Explain my shifting...
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Fleet Mechanic
Joined: Feb 2004
Posts: 1,816
Likes: 3
From: River Valley AR
Explain my shifting...
When driving my truck in my sig, it feels like it has a 5 speed auto. I know that it is a combination of the truck shifting gears and the t/c locking and unlocking, but in what order is it doing it? For example:
1st gear t/c unlock
1st gear t/c lock
2nd gear t/c unlock
3rd gear t/c unlock
OD t/c lock
Would that be even close to what's actually happening? I know that from a stop i can see and feel the tach drop 4 times, once for each upshift. The main reason I'm asking this is because my truck feels strong and good when it shifts out of a gear at 2500 or so and gets into the next gear at 2100 or so. The problem is that one of the shifts is happening at about 2900 rpm (past the powerband) and gets the next gear at about 1800 rpm (under the powerband). I want to tighten the shifts up to get rid of this one late shift, but I don't know if it's actually changing gears or if the t/c is locking. Assuming that this could even be done, it makes me wonder if locking and unlocking the t/c in every gear would in effect give you an 8-speed tranny? (4 gears times 2 t/c possibilities) Maybe that's what some of these tranny controllers already do. Any thoughts on this?
1st gear t/c unlock
1st gear t/c lock
2nd gear t/c unlock
3rd gear t/c unlock
OD t/c lock
Would that be even close to what's actually happening? I know that from a stop i can see and feel the tach drop 4 times, once for each upshift. The main reason I'm asking this is because my truck feels strong and good when it shifts out of a gear at 2500 or so and gets into the next gear at 2100 or so. The problem is that one of the shifts is happening at about 2900 rpm (past the powerband) and gets the next gear at about 1800 rpm (under the powerband). I want to tighten the shifts up to get rid of this one late shift, but I don't know if it's actually changing gears or if the t/c is locking. Assuming that this could even be done, it makes me wonder if locking and unlocking the t/c in every gear would in effect give you an 8-speed tranny? (4 gears times 2 t/c possibilities) Maybe that's what some of these tranny controllers already do. Any thoughts on this?
Postmaster
Joined: Feb 2002
Posts: 2,773
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From: Bonney Lake, WA
Pocket said:
Bingo!! 
bodabdan- Since your truck is a '97, it's most likely a TDE0 or TDE1 box code, which are the codes that I have in my chip. Overall, the shift parameters are the most "user friendly", but there is a larger rpm drop when the t/c locks than any of the other shifts. There's nothing that can be done about that, though, except to space out the other shifts to match.
Correct me if I'm wrong, but I thought it was:
1st
2nd
3rd
t/c lock up
OD
1st
2nd
3rd
t/c lock up
OD
bodabdan- Since your truck is a '97, it's most likely a TDE0 or TDE1 box code, which are the codes that I have in my chip. Overall, the shift parameters are the most "user friendly", but there is a larger rpm drop when the t/c locks than any of the other shifts. There's nothing that can be done about that, though, except to space out the other shifts to match.
Thread Starter
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Fleet Mechanic
Joined: Feb 2004
Posts: 1,816
Likes: 3
From: River Valley AR
Thanks for the answer but I was hoping for a different one. The t/c lock in 3rd is what I'm feeling. I wish it felt like the other shifts, but I'll have to learn to live with it.
Quadzilla- When you say space out the other shifts are you referring to reprogramming the shift points? Eventually I will get and over/under drive unit and with a lower gear it might not feel too bad if the shifts were spaced out a little wider. but stock with 3.55's it would really be a dog if all the shifts were like that now.
Thanks guys-
Dan
Quadzilla- When you say space out the other shifts are you referring to reprogramming the shift points? Eventually I will get and over/under drive unit and with a lower gear it might not feel too bad if the shifts were spaced out a little wider. but stock with 3.55's it would really be a dog if all the shifts were like that now.
Thanks guys-
Dan
