No 2-3 shift at WOT only??
08-18-2007, 12:41 PM
#1
No 2-3 shift at WOT only?? Anyone have any ideas for this one? I just installed a TR230 cam and since then I have no WOT 2-3 shift. It shifts fine at part throttle and holds fine in all the gears, but as soon as it tries to shift from 2-3 at WOT, it just starts banging the rev limiter. Before the cam install, I had zero issues. I've tried shifting it anywhere from 6000 to 6500 RPM's with the same results. Anyone know what this could be?
08-18-2007, 12:58 PM
#2
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Time for a rebuild. You're blowing through the high gear clutch pack, it simply cannot hold the power. It's usually the first issue in a 4L60e, and easily the most common.
08-18-2007, 01:13 PM
#3
Why will it hold it on a downshift? If I'm cruising at ~70 MPh and go WOT, it will downshift without any problems and hold fine all the way through 3rd. It just won't upshift. I had the tranny rebuilt this past spring (nothing special...just to get me through the year, so no surprises that it won't hold power).
08-18-2007, 01:26 PM
#4
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You might want to scan the thing looking at the applied force
motor current, commanded shift pressures etc. There is some
stupid stuff in stock tunes like the highest-line% in the force
motor table commanding max current, minimum actual line
pressure where you need the opposite. Somebody who goes
and "improves" the tune by commanding (shift pressure +
modifier tables) more than 96%, and opens up the max line
limit to let happen, would let you step right into that "hole"
if that table was left alone.
If you see line pressure is commanded high but force motor
current is also high this is your bug. Low force motor current
and still not holding, that's rebuild time.
motor current, commanded shift pressures etc. There is some
stupid stuff in stock tunes like the highest-line% in the force
motor table commanding max current, minimum actual line
pressure where you need the opposite. Somebody who goes
and "improves" the tune by commanding (shift pressure +
modifier tables) more than 96%, and opens up the max line
limit to let happen, would let you step right into that "hole"
if that table was left alone.
If you see line pressure is commanded high but force motor
current is also high this is your bug. Low force motor current
and still not holding, that's rebuild time.
08-18-2007, 07:34 PM
#6
I believe that you might be having a tuning issue. Your stall converter with the cam might very well be what is causing this. If you can not fix this through the tune give me a call if you still have my #. If not I will be in on Monday. Take care, Vince.
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08-20-2007, 01:27 AM
#11
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My car did the same thing. went 13.6 hitting the 2-3 limiter on every pass with mods in sig, 3 months later the trans is just starting to slip in the high RPM's and the car ran a 14.8 @ 95 on the only pass I made due to not wanting to eff anything up worse than it is 
Car is done for the season, When I come back from school in the spring it gets a built trans and a converter so not all bad is coming from this 
Car is done for the season, When I come back from school in the spring it gets a built trans and a converter so not all bad is coming from this
08-20-2007, 10:24 AM
#12
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Looking at the shift pressure line, you might want that "all in"
by whatever the Delivered Torque number is for WOT. Not that
the number is necessarily a good number anymore, with the
mods, and this may be part of the problem; more torque than
the PCM "thinks", less than max available line applied, slip it?
Still want to see the actual command chain of line pressure
commanded, force motor current applied across that shift
just to be sure, along with the Delivered Torque - Trans so
you know where you're playing. Maybe log the shaft speeds
too, so you can see where the slip is (converter, gearbox).
by whatever the Delivered Torque number is for WOT. Not that
the number is necessarily a good number anymore, with the
mods, and this may be part of the problem; more torque than
the PCM "thinks", less than max available line applied, slip it?
Still want to see the actual command chain of line pressure
commanded, force motor current applied across that shift
just to be sure, along with the Delivered Torque - Trans so
you know where you're playing. Maybe log the shaft speeds
too, so you can see where the slip is (converter, gearbox).
