GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

80e Swap Shifts great but a little strange at WOT 2-3 shift?

Thread Tools
 
Search this Thread
 
Old Jul 13, 2015 | 10:57 PM
  #1  
lxcoupe's Avatar
Thread Starter
TECH Fanatic
iTrader: (9)
 
Joined: Nov 2004
Posts: 1,127
Likes: 22
From: California
Default 80e Swap Shifts great but a little strange at WOT 2-3 shift?

Have about 2k daily driven miles on my craigslist 80e, Trans Go HD2, and Circle D 2B 258mm. Bone stock 5.3L motor with segment swap. The trans shifts perfectly, other than a small problem which I believe is tuning related (it has done this from the beginning of the swap). At WOT in 2nd gear, at ~4k rpm, it feels like the clutches disengage for a second or two, then re-engage. It definitely feels like a tuning issue. I do have TM removed and shift times set to .200 other than that I have not messed with anything. Any ideas? I found this video on youtube that is vaguely similar:

Reply
Old Jul 13, 2015 | 11:06 PM
  #2  
Fast355's Avatar
TECH Enthusiast
15 Year Member
Liked
 
Joined: Oct 2006
Posts: 642
Likes: 21
From: Euless, TX
Default

Sounds like it might be torque converter clutch related.
Reply
Old Jul 13, 2015 | 11:09 PM
  #3  
lxcoupe's Avatar
Thread Starter
TECH Fanatic
iTrader: (9)
 
Joined: Nov 2004
Posts: 1,127
Likes: 22
From: California
Default

Originally Posted by Fast355
Sounds like it might be torque converter clutch related.
As in a mechanical problem or tuning?
Reply
Old Jul 13, 2015 | 11:25 PM
  #4  
GMCtrk's Avatar
TECH Senior Member
iTrader: (27)
 
Joined: Jul 2004
Posts: 12,275
Likes: 17
From: Dallas
Default

sounds mechanical to me
Reply
Old Jul 14, 2015 | 12:57 AM
  #5  
lxcoupe's Avatar
Thread Starter
TECH Fanatic
iTrader: (9)
 
Joined: Nov 2004
Posts: 1,127
Likes: 22
From: California
Default

Originally Posted by GMCtrk
sounds mechanical to me
Hmmm, I've read a misfire can mess with the tcc. I wonder if pinging could do the same thing? I've been putting junk 87 gas in this thing since day 1.
Reply
Old Jul 14, 2015 | 07:15 AM
  #6  
03sierraslt's Avatar
Admin
iTrader: (22)
 
Joined: Jul 2004
Posts: 19,007
Likes: 221
From: Western PA
Default

Post up your TCC table. Or just the whole tune.
Reply
Old Jul 14, 2015 | 10:40 AM
  #7  
Fast355's Avatar
TECH Enthusiast
15 Year Member
Liked
 
Joined: Oct 2006
Posts: 642
Likes: 21
From: Euless, TX
Default

Originally Posted by lxcoupe
As in a mechanical problem or tuning?
I am thinking tuning as every stock 4L80E tune I have seen locks the torque converter in 2nd gear and then unlocks it again before the 2-3 shift or keeps it locked.
Reply
Old Jul 14, 2015 | 11:43 AM
  #8  
03sierraslt's Avatar
Admin
iTrader: (22)
 
Joined: Jul 2004
Posts: 19,007
Likes: 221
From: Western PA
Default

Sounds tune related to me also.
Reply
Old Jul 14, 2015 | 01:05 PM
  #9  
lxcoupe's Avatar
Thread Starter
TECH Fanatic
iTrader: (9)
 
Joined: Nov 2004
Posts: 1,127
Likes: 22
From: California
Default

Thanks for the replies guys, I do appreciate it. I should mention that other than this issue the trans is literally flawless. It has never seen north of 140 degrees and never once clunked/ slipped did anything that would suggest something mechanical. It could be VSS related? The speedo as well as my Aeroforce are dead accurate though when compared to an iPhone GPS signal. Here are my TCC and VSS settings. I also read that when I do the segment swap I needed to swap over the Trans diagnostics? I don't remember if I did that.

Name:  tcc.jpg
Views: 811
Size:  1.17 MB
Reply
Old Jul 14, 2015 | 01:06 PM
  #10  
lxcoupe's Avatar
Thread Starter
TECH Fanatic
iTrader: (9)
 
Joined: Nov 2004
Posts: 1,127
Likes: 22
From: California
Default

Originally Posted by Fast355
I am thinking tuning as every stock 4L80E tune I have seen locks the torque converter in 2nd gear and then unlocks it again before the 2-3 shift or keeps it locked.
This is 100% what it does. It doesn't feel violent, and the 2-3 shift feels real good. It just feels like someone cut the power for a second or two.

Also, how do I attach a file to the thread?
Reply



All times are GMT -5. The time now is 11:05 PM.