Here goes. Seems my beloved 1998 is having a new problem. It started today when shifting up from a light. It rev'd to the normal shift point and then beyond and slammed into the next gear. The next 2 shifts where pretty normal but not smooth. Anyone got an idea I would love to hear.

 

Sounds like tbe Tapcells are maxxed out. They are the learning part that tells the truck when to shift. If you downshift the truck manually you will max out the tapcells and the truck will shift hard until it relearns. I can't tell you how to fix it, but the dealer can reset the tapcells. If you let it go, it will take out the torque conv.

 

I would start by verifying that the Throttle Position sensor is operating propperly.

 

Do you have a code showing such as P1870?

 

Thanks for the replies. Its shifting normally now but I know that something is wrong. As per the codes, I don't have reader but I also don't have an engine light on to indicate any codes are there to be read. Probably a noob answer but I haven't had vehicles that had codes for years.