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2004 3/4 4l80 1-2 shift

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Old 01-07-2013, 03:26 PM
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Default 2004 3/4 4l80 1-2 shift

At wot, the truck I picked up today to replace my 01 that got crushed on Christmas, seems to hit the 1-2 shift like a double tap. Have not looked at the Trans mount but it does not do it on the 2-3 shift. Has 156k miles, wondering of there is a issue to be had so I can figure something out if the mount is good.
Old 01-11-2013, 02:45 PM
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Looked at the trans mount today, looks fine. Any chance of a carrier bearing causing this? I know the rubber insulation can go bad.
Old 01-11-2013, 05:52 PM
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Carrier bearing is worn pretty bad, hope that is it.
Old 01-11-2013, 07:47 PM
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A double bump would tell me one of two things. Either you have intermediate clutches or sprag that are damaged. Basically apply slip apply. Or you might have the TCC applying right on top of second gear.
Old 01-12-2013, 06:23 AM
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Well, wonder if hp tuners will see the TCC on the shift?
Old 01-13-2013, 07:54 PM
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Originally Posted by ZONES89RS
Well, wonder if hp tuners will see the TCC on the shift?
check all of the mounts and the carrier bearing
Old 01-13-2013, 08:05 PM
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You can use HPT to monitor slip, so you can see if slip RPM goes down then up then back down.
Old 01-14-2013, 06:24 AM
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K, I will try a carrier, but it has blipped rpm a bit on the 3/4 shift while accelerating normally twice. This Trans may just be beat.
Old 01-14-2013, 12:15 PM
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just go cut some doughnuts in it . . . if it holds . . . then it's not the clutches
Old 01-14-2013, 02:51 PM
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I've been beating it a bit, and it is still holding, but for how long...guess I'll see what happens.
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