Tscape16

iTrader: (2)

Well, my '97 WS6 has been having a problem for a few years, but I have the money to fix it now if there is something wrong.

*It seems whenever I drive more than 40 miles on the highway at 70-75 then come back into town...no matter how lightly I accelerate, the car shifts hard. Like jerk you around hard. Normally to fix it, I pull in somewhere and turn-off the car, letting it sit for a few minutes. Then I take off and it is all good. Is my computer just messed up or is my tranny just crap? Thanks for any help/advice.

ZONES89RS

iTrader: (25)

Possibility of trash in the solenoids(i believe 4L60s have them). I had the problem with my truck, it would shift hard as hell. Replaced those solenoids and everything was fine. Mine would not operate as they should, i had 260k miles at the time.

sweet-94z28

iTrader: (30)

It sounds like there is a clog or something because its running higher line pressure to get that harder shift. You need to find what is creating higher line pressure to fix it. I would just get a rebuilt trans with some goodies in it. The 4L60's are junk stock and you need to beef them up a little to make them reliable and a little more fun anyway.

shbox

You need to scan for trouble codes. Most tranny codes don't cause the SES to come on. In the presence of many tranny codes the line pressure is increased. You would feel hard shifts when this happens.

the_merv

iTrader: (88)

Yea I would put a Scanner on it and see what comes up.

Tscape16

iTrader: (2)

P1870 - Transmission Component Slipping, but the light comes on only after driving like 40 miles...all highway so the same gear for the most part. So IDK if my computer is messed up or what. Like I said, it goes away after I sit for awhile.

sweet-94z28

iTrader: (30)

Have you changed the fluid lately. It might just be getting hot and causing a default. Old fluid heats up a lot faster. Does it feel like it tries to slip at all? Mine acted like neutral above 4K before mine was replaced.

djjab57

iTrader: (17)

i haven't read all the responses but mine was doing this and it was a clogged up filter, i changed it and it took care of the problem

Tscape16

iTrader: (2)

It never really slips...just firms up. My Tranny fluid was last changed in the summer of 2006 when I had some slight leaking issues. It has been doing this since probably fall of 2007 unfortuantly, but I normally don't highway 40 miles at a time so I normally don't have symptoms.

shbox

P1870 Transmission Component Slipping

Here are the default actions:

*DTC P1870 will be stored in PCM history
*Inhibit TCC engagement
*Inhibit 4th gear if in hot mode
*Freeze 1-2 shift adapts from being updated
*Maximum line pressure

Tscape16

iTrader: (2)

How do I fix that then. All I have is a reader.

shbox

You probably take it to a transmission shop and have it worked on. I am assuming it means the transmisison is internally slipping (or at least the computer thinks it is) and the default actions are taken to help keep it from slipping more.