No forward gears

Dugan

New Member

Mar 21, 2007

47

0

0

Portage Mi

Jul 28, 2007

#1

• Jul 28, 2007

• #1

I've been on the site for a few months now but haven't posted anything. i have a 67 mustang with a 302 from a 68 and a c4 tranny. now to the problem.. i was driving around town with a friend and we stoped to switch drivers, when my friend put it in D it wouldn't move. there is a tube (vacuum?) that runs from the intake to the tranny it was disconnected, reconnected it and while i still had it jacked up i started it and put it in D and the wheels spun but after i let the car down i tried to drive it and it wouldn't move... any ideas?


i don't know if it makes a difference but..
it also has a manual/automatic valve body and a B&M quicksilver shifter

 

rbohm

Founding Member

Apr 12, 2002

6,698

550

204

tucson,az

Jul 28, 2007

#2

• Jul 28, 2007

• #2

that tube goes to a vacuum operated modulator valve. if that valve is dieing, you wont get any forward gears. reverse for that matter. also check you fluid level.

 

brianj5600

Active Member

Sep 19, 2003

1,964

2

39

Middle TN

Jul 28, 2007

#3

• Jul 28, 2007

• #3

I am not sure that is true. The modulator valve lowers fluid pressure under high vacuum. When they fail, you get full pressure all the time. It could cause a low fluid level since a ruptured diaphram will allow fluid to be sucked into the motor. The car would be smoking badly if this was happening. Low fluid could cause you symtoms.

 

1

10secgoal

Active Member

Dec 1, 2003

2,801

3

49

San Diego

Jul 28, 2007

#4

• Jul 28, 2007

• #4

That's right. The modulator controls the line pressure in the tranny and the shift points. The forward drum is not locking up. Whether it be from old clutches or a broken seal. No forward clutch pack means no forward gears at all. It's fixable in the garage if you can turn a wrench and read a book.

 

M

mustangdave

My rearend needs a stud and two nuts.

Founding Member

Feb 26, 2002

2,976

1

56

North Carolina

Jul 28, 2007

#5

• Jul 28, 2007

• #5

check your fluid while car is running.

 

p0prcksandc0ke

New Member

Apr 27, 2007

111

0

0

sacramento,ca

Jul 28, 2007

#6

• Jul 28, 2007

• #6

if you have money just buy a new transmision and while your at it you mite as well put a bigger engine in

 

enferno

Member

Jun 20, 2006

418

2

16

Jul 28, 2007

#7

• Jul 28, 2007

• #7

p0prcksandc0ke said:

if you have money just buy a new transmision and while your at it you mite as well put a bigger engine in

Click to expand...

he might as well buy a car that's complete so he doesn't have to **** with it anymore then huh?

 

p0prcksandc0ke

New Member

Apr 27, 2007

111

0

0

sacramento,ca

Jul 28, 2007

#8

• Jul 28, 2007

• #8

no thats the whole fun you and that would cost more

 

Dugan

New Member

Mar 21, 2007

47

0

0

Portage Mi

Jul 28, 2007

#9

• Jul 28, 2007

• #9

i was leaking transmission fluid before the problem began. i overfilled it by a little on accident and have since checked it. it is still a little over full. it does smoke somewhat out of the exhaust on startups and the higher you rev the engine

 

brianj5600

Active Member

Sep 19, 2003

1,964

2

39

Middle TN

Jul 28, 2007

#10

• Jul 28, 2007

• #10

If it was pulling fluid out of the mudulator it would be under high vacuum. With the throttle wide open it should all but go away. I think a rebuild is in your future.

 

mustangmike6996

5 Year Member

Nov 10, 2005

483

6

29

clinton twp, MI

Jul 29, 2007

#11

• Jul 29, 2007

• #11

you said you overfill it???? is the fluid cavitating? (bubbling)??? thats not good to be over full

 

Dugan

New Member

Mar 21, 2007

47

0

0

Portage Mi

Jul 30, 2007

#12

• Jul 30, 2007

• #12

i over filled it on accident, just the once no its not bubbling.

 

Dugan

New Member

Mar 21, 2007

47

0

0

Portage Mi

Jul 30, 2007

#13

• Jul 30, 2007

• #13

so i figured i might as well just replace the modulator valve since it was so cheap. i put it on started it up and still won't go forward

 

1

10secgoal

Active Member

Dec 1, 2003

2,801

3

49

San Diego

Jul 30, 2007

#14

• Jul 30, 2007

• #14

That's because your forward clutches are still fried.
You generally lose first gear first. Here's what mine looked like. But I still had 2nd and 3rd gear.

 

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