C6 transmission linkage questions

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

jmassey6

Member
Joined
Oct 15, 2017
Messages
12
Reaction score
0
Location
Santa Clarita, CA
My Car
1973 Ford Mustang Mach I Fastback, 351C-2V, AT, PS, AC, dual exhaust
Hello all:

Great forum.  This is my first post so hopefully, it is correct!  :cool:  I have a 1973 Ford Mustang Mach 1 Fastback with a 351C-2V and C6 transmission which I am rebuilding to as close as original as possible.  Unfortunately, the prior owner(s) removed many components from the car.  I am specifically having an issue determining how to connect the C6 linkage to the transmission (i.e. the lockout rod, shifter rod and kickdown rod).  And the Ford manuals do not appear to help me see how they are all connected - neither do photos from Google.  Below are some photos - first of the parts I have available (again which are not shown in the 1973 Ford manual it would appear) and the two (2) others are of the existing transmission, rods and apparent connection point.  Now the questions:

1.  Does anyone have a diagram showing the assembly of the linkage for the 1973 Mustang C6 transmission they could share?

2.  Am I missing parts to complete the assembly (it would appear so)?

3.  Does anyone have any clear photos of the C6 linkage that I could review/compare to?

Thanks in advance for the help!

-Jeff M







 
I did not see a neutral safety switch in your pictures. The lever shaft and two bolts in the first pic below is where you attach the switch. There is a section in the shop manuals that explain how to install it and adjust the shift linkage. I am away now and can post it later in the week if you still need it.







 
Last edited by a moderator:
Looks like the stock arms on the shifter quadrant were cut off. A possible reason is that the trans you have is from a column shift car.

This is what you need, plus the neutral safety switch. Trans pan and valve body need to come out to swap the shift arm.

http://www.missourimustang.com/1970-73-shifter-lever-arm-shaft-c6-428cj/
Thanks for the reply.  My transmission has the neutral safety switch inside of the shifter assembly inside the car and not on the transmission.  The one you show is silver/grey in metal color while the one inside the shifter assembly is blue plastic (see attached photo).  When the transmission was removed, I do not recall a neutral safety switch on the side above the linkage and the car ran prior to removing it and having it rebuilt.  I suppose it is possible that someone put a different C6 transmission or shifter in during some type of rebuild since the car was rough when I purchased it however, I know I drove it off the trailer so it worked.   I am a bit bewildered since I cannot make heads or tails of the parts I have on my car.  The transmission is a C6 however, according to CJ Pony Parts, the neutral safety switch I have is for an FMX transmission:

https://www.cjponyparts.com/neutral-safety-switch-assembly-fmx-1969-1973/p/HW2951/

Product Description

Neutral Safety Switch Assembly for 1969-1973 Mustangs with a FMX Automatic Transmission.

This is an exact reproduction of the original part, made using the original blue prints and NOS samples. Each switch is individually tested by the manufacture to ensure proper function.

 


Please Note: Ford replaced the 1969-1970 version with the 1971-1973 version which has an extra wire for accessory options. 1969-1970 cars will not need the extra wire, it can be cut off or left alone.





The photo below is of the shifter before I rebuilt it like for like with the same parts. 



The other issue is that if you look at the photo of the existing parts I have, it has a part which I circled which I cannot identify in my various Ford manuals from 1973. 

 




 


Any additional assistance/insight would be greatly appreciated. :huh:   Thanks again.


-Jeff

 
I did not see a neutral safety switch in your pictures. The lever shaft and two bolts in the first pic below is where you attach the switch. There is a section in the shop manuals that explain how to install it and adjust the shift linkage. I am away now and can post it later in the week if you still need it.





Sorry...I replied to Hemikiller and you only in one post to him.  Please see my comments about the neutral safety switch.  Thanks.

-Jeff

 
All:

I have attached some photos of the transmission before I reinstalled it in the car which I am pretty sure is a C6 (but now I am questioning) in addition to a diagram for some of the linkage I found for the Mustang...I am not sure if this helps but I am just trying to paint a picture...thanks in advance.









