Hi, I am new to the forums and could use some expert help. I have a 94 with a straight six and with an automatic. I started having problems with the transmission slamming into gear changes. Now it does not do this every time. But I would say it is happening more frequently. I will be driving and when it goes to shift it hits hard into the next gear. I am pretty certain it does this in all gear changes. Even when it down shifts it is pretty hard aswell. Like I said, its not everyday. Maybe every fourth time I use the truck, but when it starts it does it all the time until I park it and use it again.
I have checked the fluid and it seems to be ok. It was changed about 40,000 miles ago. If anyone has some advice, I would greatly appreciate it.

 

It probably has one or more codes stored in the computer. When codes are set the trans goes into limp home mode, which includes really hard shifts.

Have the codes read then we can help diagnose what's wrong.