Inconsistent shifting...
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From: Near Philly,PA
Inconsistent shifting... This is driving me nuts guys. My car is tuned with the line pressure slightly bumped up.
The 1-2 shift is always firm. Now the 2-3 shift is lagging a bit. I know the flaws of the 4L60E(I've had enough 700r4's to know). Here is what's getting me. Sometimes it lags, sometimes it slips a bit and other times it shift JUST like it should.
I've also noticed on the days where it's not shifting great all the gears don't hit hard. Are the clutches going or do I have a pressure/solonoid problem?
Any insight would be great
The 1-2 shift is always firm. Now the 2-3 shift is lagging a bit. I know the flaws of the 4L60E(I've had enough 700r4's to know). Here is what's getting me. Sometimes it lags, sometimes it slips a bit and other times it shift JUST like it should.
I've also noticed on the days where it's not shifting great all the gears don't hit hard. Are the clutches going or do I have a pressure/solonoid problem?
Any insight would be great
i think you might have pressure problems i am going through the same thing on my car right now. sometimes it shifts and sometimes it hits the limiter and sometimes it even just slips all the way from 6700 to 7200 into the limiter we have an idea on how to get that fixed but we are gonna try it first so if it isnt the right way we didnt give out the wrong info!!! the differance i think it is actually completely differance is yours is still using the pressure module and i and a buddy of mine is using a vaccum modulater so ill keep you updated to let you know whats goin on
this is just my opinion
this is just my opinion
Teching In
Joined: Jul 2006
Posts: 42
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Same thing just developed in my 98. Line pressures are bumped and now if I go WOT it freewheels after hitting the revlimiter. Manual low and 2nd work okay, but at WOT it ALWAYS slips now. Driving normally its just fine.
Something tells me that the line pressures shouldnt be toyed with..
Something tells me that the line pressures shouldnt be toyed with..
There are soft and hard ways to fail. I've seen things
in the tune that guarantee a loss of pressure if you go
too high on commanded line % and open up the limit
value. Any time you mess with the trans tune this has
to be a consideration.
Now, there are two prime sources of variability in the
shifting. One is the adaptive shift time learning, it will
jack the pressure up and down to meet time goals. The
other is fluid temp, this affects the real pressure at the
business end relative to the regulator end. Hopefully
you have this under control, and can scan for the line
% / force motor current applied during misbehavior to
see if it's the tune starving it. If neither then you'll
have to look at hardware problems.
in the tune that guarantee a loss of pressure if you go
too high on commanded line % and open up the limit
value. Any time you mess with the trans tune this has
to be a consideration.
Now, there are two prime sources of variability in the
shifting. One is the adaptive shift time learning, it will
jack the pressure up and down to meet time goals. The
other is fluid temp, this affects the real pressure at the
business end relative to the regulator end. Hopefully
you have this under control, and can scan for the line
% / force motor current applied during misbehavior to
see if it's the tune starving it. If neither then you'll
have to look at hardware problems.
