Appears to be something internally in the trans (disconnecting shifter didn't help), what could this be and is it something a novice can repair? Have to keep the rear up on jackstands or it'll drive right away upon starting it.
welcome abaord VMF!
sounds like you have some other issues as well. car should start at all while its in gear
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1970 Mach 1 San Jose built Dec 23 1969. Marti says 1 of 7. Purchased in 1987. Original family owner of the powertrain 351C 2v FMX.
1993 GT 11,000 miles, Built 2-12-93 Auto, 3:27 Axle, cloth, sunroof. Untouched except for rubber and battery, Purchased new 8-3-93. still has the factory windshield fluid and new car smell.
Location: In the Shenandoah Valley of Virginia....
Posts: 2,921
sounds like your neutral safety switch has been bypassed. If you have an original shifter ,etc. the switch should be mounted inside your shifter base ---under your shifter bezel. And connected out at the firewall.
__________________ My '70 Pro-Street. Mildly built 302, Mallory 6AL ignition, Hurst w/4-speed, 74 Maverick rear w/3.40 gears. Tied frame with 6 point cage. Trunk mounted battery, Dynamax Exhaust. Building a 351W 40 over now...
It just happened while pulling it in one day, it is not related to the shifter or linkage, or external neutral safety switch wiring, but must be in the trans itself. ??
Okay, the transmission is in drive all the time regardless of which gear the selector is in correct? And if you move the transmission selector arm by hand down on the transmission does it make a difference at all? If none of this makes a difference, it's possible the linkage inside of the transmission has failed. You can pull the oil pan and visually inspect the linkage inside of the transmission at the valve body.
Here is a pic curtest of mustangmedic youtube video.
Here is a link to rebuilding your fmx by badshoeproductions. Take a look and you will see more of the linkage.
That would be pretty unusual. I would raise up the car, and place chocks under the back wheels. Disconnect the linkage, and try moving the selector on the trans manually.
Location: In the Shenandoah Valley of Virginia....
Posts: 2,921
Sounds like the little lever the bolted to the end of your selector lever up inside the trans broke ---might have to drop valve body---
__________________ My '70 Pro-Street. Mildly built 302, Mallory 6AL ignition, Hurst w/4-speed, 74 Maverick rear w/3.40 gears. Tied frame with 6 point cage. Trunk mounted battery, Dynamax Exhaust. Building a 351W 40 over now...
The car is up on 4 jack stands. We disconnected the shifter linkage and tried moving the shifter to P and N etc, does not stop the wheels from spinning. Reason we thought it was the neutral safety switch is because it starts. And we were told by the seller (it happened while we were buying it) that he thought it was the NSS inside the trans, a clip or something? But either way, linkage or NSS we should be able to see it with just dropping the pan? Any way to get a detailed schematic or something on this so we know what we're looking for? Thanks guys!
Darcie
Location: In the Shenandoah Valley of Virginia....
Posts: 2,921
If it's a FMX the NNS is not inside the trans. Drop the pan. Don't know right off if you can see the lever that's attached to the end of your selector arm or not with out dropping the valve body but should be easy to find out one you get in there. Look for broken parts etc. in your fluid, on top the valve body, etc. Good luck--
__________________ My '70 Pro-Street. Mildly built 302, Mallory 6AL ignition, Hurst w/4-speed, 74 Maverick rear w/3.40 gears. Tied frame with 6 point cage. Trunk mounted battery, Dynamax Exhaust. Building a 351W 40 over now...
I believe that the FMX used the NSS mounted on the shifter inside the vehicle - if the shifter is in park or neutral inside the vehicle then it should start. If it's in reverse or drive gears then it won't start - my guess is the shifter is in park inside the car so it starts but the trans is stuck in drive.
Since it sounds like you've verified that nothing is hanging up on the shifter itself I'd drop the trans pan and look at the shift lever inside the transmission, the linkage and the parking pawl engagement - my guess is that it's something simple - and you may even find the parts of the linkage in the pan once you drop it. best to get pics of it or an exploded diagram of the trans to know how it should go back together...
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1968 Mustang Convertible was I6/auto now built 306/C4/8", disc brakes
1966 Mustang Coupe - driver I6/C4
1990 Mustang NCAA/7-up Convertible
Location: In the Shenandoah Valley of Virginia....
Posts: 2,921
Your believing right--the 69 mustang FMX NNS switch is suppose to be ''mounted in the shifter base/housing''---under the shift bezel.
__________________ My '70 Pro-Street. Mildly built 302, Mallory 6AL ignition, Hurst w/4-speed, 74 Maverick rear w/3.40 gears. Tied frame with 6 point cage. Trunk mounted battery, Dynamax Exhaust. Building a 351W 40 over now...
I'm in Lake City. If you want me to come by sometime and look under the car with you email me at v159hill@rconnect.com I have a 69 Mustang with a FMX and just sold a 70 with a FMX.
OK found the problem, a small piece that holds the shifter rod broke inside trans. I will try to add a pic of it....got a friend over and we're not sure if this piece can be replaced without more than dropping the pan and valve body...? anyone know?
We have a spare FMX here, but it doesn't seem to want to lock in park, hope the piece is good in that one.
Last edited by nickinator; 11-12-2012 at 02:54 PM.
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'70 Mach~ why is FMX stuck in drive?
My '70 Pro-Street. Mildly built 302, Mallory 6AL ignition, Hurst w/4-speed, 74 Maverick rear w/3.40 gears. Tied frame with 6 point cage. Trunk mounted battery, Dynamax Exhaust. Building a 351W 40 over now...
e have a spare FMX here, but it doesn't seem to want to lock in park, hope the piece is good in that one.
