Tranny shifting pre-maturely
#1
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Tranny shifting pre-maturely
Tranny was built less then 4k ago. at WOT my tranny shifts pre-maturely...At WOT the car oways shifted at 124mph to go into over drive now it shift into over drive around 94mph 1-2 it shifting at 3000rpms....any ideas on how to fix it?
#4
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On LS1s a TPS overvoltage at WOT will cause this kind
of behavior. I don't know about LT1s. Put the meter to
it and check your shop manual for what the fault voltage
max might be.
of behavior. I don't know about LT1s. Put the meter to
it and check your shop manual for what the fault voltage
max might be.
#6
LS1Tech Sponsor
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Actually no thats a comon misconception codes are not always set when sensors are wrong. The PCM only knows a ceratin range it should be in and if its not then you will get a code but if its reading within that range but not right for conditions a code may not be set .
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#8
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TPS=throttle position sensor. Easiest way to mess up
is over-aggressive bump-stop grinding, but bad ground
can also skew it.
On LS1s the TPS will set a code if it's over 4.75V for
more than 10 seconds (something like that). You may
not have that kind of time-over-target in street driving.
But any time it's over 4.75V it will immediately fall into
some self-protection modes like short shifting the trans,
code or not.
is over-aggressive bump-stop grinding, but bad ground
can also skew it.
On LS1s the TPS will set a code if it's over 4.75V for
more than 10 seconds (something like that). You may
not have that kind of time-over-target in street driving.
But any time it's over 4.75V it will immediately fall into
some self-protection modes like short shifting the trans,
code or not.
#9
TECH Fanatic
Thread Starter
my second question is the TransGo shift kit Stage 2 take an extra quart of tranny fluid? The only reason why i ask is after i go my car back i drove it around for about 2 weeks and i decided to check my tranny fluid. Well they over filled it by 1 quart, so i drained a quart out and drove it around. It drives fine but again at WOT it bangs goin 1-2 and 2-3. The sound is like some one is taking a hammer and taking one big hit when it shifts.
#11
FormerVendor
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With a 2300 stall the shifts will be more noticeable. As far as the 1-2 shift the amount of washers used in the 1-2 accumulator housing could be an issue. Also if the installer flipped the 1-2 acc valve and sleeve in the valve body or if you have a sticky 1-2 acc valve this can be an issue as well. I have seen many times when the installer is not familiar with this type of work. The last thing to look at is how large the 1-2 feed hole is in the separator plate. With a lower stall I would have probably went with a smaller hole providing that the other things I have mentioned are correct. Vince