having an issue with the 2-3 shift @ WOT
Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy
having an issue with the 2-3 shift @ WOT Im a noob when it comes to automatic transmissions, so i apologize in advance lol.
Here's the story on it-
in november 2010 i ran it at the track with no issues. at the time i had the stock 2.73 gears and a 3400 converter with a shift kit and my buddy's tune.
added 3.42 gears and 90mm intake/ tb and had my buddy re-tune it for me. part throttle is fine. It will not upshift into 3rd gear at WOT at the track. Also if i go from a slow roll or dig on the street it does the same thing. 1-2 shift is fine and the car pulls hard all the way through 2nd but it wont upshift into 3rd @ wot. It will not shift unless i let off the throttle a little bit to let it shift, then i can get back on it and itll continue to pull hard
Now here is the weird part- When im cruising anywhere from 35-65mph and go WOT, itll downshift into 2nd gear and upshift into 3rd gear perfectly fine with no problems.
I took the car to a transmission shop where a friend of mine works. he hooked up the scanner and found no problems with it. We couldnt do a WOT pull, but he said if the trans had any kind of problem, it'd show up at part throttle
Im pretty sure i attatched the correct HPT file. Any ideas? All help is greatly appreciated
Here's the story on it-
in november 2010 i ran it at the track with no issues. at the time i had the stock 2.73 gears and a 3400 converter with a shift kit and my buddy's tune.
added 3.42 gears and 90mm intake/ tb and had my buddy re-tune it for me. part throttle is fine. It will not upshift into 3rd gear at WOT at the track. Also if i go from a slow roll or dig on the street it does the same thing. 1-2 shift is fine and the car pulls hard all the way through 2nd but it wont upshift into 3rd @ wot. It will not shift unless i let off the throttle a little bit to let it shift, then i can get back on it and itll continue to pull hard
Now here is the weird part- When im cruising anywhere from 35-65mph and go WOT, itll downshift into 2nd gear and upshift into 3rd gear perfectly fine with no problems.
I took the car to a transmission shop where a friend of mine works. he hooked up the scanner and found no problems with it. We couldnt do a WOT pull, but he said if the trans had any kind of problem, it'd show up at part throttle
Im pretty sure i attatched the correct HPT file. Any ideas? All help is greatly appreciated
Registered User
Joined: Apr 2011
Posts: 6
Likes: 0
From: Imported from Detroit
cause i had a similar problem but it was my first gear. and after pulling my hair out i went for a true tune and my shift point for first was not right and that was the problem. might not be the answer but thats the only thing i could think of.
Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy
yep, I think there are 2 tables for shiftpoints. upshifts and downshifts. they are good as far as mph/rpm goes. The 2-3 upshift is perfect when im on the highway and go WOT anywhere from 35-65mph. It only seems to have the problem when going from 1st gear. I notice it the most at the track since i can dead hook there. He even commanded the 2-3 shift earlier just to get it to shift, but it would still pull to limiter and not upshift when I'd go from a slow roll/dig
Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy
That the other thing, i had my friend use his transmission shop's scanner to look for any problems that i might have but he didnt find anything. Ill search the members list for him and send a pm. thanks for pointing me in the right direction 
I would see if you can get a log of the WOT 2-3 shift (or lack thereof) logging commanded gear to see if the PCM is commanding it. If it's commanding it, its a transmission problem, if not, its a tune problem.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I looked at your tune. The shift rpm looks like mine, normal for first and third but lowered for 2>3. Remember mph has to met first, thats why we need a log so we can see and exact reference of mph vs. rpm with the converter flaring. i also think the 100% column on the part throttle table should match your wide open stuff which it doesn't.
Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy
I looked at your tune. The shift rpm looks like mine, normal for first and third but lowered for 2>3. Remember mph has to met first, thats why we need a log so we can see and exact reference of mph vs. rpm with the converter flaring. i also think the 100% column on the part throttle table should match your wide open stuff which it doesn't.
mine does the exact same thing as yours,even on highway pulls,exactly like yours.
hooking from a dead stop it shifts fine from 1-2,but bounces a couple of times on the limiter when it shifts from 2-3.
hooking from a dead stop it shifts fine from 1-2,but bounces a couple of times on the limiter when it shifts from 2-3.
Move your rev limiter up!!. Where is it set?
90 percent of time I see this happen people have it set too low which affects the 2-3 shift. With the new mods and slow shifting with the trans you wil bang against it all the time
90 percent of time I see this happen people have it set too low which affects the 2-3 shift. With the new mods and slow shifting with the trans you wil bang against it all the time
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Looks like you've got a 6300 rev-limiter. I would bump it to 6500. Honestly, my stock trans would shift at 6450 but not at 6350. **** was weird but thats just what it would do.
Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy
I'm suspecting the 2-4 servo Thread Starter
Joined: May 2005
Posts: 1,449
Likes: 0
From: South Jerzy