tranny issue

[redneckroot]

The tranny in my 98 seems to act like it is either not shifting out of overdrive or the converter is staying locked when I come to a stop sometimes. When I try to accelerate the truck actually stalls. Its only done it twice so far so not sure if its mechanical or electrical side. It feels like driving a stick if you tried to start out in 5th gear. Any help would be great.

 

[redneckroot]

Anyone?

 

[Big Blue24]

If your truck is sluggish at takeoff, it might be in limp mode where it starts up in 2nd gear instead of 1st.

If the motor is stalling, it's possible that your torque converter is locking up in second gear for some reason and combined with a 2nd gear limp mode start, I could see it possibly causing the truck to stall.

Is the check engine light on? Or, if you have a code reader, does it have any error codes?

If you manually shift the truck to "L" does it take off better?

You could try disconnecting both batteries and turning on the headlight switch for about 30 seconds to totally drain all the juice from the electrical system and then turn off the headlight switch and reconnect both batteries. Sometimes a "hard" restart or reset to the electrical system will get the powertrain control module to reset to default and come out of limp mode.

 

[LAmiller]

Yeah sounds like a ground/PCM issue, unless your Overdrive solenoid is sticking? You could put a line pressure gauge on the overdrive port and see if it releases pressure at speed or if it the VB is keeping it engaged down to a stop.

Lavon

 

[redneckroot]

I will try killing the power for a reset first. It only did it twice and I haven't driven it much since. I wish I could describe it better but being the middle of an intersection the first time and pulling out into traffic the second I didn't have any time to try to diagnose it. I also haven't been able to make it do it again but would like to find out what is going on. Thanks for the info if anyone else has any other ideas let me know.

 

[redneckroot]

Didn't check governor pressure yet but did try to reset the truck. Didn't help. I can't make the truck have the problem it does it randomly. Right now it has a delayed 1st to 2nd gear shift then when the problem happens it seems almost like it is trying to be in two gears at once not sure? It does do it only under acceleration. When the problem doesn't happen it shifts and acts just fine, and holds power fine. Anyone have any idea what would cause this? I think it is electrical but then again I'm not an auto tranny guy.