Vortec 454/4L80e HD swapped 1999 Tahoe OBS
- Thread starter bigfootchiro
- Start date
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bigfootchiro
Full Access Member
Thank you! Any information is appreciated, as always, so thank you for your input
swathdiver
Full Access Member
Not without a manual, sorry. I would hook it up to a Tech-2 and see what's going on when it acts up, otherwise, I'd have to look at a manual or find an expert. Didn't Randy just get a 4L80?
randeez
Full Access Member
Not moving yet.
You need to get some tuning done. After thinking about it, the trans needs to know tire size and gear ratio for shifting and lock up which I'm sure are wrong if you havent touched rv tune
You need to get some tuning done. After thinking about it, the trans needs to know tire size and gear ratio for shifting and lock up which I'm sure are wrong if you havent touched rv tune
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bigfootchiro
Full Access Member
Shifting and lockup, before this issue occurred, seemed to be perfectly fine. Shifting is still fine, even if I put it in 4th, but the problem arises when TC doesn’t lockup for a while, then kicks down to 3rd. Adaptive tables were cleared in the transmission, thinking it learned something new, and that did not change anything.
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bigfootchiro
Full Access Member
Bad news... the P1870 Transmission Component Slipping code is the TC. Guy at transmission shop (I was referred to them by a patient, and he has built and raced many cars) said he would recommend a rebuild anyway. Quoted me at $1700 out the door.
My question to you guys... if I were to rebuild it myself, what kits do you recommend? Deluxe, Master, etc? Also, I would prefer a slightly higher stall TC if going this direction. Seems like you can have all of the parts for around $400-$600 depending on which direction you go.
My question to you guys... if I were to rebuild it myself, what kits do you recommend? Deluxe, Master, etc? Also, I would prefer a slightly higher stall TC if going this direction. Seems like you can have all of the parts for around $400-$600 depending on which direction you go.
Tonyrodz
Resident Resident
To me--seems a little high--not crazy high tho. What parts do you get for the $1700?
mikeyss
Full Access Member
I thought the P1870 trouble code was just a 4L60 problem. When I had my 95 Impala SS, it always had this code pop up, and then it'd bang through the gears until I stopped and restarted it. From my understanding the sleeve that the Piston activating the TCC swells or something then the Piston can't operate the TCC and pisses off the computer. I didn't realize the 4L80 also had this issue.
When you get the trans apart, I am curious if you have the straight cut planetary gears.
When you get the trans apart, I am curious if you have the straight cut planetary gears.
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bigfootchiro
Full Access Member
He didn’t say exactly if it was a master or deluxe rebuild, but did say all new clutches, a couple upgraded parts (since there is a 24K/2 year warranty), TC, not sure if all new electronics, and labor.
I guess the 4L80 was known for having TC issues. From what you just said, my transmission does the same. When the PCM senses this fault, it goes into a fail-safe mode (not limp) where it increases line pressure to maximum, making sure everything is lubricated so it doesn’t break. If you shut it down, let it rest a few minutes, and start it up, it goes back to normal.
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bigfootchiro
Full Access Member
Got some LS injectors on eBay. They aren’t Delphi or Bosch, but they were the only ones that had a consistent amount of good reviews. They are a “Stage 1” upgrade, and are essentially 32lb injectors. I know it will be too much fuel without tuning, but that’s what the 0411PCM swap is for 