 
The standard issue transmission for the 71-73 351-2V cars was an FMX, which is why you have the FMX neutral safety switch in your shifter. Take a look at your door data plate, it probably has an "X" in the trans data spot. The C-6 was reserved for the 4V cars. Looking at what you have, my guess is that transmission came from a column shift car. There is usually a tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx". If you have it and post it here, I can decode the tag for you.

Regardless, you have it in and need to get it to work. The circled part is some sort of aftermarket shifter arm. Probably originally intended for a ratchet shifter from Hurst, B&M, etc. At this point, I would use it to get you mobile. The column back drive rod can be left off. The kickdown should work, as long as you have a C-6 kickdown for a 2V carb. To set up the shifter, manually rotate the shifter shaft to park, which you can check by rotating the driveshaft until it locks in. Once there, go two "clicks" back to get you to neutral. Set the shift selector to neutral and install your linkage. Follow the factory procedure to adjust the neutral safety switch and you should be good to go.

Going forward, you should think about getting the correct shifter shaft that I linked you to. Nothing works 100% unless you have the correct parts. I have a friend with the same setup as you and the same butchered column shift transmission. His car sometimes just won't lock into park. Keep in mind that the transmission was like a package deal with Ford. The transmission, flexplate, crossmember, shift rod, backdrive rod, kickdown and other bits were all specific to the C-6. You need everything, save maybe the kickdown, to make it all work properly. You can modify the kickdown to make it work.

 
The standard issue transmission for the 71-73 351-2V cars was an FMX, which is why you have the FMX neutral safety switch in your shifter. Take a look at your door data plate, it probably has an "X" in the trans data spot. The C-6 was reserved for the 4V cars. Looking at what you have, my guess is that transmission came from a column shift car. There is usually a tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx". If you have it and post it here, I can decode the tag for you.

Regardless, you have it in and need to get it to work. The circled part is some sort of aftermarket shifter arm. Probably originally intended for a ratchet shifter from Hurst, B&M, etc. At this point, I would use it to get you mobile. The column back drive rod can be left off. The kickdown should work, as long as you have a C-6 kickdown for a 2V carb. To set up the shifter, manually rotate the shifter shaft to park, which you can check by rotating the driveshaft until it locks in. Once there, go two "clicks" back to get you to neutral. Set the shift selector to neutral and install your linkage. Follow the factory procedure to adjust the neutral safety switch and you should be good to go.

Going forward, you should think about getting the correct shifter shaft that I linked you to. Nothing works 100% unless you have the correct parts. I have a friend with the same setup as you and the same butchered column shift transmission. His car sometimes just won't lock into park. Keep in mind that the transmission was like a package deal with Ford. The transmission, flexplate, crossmember, shift rod, backdrive rod, kickdown and other bits were all specific to the C-6. You need everything, save maybe the kickdown, to make it all work properly. You can modify the kickdown to make it work.
Great insight Hemikiller...my transmission Code is actually "U" which I decoded as the C-6 transmission (please see the attached photos below).  Does that change your thought process or do I still need the shaft you mentioned?  If so, that is fine however, I will just need to figure out how to install it.  Would you surmise that I need any other parts to get the three (3) rods and linkages working together other than the one you listed?  As to the servo code, I will look on the transmission when I return from a business trip on Thursday, snap a photo and post it. 



picture upload





Thanks again for your help.

 
The standard issue transmission for the 71-73 351-2V cars was an FMX, which is why you have the FMX neutral safety switch in your shifter. Take a look at your door data plate, it probably has an "X" in the trans data spot. The C-6 was reserved for the 4V cars. Looking at what you have, my guess is that transmission came from a column shift car. There is usually a tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx". If you have it and post it here, I can decode the tag for you.

Regardless, you have it in and need to get it to work. The circled part is some sort of aftermarket shifter arm. Probably originally intended for a ratchet shifter from Hurst, B&M, etc. At this point, I would use it to get you mobile. The column back drive rod can be left off. The kickdown should work, as long as you have a C-6 kickdown for a 2V carb. To set up the shifter, manually rotate the shifter shaft to park, which you can check by rotating the driveshaft until it locks in. Once there, go two "clicks" back to get you to neutral. Set the shift selector to neutral and install your linkage. Follow the factory procedure to adjust the neutral safety switch and you should be good to go.

