66 Mustang 289 C4 Jumps into Reverse after Starting.

cturboaddict

Founding Member
Just picked up a 66 Mustang. Planning on rebuilding the 2 Barrel autolite 2100 this weekend, and checking timing, upgrading to Pertronix.

But noticed something last weekend that scared me a little bit.
When you first start the car, the car will move itself into reverse. If you didn't have your foot on the brake after you started it, it would essentially drive away in reverse.

Seeing that I'm working on timing and carb adjustments, for safety reasons, I feel this will need to be corrected immediately.

FYI- The interior and glass is all out of the car as it was supposed to go to paint next week. So there is no "shifter handle/button". You sort of have to pull the cable end at the end of the shaft and move the shifter handle into desired gear. (Don't know if this would effect this or not)
 
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GOvert

Active Member
Jan 27, 2007
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north central Tennessee Valley
One of the main two house rules at my Shop as it has to do with these ancient Mustangs is, If the engine is running, someone is in the drivers seat. I've had two C-4 automatics drop into gear on me in the past. The first time years back while out delivering phone books in the winter and left the engine running to keep the heater going, got out of the '66, walked up to someone's porch to drop the book, turned around and it dropped into reverse. Fortunately I had left the drivers door open and it took me about 75 feet to run it down and jump in the seat to stop it. It stopped just feet from a large brick mailbox and fortunately no one was passing down the street that it crossed. It happened to me again with a different 'stang one cold morning at home. I had started the engine, realized that I forgot my winter hat, left it running to run in the house, came out it was backing up towards the pasture fence. I ran it down too. (I was a much faster man on my feet two decades ago). I had to open the door this time and jump in. A similar thing happened to our Mustang club president after an inexperienced with old Mustangs repair shop had his C-4 out and back in. It drove itself out of his garage and backed into a tree. It fouled up the taillamp panel, bumper and trunk lid. After this happened we made a rule at the Mustang show that if someone had their engine running then someone had to be in the drivers seat. Now I jack up the backend and put it on stands if I am going to be working under the hood and periodically starting it
The other main rule that we have is we don't leave battery chargers unattended especially overnight. How do you sue China if a battery charger burns your car down?
We also have rules having to do with gasoline but I won't get into all of that.
Be careful. These vehicles can hurt someone if one is not in tune with everything going on while repairing them.
 

cturboaddict

Founding Member
Alright Fellas, Yes I can move the shifter side to side a bit, about 3/8" wiggle.
FYI- The guy I bought this from, said he only "bolted everything together quickly" as parts were all over his shop to sell it.
Anyhow, here are some photos of the Ball Doo Dad, shifter, kickdown linkage (which looks totally wrong to me), and the adjustment bolt. Also, a video to show what I think the problem is. When the car is in park, and the "detent ball for the shifter button" is down, I can literally grab the shifter rod and shift it into reverse.
Let me know where and what I need to do, much appreciated. And, is there a better setup for the kickdown linkage? Seems like there's an awful lot of cable there for such a short distance.
SHIFTER
View: https://flic.kr/p/2hikQDN

SHIFTER BALL DO DAD DOWN (locked into position, cannot pull it into reverse/N/D, but it does click into reverse when I pull hard in Park)
View: https://flic.kr/p/2hikQE9

Shifter BALL DO DAD UP (can cycle through all of the gears)
View: https://flic.kr/p/2hij8Le

KICKDOWN LINKAGE (looks like it's looped the wrong way or something)
View: https://flic.kr/p/2hij8MB

SHIFTER ROD ADJUSTMENT BOLT (It's pretty far back on the shaft)
View: https://flic.kr/p/2hikQDT

ROD ON TRANS
View: https://flic.kr/p/2himSFC

I'm GUESSING THIS IS THE NSS, as it's disconnected and I can start the car in Reverse. So that's not good.
View: https://flic.kr/p/2him8eB


Here's a quick video.... Any input is appreciated.
View: https://youtu.be/n50-a_yTtqU
 

horse sence

That $5 hooker turn out to be a guy
Mod Dude
Nov 29, 1999
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The t handle off the shifter will not cause a problem ,other than making it hard to shift .
If the shifter can be moved side to side ,the bushings are shot or gone . The aluminum piece the pivot bolt for the shifter arm can also be broken out
 

horse sence

That $5 hooker turn out to be a guy
Mod Dude
Nov 29, 1999
8,777
2,950
233
Wile Coyote's stunt double
Even with bushings replaced ,never trust it .
My brother was working on a 69 ,under the hood with it running ,i told him to atleast set the emergency brake . He revved it one more time and it jumped into drive and took out the post on the front porch . You have to realise the shifter is mounted solid in the floor ,but the transmission and motor are on rubber mounts and flex ,especially if the mounts are old ,it pulls on the shifter rod and if the bushings are bad in the shifter it can jump into gear .
He was lucky and at the side over the front fender
 
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GOvert

Active Member
Jan 27, 2007
259
42
38
58
north central Tennessee Valley
As far as the little ball on top of the shifter goes, if you can move it with your thumb and the little gate? moves up and down in the notches then that cable is in good shape.(Edited-I see now after re-reading that you said it was good). The black push button in the left side of the T-handle can easily be installed the wrong way. It will only work one way. As far as the "kickdown" cable goes, there are two ways that the arm that it is hooked to the throttle pedal assembly. Some were welded, some had a very small U-bolt attaching the arm to the throttle rod. A welded one could be bent out of adjustment and the U-bolt type could be loose or tightened down in the wrong position. Maybe a user here has the info on adjusting that, that they could share. If I was standing over it I could adjust it. However the basics of it are, it shouldn't have any tension on it until you press the pedal to the floor.
I remembered a 3rd situation where one dropped in reverse on me. It was V-8 powered and The coil wire was in reach to yank and shut down the engine. If it had been straight six, the coil wire would have been harder to reach!
EDITED-I just watched your good video and your shifter handle cable is good.
 
Last edited:

cturboaddict

Founding Member
As far as the little ball on top of the shifter goes, if you can move it with your thumb and the little gate? moves up and down in the notches then that cable is in good shape.(Edited-I see now after re-reading that you said it was good). The black push button in the left side of the T-handle can easily be installed the wrong way. It will only work one way. As far as the "kickdown" cable goes, there are two ways that the arm that it is hooked to the throttle pedal assembly. Some were welded, some had a very small U-bolt attaching the arm to the throttle rod. A welded one could be bent out of adjustment and the U-bolt type could be loose or tightened down in the wrong position. Maybe a user here has the info on adjusting that, that they could share. If I was standing over it I could adjust it. However the basics of it are, it shouldn't have any tension on it until you press the pedal to the floor.
I remembered a 3rd situation where one dropped in reverse on me. It was V-8 powered and The coil wire was in reach to yank and shut down the engine. If it had been straight six, the coil wire would have been harder to reach!
EDITED-I just watched your good video and your shifter handle cable is good.
I ordered all new kickdown parts as the old ones were a little shotty (as you can see in the video/photos), and they were missing some holding clips.
Anyhow, I read......
You disconnect the kickdown from the throttle linkage side. (NOT the trans side)
Confirm the gas pedal is at the correct height off the floor. (I think it's 4 1/4 or 4 1/2 inches)
Have someone press the pedal to the floor and hold it there (or slightly off of the floor, maybe 3/16").
Adjust the kickdown linkage to line up with the holes while the pedal is pressed to the floor.
And hook it back up.

Drive it and confirm the shifting- adjust as necessary.

Here is a good write up on the kickdown install. I had another about tips for adjusting, but I'll have to dig for it.
 
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