Transmission???

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stutaeng

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Yes it was doing it then as well. I got it rebuilt but I would assume he should have put in a new tcc solenoid could it be a torque converter??? But I’m thinking it’s what u said an maybe he just reused the old one??? I’ll have to find out
Yes, exactly what I was thinking. That's why I asked. It's not the solenoid that's the problem, rather it's the bore/valve wear on the valve body. Again, I don't think it's actual torque converter itself. But since you mentioned TC, was a new/remanufactured TC installed?

Hopefully not that bad of fix. I'm pretty sure this can be corrected with the unit still on the truck. Just need to get the oil drained and pan dropped.
 

Jesse_Wenting

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It's a problem with the TCC regulator valve in the valve body
I’m thinking it’s what u said an maybe he just reused the old one
Replacing the wiring harness isn't a bad idea if it's never been done. I didn't do mine at first but decided to get it over with when I pulled it out the 2nd time. If there's fluid in the exterior connector then replacement is required plain and simple
 

Pinger

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Did it do that before it got rebuilt? Are you sure it's not the 1-2 shift?. I had a transmission that did the same thing. After getting off the freeway it did a harsh shift 1-2. Basically the ECU detects a problem and commands maximum line pressure all the time. That's the reason for the harsh shift.


Yes it was doing it then as well.

I had hard up-shifts (4L 80E) that was cured when I reinstated the missing fuse for the MAF sensor. Without the MAF sensor being in play, it as stutaeng says, 'commands maximum line pressure all the time'. I'm not saying that this is your problem but for the five minutes it takes to check the MAF sensor...
 

GMTMark

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The TCC valve works back and forth very quickly. Almost like a vibration. It’s supposed to allow a controlled slip of the tcc. The motion of this valve wears the bore and can cause your problem. Sonnax now offers a repair kit that doesn’t require a reamer. Transgo also offers a replacement valve for this. The same valve can cause the harsh 1st gear problem. Just have your builder check it out. If he’s trained he should know this common problem.
 

GMTMark

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Good question. I don’t know. All I can say is that one malfunction can affect a seemingly unrelated function. Sort of like the MAF sensor can have the same effect. Unplug your MAF and see how hard it hits. The tcc valve isn’t the only thing that causes this. Fluid level can be a factor as well. I’m not a 4L60e expert, just repeating what I’ve read and heard. I’m about to go through mine so I’ve been trying to get info on preventing these problems. I also have a good friend that has built hundreds of these things. I’m just now graduating from thm 350’s and 400’s.
 
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