When you say "check your electrical connections at the PCM and the trans",
would either of those areas be near where the pan was dropped and the filter
changed?

 

The ones at the PCM, no, but anything is possible under the hoods of these trucks. It could be bumped when you are filling the trans if you have a huge jug of fluid and you are standing on the passenger side. More likely if you put anything on the PCM like tools. I had a loose trans PCM connector that made the trans shift extremely hard and GMC charged $1000 to replace the pressure control solenoid when all it was was a loose connector all along (found that 4 months later). The ones at the trans? Maybe depending on where it was touched. My instinct tells me to check connections first since they cost nothing to check and are easy to unplug, clean and plug back in.

 

Passenger side front corner of the transmission case is the connector. The wire harness goes straight down into the pan and runs to the solenoids and fluid temp sensor. As mentioned, it's free to check connections.

 

First i would get your fluid checked because you only added 4 quarts, unless i missed the post that said you did already.


Temp sensor? did later models come with a temp sensors? im jealous.. lol

 

So he underfilled it or overfilled it? Which is it? Underfilled would cause it to slip, correct?

Temp sensor? Do these transmissions adapt to different fluid temperatures? I notice a difference in the way mine runs when it is cold vs hot. Could the 98 have one?

 

well... He added 4 and richphotos said it should have 5-6..

and ohh yeah that could be, i thought he meant a temp sensor for you to see in the cab of the truck. but yeah the transmission wont go into overdrive till it gets warmed up, so it could be a sensor for the computer.