trans not shifting through the gears while in 4 lo

[Joey D]

Like I said in 4lo the trans does not want to shift out of 1st gear, then once wound up it shifts hard. 2nd is all it will do no 3rd. I have not used 4 lo for a long time, no need so who knows how long it's been doing this.

 

[Joey D]

It has also been shifting slower lately. It slides into gear very smooth but it takes longer to do it. I have Heaths Tune in it, about 1 year old tune.

 

[Joey D]

Today I am gifted with a hard shift from 1st to 2nd under normal throttle.

 

[WarWagon]

Shift in and out of 4-low a few times - clear the corrosion off the switch contacts.

Look at the selector switch for the 4-low. It changes the rear trans speed sensor on my year for the 4 low range. Your year may be different.
Also check wiring and fuses.

The harsh shift is the transmission in protection mode. You likely have codes stored now. The condition may still exist with the harsh shifting and my guess is loss of the rear speed sensor. Is the Speedo accurate?

 

[Joey D]

I will check my speedometer to see to be sure. I will check the switch connector as well. Friday I tried 4lo just to check it before I went wheeling saturday and thats when It started. It wouldn't shift out of 1st gear while in 4lo. After shifting it in and out a few times it started working but not like it should, very late shifting.
I hit 2hi and then the hard 1st shift started.
I will move the shifter back and forth to see if it helps. Thanks for the info

 

[Joey D]

Speed is 3-4 mph off on the highway

 

[Joey D]

This stopped for a while and is now back to doing it.