Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

Strange 1-2 Shift

Thread Tools
 
Search this Thread
 
Old 01-06-2005, 06:45 AM
  #1  
Teching In
Thread Starter
 
Fastmax's Avatar
 
Join Date: Jan 2005
Location: Port Orange Fl
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default Strange 1-2 Shift

I have a 94 Corvette that just doesnt feel quite right on the 1-2 shift. The car has 70K on it. The problem is a bit difficult to describe but the following is the best I can do. Rather than the smooth continual feel of acceleration it feels as though the car pauses, lays down, or holds back for half a second before it makes the shift. When it does finally shift it seems fairly normal. It does this at all throttle settings. I tried increasing the line pressure and this causes the shift to firm up considerably (it chirps the tires this way) but doesnt really change the hesitation or pause at all. Suggestions? Explanations?
Old 01-06-2005, 08:02 AM
  #2  
TECH Resident
 
SteveC's Avatar
 
Join Date: Jan 2002
Location: Poway, Ca. where GOD and the sun always shines
Posts: 823
Received 29 Likes on 27 Posts

Smile

I am by no means any expert on anything automotive, however it sounds like your trans is slipping, maybe a worn out 1-2 band.

SteveC
Old 01-06-2005, 06:12 PM
  #3  
Banned
iTrader: (2)
 
jxaxsxoxn's Avatar
 
Join Date: Jun 2004
Location: Arizona
Posts: 873
Likes: 0
Received 2 Likes on 2 Posts
Default

Has it been doing this for a while?
You could enlarge the second gear feed hole in the valve body seperator plate, decrease second gear accumulator travel, decrease second gear servo travel.
How were you increasing line pressure?
Old 01-07-2005, 04:10 PM
  #4  
Teching In
Thread Starter
 
Fastmax's Avatar
 
Join Date: Jan 2005
Location: Port Orange Fl
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

It really doesnt feel like a slip. It does it at even very light throttle settings with very little stress on the gear. And with the line pressure up it goes in hard enough to chirp the tires even at full throttle. I was increasing the line pressure electronically thru the ecm. I am not sure how long it has been doing it, I have only owned the car a few months, it has been this way since I bought it. I talked to a tranny man today that told me it sounds like a 1-2 flair. (flare?) Can anybody explain that to me?
Thanks, Roy
Old 01-07-2005, 05:20 PM
  #5  
Banned
iTrader: (2)
 
jxaxsxoxn's Avatar
 
Join Date: Jun 2004
Location: Arizona
Posts: 873
Likes: 0
Received 2 Likes on 2 Posts
Default

Shift flare is when the rpm goes up during a shift, then go back down. The rpm should just go down.
Assuming everything is in good working order in the trans, a transgo shift kit will help.
Or just what I said above, decrease servo travel.You can do all the above with the shift kit.
Old 01-21-2005, 11:10 AM
  #6  
TECH Apprentice
iTrader: (1)
 
Silver02's Avatar
 
Join Date: Aug 2004
Location: Southern Cal
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Fastmax
I have a 94 Corvette that just doesnt feel quite right on the 1-2 shift. The car has 70K on it. The problem is a bit difficult to describe but the following is the best I can do. Rather than the smooth continual feel of acceleration it feels as though the car pauses, lays down, or holds back for half a second before it makes the shift. When it does finally shift it seems fairly normal. It does this at all throttle settings. I tried increasing the line pressure and this causes the shift to firm up considerably (it chirps the tires this way) but doesnt really change the hesitation or pause at all. Suggestions? Explanations?
I had the same problem but on the 2-3 shift. After reading lots of posts and the following consumer info page:http://www.drwtransmission.com/info.htm, it turns out that overfilling by about 1 quart can correct the problem. My car would hesitate before shifting and then hit the rev limiter. Lots of playing around with setting on my Predator could not help. Last night checked fluid level. I was about 1/2 quart low. I put in 1 1/2 quarts so now I'm 1 quart over. Now it shifts like a dream and I used the Predator to set the shift points. Other people have had the same luck.
Old 09-13-2005, 04:35 PM
  #7  
TECH Addict
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Hello everyone. Im having the same exact problem right now. Found this surfing for a solution. I'm going to try overfilling it, cant hurt. Anybody else learn anything or fix thier problem another way?




All times are GMT -5. The time now is 07:25 AM.