Classic Mustangs (Tech) Technical discussions about the Mustangs of yester-year.

C4 shifting question-help

Thread Tools
 
Search this Thread
 
Old May 4, 2009 | 07:43 AM
  #1  
cfd2bc's Avatar
cfd2bc
Thread Starter
2nd Gear Member
 
Joined: Apr 2008
Posts: 259
From: Kansas
Default C4 shifting question-help

I finally got my car on the road over the weekend. It runs great however the trans shifts really early. It does go through all of the gears and into 3rd. I do not have the kick down attached. I pulled it back and tied it off on the off position, I think. I did adjust the vacume modulator clockwise and that seemed to help a little. In 3rd going 45 mph I am turning about 4000 rpms.

Not sure what's going on?

Jeff
Old May 4, 2009 | 03:08 PM
  #2  
groho's Avatar
groho
4th Gear Member
 
Joined: Oct 2005
Posts: 1,195
Default

did you modify your tranny at all? Sounds like your tranny is shifting too late. Back off on the vacuum modulator screw so it shifts earlier, that's assuming everything else is working fine; idle, no vacuum leaks, etc.
Old May 4, 2009 | 03:19 PM
  #3  
fakesnakes's Avatar
fakesnakes
4th Gear Member
 
Joined: Sep 2008
Posts: 1,839
From: Connecticut
Default

45 mph at 4000 rpm is second gear. Sounds like it is not shifting into third.
Old May 4, 2009 | 05:41 PM
  #4  
cfd2bc's Avatar
cfd2bc
Thread Starter
2nd Gear Member
 
Joined: Apr 2008
Posts: 259
From: Kansas
Default

It sure feels like 2nd I agree. I think it is definitely going into 3rd though. I feel 2 shift points on acceleration. I haven't done anything to the tranny.

Last edited by cfd2bc; May 4, 2009 at 05:44 PM.
Old May 4, 2009 | 10:18 PM
  #5  
cfd2bc's Avatar
cfd2bc
Thread Starter
2nd Gear Member
 
Joined: Apr 2008
Posts: 259
From: Kansas
Default

The vacuum line to the modulator is coming off a tree on the rear of the manifold. Is this the right spot?
Old May 4, 2009 | 11:35 PM
  #6  
67t5ponycoupe's Avatar
67t5ponycoupe
5th Gear Member
 
Joined: Jan 2006
Posts: 3,946
From: Colorado
Default

that vacuum should work. I would recommend getting that kick down hooked back up because I don't think it can be going into 3rd. 4000rpm at 45mph sounds like 2nd.
Old May 5, 2009 | 06:20 AM
  #7  
cfd2bc's Avatar
cfd2bc
Thread Starter
2nd Gear Member
 
Joined: Apr 2008
Posts: 259
From: Kansas
Default

So not having the kickdown hooked up could cause it not to go into 3rd? Also, is the kickdown electric? Does it work off of the neutral safety power? I messed with the kickdown and it seems to be spring loaded to a center spot. I can pull it back off that spot but it will return when I let go. I can also push it forward and it will return. it only moves about 1/2 an inch or so. No mechanical feel at all, smoothe.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Thunderball
4.6L (1996-2004 Modular) Mustang
15
Nov 22, 2015 11:49 PM
UrS4
S197 Handling Section
10
Oct 3, 2015 06:23 AM
Explosive
Street/Strip
17
Oct 2, 2015 07:45 AM
Mustangmalo
General Tech
2
Sep 6, 2015 05:22 PM




All times are GMT -5. The time now is 10:01 AM.