Automatic shifts to soon

Lostcause

Member

May 27, 2004

81

1

9

Homestead Fla.

Feb 1, 2013

#1

• Feb 1, 2013

• #1

Hello everyone, I have a 91 mustang GT automatic. My problem is when I leave the car in drive and floor it first gear shifts at about 3100 RPM's, second gear not even that high shifts right away into third. If I manually shift the car using the 1-2-1 method it holds on to the gears all the way through. Any help for fixing this problem will be greatly appriciated. Thank you all in advance.

 

mikestang63

SN Certified Technician

Aug 27, 2012

11,606

8,859

214

In the garage

Feb 1, 2013

#2

• Feb 1, 2013

• #2

check your TV cable. A misadjusted cable can fry a transmission in a very short time. Make sure the plastic bushing is not broken. I would recommend replacing it with a brass bushing and clip. If you are not comfortable with this take it to a transmission shop where they can adjust it by the pressure.

Here is a video for reference.



By the way, the easiest way to burn out an AOD is to do the 1-2-1 shuffle.

 

Reactions: 88LX5.Oh

W

werner

New Member

May 1, 2012

10

0

1

Feb 4, 2013

#3

• Feb 4, 2013

• #3

Would a c4 be adjusted the same way ?

 

88LX5.Oh

15 Year Member

Dec 30, 2011

1,442

204

94

Arkansas

Feb 4, 2013

#4

• Feb 4, 2013

• #4

werner said:

Would a c4 be adjusted the same way ?

Click to expand...

C4 doesn't have a throttle pressure set up like the AOD. C4 has an internal governor that uses the centrifugal force of the output shaft spinning to dictate line pressure/shift points.

 

ratio411

Founding Member

Apr 21, 2002

3,870

73

109

Pensacola FL

Feb 4, 2013

#5

• Feb 4, 2013

• #5

werner said:

Would a c4 be adjusted the same way ?

Click to expand...

The c4 decides on it's shift points through 2 ajustable inputs.

One is the modulator valve, which is vacuum operated, and is adjusted with a tiny flat tip screwdriver in the vacuum nipple.
The other is a primative form of the TV cable, which is called a "passing gear" or "kickdown" arm.
You can adjust the arm to set your desired downshift point, and it also acts to keep the tranny in it's gears longer when you are driving aggressively. If you are driving easy, the kickdown is not operated, and the tranny shifts to your modulator adjustment.

Not to mention that the c4 has individual detents for each gear, so it can be manually shifted as well without trickery.

 

88LX5.Oh

15 Year Member

Dec 30, 2011

1,442

204

94

Arkansas

Feb 5, 2013

#6

• Feb 5, 2013

• #6

88LX5.Oh said:

C4 doesn't have a throttle pressure set up like the AOD. C4 has an internal governor that uses the centrifugal force of the output shaft spinning to dictate line pressure/shift points.

Click to expand...

Since I don't like to give out incomplete/wrong information, I might want to add that the AOD ALSO has a governor setup, but it used in conjunction with the TV set up. And Ratio basically covered all the rest lol

 

MFE92

10 Year Member

Aug 25, 2010

1,094

372

124

Phoenix

Feb 5, 2013

#7

• Feb 5, 2013

• #7

It's usually because the $2 grommet that attaches the cable to the throttle arm is broken and missing.