4L60E goes into neutral at WOT
03-23-2012, 05:37 AM
#1
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4L60E goes into neutral at WOT OK, so I am at a bit of a loss here. I have an LQ series engine (it is supercharged) with 4L60E stock converter and DBW. If I progressively lean into the throttle everything works as expected with downshift. If I just mat the throttle the engine will RPM like crazy, the trans seems like it wants to downshift but the engine will just free rev and hit the limiter. If I back off the throttle it will recover. Any ideas?
So codes, trans does not leak, fluid level at full. Shifter is adjusted.
So codes, trans does not leak, fluid level at full. Shifter is adjusted.
03-23-2012, 06:52 AM
#2
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I've been told this happens when the tranny is getting up in age and the clutches are getting thin.
Basically, you're putting too much power to it for it's age I'd say. Is it a salvage tranny?
a supercharged LQ could easily be in the 500-600whp range. That's a lot of power for a 60, especially if it's not built, and especially if it's not fairly new.
Basically, you're putting too much power to it for it's age I'd say. Is it a salvage tranny?
a supercharged LQ could easily be in the 500-600whp range. That's a lot of power for a 60, especially if it's not built, and especially if it's not fairly new.
03-23-2012, 10:21 AM
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You want to scan, starting with the force motor current
while it's misbehaving. If current goes to zero and it still
can't hold, it's a fried trans. If current goes up to 1000+
milliamps, then this is a tuning screwup and the trans is
the victim, not the cause.
while it's misbehaving. If current goes to zero and it still
can't hold, it's a fried trans. If current goes up to 1000+
milliamps, then this is a tuning screwup and the trans is
the victim, not the cause.
03-23-2012, 08:13 PM
#4
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Here is what I can say about the trans. It is a take out of a salvage yard, 48K miles. I did drain all of the fluid when I took delivery, no chunks or debris in the pan, very little film either. The fluid is synthetic, does not smell scorched. I would have to think that this is a tuning issue vs. a dead trans, it just works too well aside from the WOT issue. I guess it is time for testing. What is the correct procedure to test force current motor?
03-28-2012, 08:21 AM
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Mine ended up being a cracked forward piston "twice" now with the exact same symptoms. Now I got Steels to replace the factory aluminum ones. My tranny will be done on friday so I am fairly fresh with this info. Mine did that, then It would slip a little before it went into first at a stop unless i manually did it. Then I did a hole shot and Kaplouwie It did't go much of anywhere. now it's gettin fixxed. Only good thing is now I'm gettin a Circle D 3800 stall so I'm excited. My problem may not be the same but if I were a bettin man....
Last edited by rpmatredline; 03-28-2012 at 08:22 AM. Reason: missspelling
04-01-2012, 08:13 AM
#7
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If this turns out that the trans is hurt I will probably look at going with a 6 speed (6L80 or 6L90). Anyone know about these? What about a compatible PCM to use with my 6.0.
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04-01-2012, 09:57 AM
#8
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iirc the 6L80E uses its own TCM, but you still need some conversion.
imo tho, after owning both, I'd say get yourself a 4L80e and be done with it.
these 6Ls shift too damn much.
imo tho, after owning both, I'd say get yourself a 4L80e and be done with it.
these 6Ls shift too damn much.
04-02-2012, 05:39 AM
#9
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Just a quick thought, the engine was originally backed by a 4L80. I have not actually had the PCM tuned for a 4L60. Are the base tunes similar enough to make the car drive, but far enough apart to cause my issues?
