c5 auto trans shifting (Merged)
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1st Gear
Joined: May 2007
Posts: 1
Likes: 0
c5 auto trans shifting (Merged)
i have a 1998 vette automatic with 43k miles trans shifts at a higher rpm and slams into 2nd. When starting from a stop it accels in first gear then slams into second then 3rd gear. Seems to be at a higher rpm and the rough shift from 1st to2nd and 3rd. old this is the way this trans works. plan on going to vette dealer for help. but want to put this out so i can talk about problem a little smarter now. dennis
Last edited by Vetteman Jack; Apr 9, 2017 at 09:26 AM.
Drifting
Joined: Apr 2007
Posts: 1,517
Likes: 159
From: Lafayette Louisiana
What conditions are you talking about? Normal acceleration, Hard acceleration, WOT?
My 2004 A4 surely doesn't do anything I would describe as "slamming" into any gear.
If you take to dealer better have your BIG billfold!
My 2004 A4 surely doesn't do anything I would describe as "slamming" into any gear.
If you take to dealer better have your BIG billfold!
Drifting
Joined: Sep 2011
Posts: 1,424
Likes: 232
From: Licking MO
That is not right even at full throttle. It will shift firmly but not slam into next gear. Our 99 didn't and our 01 doesn't.
I used my diablo tuner to set the shift a lot firmer for a while and it was pretty harsh but not when stock.
I used my diablo tuner to set the shift a lot firmer for a while and it was pretty harsh but not when stock.
Le Mans Master
Joined: Sep 2014
Posts: 5,278
Likes: 539
From: Kelowna BC
I have a 1998 c5 only 152 were made with this sticker. I'm having a problem with the automatic trans. When starting from a stop it accels in first gear then slams into second then 3rd gear. Seems to be at a higher rpm and the rough shift from 1st to2nd and 3rd. Plan on taking to dealer. Would like to have a little info about subject before going to the dealer.
P.s.
Just bought the car and was to;d that's the way it is. I do not believe it
dennis
P.s.
Just bought the car and was to;d that's the way it is. I do not believe it
dennis
Seems to shift at a higher RPM than you think it should? And or harder?
Side note; 152 made with what sticker?
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
When a Gm auto trans is in reduced power mode or "limp mode" Th ECM sets the line pressure at max pressure which is 90 PSI both in P/T and WOT this full line pressure
is supposed to get you home---90 PSI at P/T will create violent hard shifts however
it does indicate that something is a miss -------There are several issues that can create a limp mode--Engine related or trans related---
Hard to diagnose-- If you feel some trans slipping during shifts it is most likely a failimg trans---If you feel no trans slipping then it can be an engine issue or simply an eng issue
Someone with a data logger can isolate what is the cause to see of it's a tuning issue due to aftermarket mods-----
PS the most common eng mod that creates shifting issues is an aftermarket MAF or a MAF with the screen removed---As the MAF sensor sets line pressure based on engine load read by the MAF
is supposed to get you home---90 PSI at P/T will create violent hard shifts however
it does indicate that something is a miss -------There are several issues that can create a limp mode--Engine related or trans related---
Hard to diagnose-- If you feel some trans slipping during shifts it is most likely a failimg trans---If you feel no trans slipping then it can be an engine issue or simply an eng issue
Someone with a data logger can isolate what is the cause to see of it's a tuning issue due to aftermarket mods-----
PS the most common eng mod that creates shifting issues is an aftermarket MAF or a MAF with the screen removed---As the MAF sensor sets line pressure based on engine load read by the MAF
Melting Slicks
Joined: Nov 2009
Posts: 2,922
Likes: 219
From: West Branch, MI
I have a 98 and it does not shift like that. It did not shift like that when it was stock, and I've since rebuilt it to handle 750HP and it does not shift like that either. It is NOT "the way this trans works". Couple of questions. Is this car stock? Did it shift this way when you purchased it? It could be a problem in the trans with something sticking then once it builds up enough pressure, it finishes the shift but a hard, high rpm shift. You can also program the trans to shift this way by setting shift points and how much pressure before the solenoids take you to the next gear (2nd in your case). GL with your fix... The dealership is going to tell you to repair/replace the tranny. It's just what they do. A Corvette shop with HP tuners could look at your tune and tell you what settings are being used in the trans.
Last edited by CactusCat; Apr 9, 2017 at 12:43 AM.
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My A4 '03 does not slam into gear with shifting. Have a good shop take a look at it - preferably one that is familiar with Vettes.
