This truck will not downshift when you come to a stop. You must manually shift it all the way through and then it does fine. What is causing this issue? It will kick down into passing gear. Anyone know what is wrong?

 

Get it checked for codes. This is OBDI so codes are very easy to read.

Here is how to do it.

 

You can also get codes using the appropriate scan tool. I have used a Snap-On MT2500 on these for many years. Also, here is a very inexpensive one that should work for you:
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transmission oil smells burnt, I only can drive in reverse, is it fixable?

 

Everything is fixable.