Weak lock up on new converter
10-11-2013, 09:21 AM
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Weak lock up on new converter I've had my converter for near a month now, everything is great with it. Trans fluid still looks new after a bit over 3k miles and countless WOT endeavors and WOT launches at the strip.
But the lock up clutch, since the first time I drove the car, has been very weak. Say I'm merging into the freeway at 3500rpm 50 mph, if it tries to lock up, you just feel it pulling but not getting it to actually lock up. Ill have to let off the gss to let it engage. If I'm just cruising at 50 2500 rpm, the lock up won't be the hard jolt everyone else is a getting, it takes about a full second, maybe a second and a half, for it to lock up from 2500 rpm. Seems and feels like the clutch isn't grabbing enough. I can press on the gas during lockup and it'll slip about 75-125 rpm, and no that's not it unlocking. If it unlocked the rpms would flash up by about 1500. Big difference.
I was wondering if this is a problem with my line pressure or just a bad converter?
But the lock up clutch, since the first time I drove the car, has been very weak. Say I'm merging into the freeway at 3500rpm 50 mph, if it tries to lock up, you just feel it pulling but not getting it to actually lock up. Ill have to let off the gss to let it engage. If I'm just cruising at 50 2500 rpm, the lock up won't be the hard jolt everyone else is a getting, it takes about a full second, maybe a second and a half, for it to lock up from 2500 rpm. Seems and feels like the clutch isn't grabbing enough. I can press on the gas during lockup and it'll slip about 75-125 rpm, and no that's not it unlocking. If it unlocked the rpms would flash up by about 1500. Big difference.
I was wondering if this is a problem with my line pressure or just a bad converter?
10-11-2013, 05:05 PM
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Check the o ring on the input shaft. When installing my converter the first time I tore it and didn't realize it until I drove the car. When I replaced the o ring the lockup stopped slipping.
10-13-2013, 01:33 AM
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Would this cause some type of damage if driven on hard for a while? Car has a bit over 3k miles with a visit to the track, burnouts, etc since the install.. But I'll take it back to the shop and have them check it, hopefully they won't charge me anything for it..
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10-16-2013, 04:45 PM
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Stock tune does not command enough base line
pressure for small diameter lockup clutches - if
you scan you will see 0% on the highway. Don't
know just how high the pedal has to go before it
adds any.
And if you have any "TCC Slip Learning" going on,
the TCC duty can knock it down from the already-
too-low main line pressure.
Put TCC duty to 98% min, 99% max first. That will
eliminate the "learning" (meant to shed pump load
until "just barely slips").
If you still have trouble then reach into the Force
Motor Positive table, or touch up the General Pressure
stuff that bumps up line when TCC is applied (if your
vehicle has this supported - some do, some don't).
This was enough to get my fried TCI drivable even
after ruining the clutch with Trick Shift fluid. Not great,
but would hold on on-ramps and such where before
touching the tune it'd hoot and howl up mild grades
before popping the slip-code.
pressure for small diameter lockup clutches - if
you scan you will see 0% on the highway. Don't
know just how high the pedal has to go before it
adds any.
And if you have any "TCC Slip Learning" going on,
the TCC duty can knock it down from the already-
too-low main line pressure.
Put TCC duty to 98% min, 99% max first. That will
eliminate the "learning" (meant to shed pump load
until "just barely slips").
If you still have trouble then reach into the Force
Motor Positive table, or touch up the General Pressure
stuff that bumps up line when TCC is applied (if your
vehicle has this supported - some do, some don't).
This was enough to get my fried TCI drivable even
after ruining the clutch with Trick Shift fluid. Not great,
but would hold on on-ramps and such where before
touching the tune it'd hoot and howl up mild grades
before popping the slip-code.
10-16-2013, 10:04 PM
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Great info Jimmy, I guess I'll get a tune before anything else. I was trying to talk to Frost to see if he would do a trans only tune for me, if I garenteed my business for a full tune. I know just trans only is probably a waste of time for him.
So, most likely, this problem isn't from an inferior converter? Its a 10.5" unit. Not as small as the 8 and 9" ones but definitely not the 12" stock unit.
Hell tune wise I was wanting to minimize lock up, its irritating sometimes. Having it lock up while you're generously on the gas getting on the freeway is ridiculous. I really only want it to lock when I'm not really accelerating at all.
So, most likely, this problem isn't from an inferior converter? Its a 10.5" unit. Not as small as the 8 and 9" ones but definitely not the 12" stock unit.
Hell tune wise I was wanting to minimize lock up, its irritating sometimes. Having it lock up while you're generously on the gas getting on the freeway is ridiculous. I really only want it to lock when I'm not really accelerating at all.
