and D3. Shift points are as follows when at full throttle:

1. 1-2 37-44 mph
2. 2-3 74-80 mph
3. 3-4 95-103 mph

 

4 speed auto, thanks.. D 3 2 1 Talked with many people with the same set up and was told to stay out of D when hauling or towing. Its been working great for me. Rolls up and down most grades without shiffting and revs stay about 2500 or so at around 58 -60 mph. with not struggle at all.

 

Driving out of "overdrive" is an old school wives tale that started many years back. Todays transmissions are more robust, and the software for pressures and shift patters are much better than they used to be. As mentioned, unless you are actually having TROUBLE with shift hunting or jumping in and out of gear all the time, you will be perfectly fine with towing in "D". I have towed from small trailers to large goose necks using a variety of trucks and have never had an issue with towing in "D".

 

Here in Vermont with the many hills and mountains I did find it hunting a little more than I would have liked. I did pick up some mpgs leaving it in third. Of course when I travel down south I'll use drive since the trip is predominately flat.