Going forward, you should think about getting the correct shifter shaft that I linked you to. Nothing works 100% unless you have the correct parts. I have a friend with the same setup as you and the same butchered column shift transmission. His car sometimes just won't lock into park. Keep in mind that the transmission was like a package deal with Ford. The transmission, flexplate, crossmember, shift rod, backdrive rod, kickdown and other bits were all specific to the C-6. You need everything, save maybe the kickdown, to make it all work properly. You can modify the kickdown to make it work.
Hi Hemikiller...I think you are correct for the shaft at Missouri Mustang however, I also think there is not a location on my transmission for a neutral safety switch around the linkage shaft as others have shown in their photos.  It is in my shifter assembly. Please look at the two (2) attached photos and let me know what you think about the linkage connections and if the recommended shaft is what is pictured.  I think this is the set up I need.  Your thoughts are most welcome...thanks!

-Jeff







 
The October Mustang Monthly article that you posted the pictures from detailed a '71 C6 Automatic Transmission" for the "385 Engines"... 429 CJ/SCJ C6. The bell housing on these is different than a small block (Windsor/351C) bell housing. In addition, it does not appear to have both bolt holes for the Saftey switch, not sure why, but your does...

Also, have you checked your trani's serial number to see if it matches your car's serial number? Looks like there is possibly a 2013 serviced date marked on it. If the serial number matches your car maybe it was rebuilt at some point? If the numbers don't match then the original was replaced.



As Hemikiller said, locate the the tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx" Example...







 
Last edited by a moderator:
I think your transmission had the arms butchered off for an aftermarket shifter and then had an FMX shifter assembly substituted when the PO tried to bring it back to stock. And yes, as rackerm noted, I can now see the mounting points for the NSS, so disregard my observations in the PM I sent earlier regarding it. You can use it and it'll work fine, as long as you have the correct shift rods to match your C-6.



 
The standard issue transmission for the 71-73 351-2V cars was an FMX, which is why you have the FMX neutral safety switch in your shifter. Take a look at your door data plate, it probably has an "X" in the trans data spot. The C-6 was reserved for the 4V cars. Looking at what you have, my guess is that transmission came from a column shift car. There is usually a tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx". If you have it and post it here, I can decode the tag for you.

Regardless, you have it in and need to get it to work. The circled part is some sort of aftermarket shifter arm. Probably originally intended for a ratchet shifter from Hurst, B&M, etc. At this point, I would use it to get you mobile. The column back drive rod can be left off. The kickdown should work, as long as you have a C-6 kickdown for a 2V carb. To set up the shifter, manually rotate the shifter shaft to park, which you can check by rotating the driveshaft until it locks in. Once there, go two "clicks" back to get you to neutral. Set the shift selector to neutral and install your linkage. Follow the factory procedure to adjust the neutral safety switch and you should be good to go.

Going forward, you should think about getting the correct shifter shaft that I linked you to. Nothing works 100% unless you have the correct parts. I have a friend with the same setup as you and the same butchered column shift transmission. His car sometimes just won't lock into park. Keep in mind that the transmission was like a package deal with Ford. The transmission, flexplate, crossmember, shift rod, backdrive rod, kickdown and other bits were all specific to the C-6. You need everything, save maybe the kickdown, to make it all work properly. You can modify the kickdown to make it work.
Hi Hemikiller...I think you are correct for the shaft at Missouri Mustang however, I also think there is not a location on my transmission for a neutral safety switch around the linkage shaft as others have shown in their photos.  It is in my shifter assembly. Please look at the two (2) attached photos and let me know what you think about the linkage connections and if the recommended shaft is what is pictured.  I think this is the set up I need.  Your thoughts are most welcome...thanks!

-Jeff





After you install the correct Shifter Lever Arm & Shaft and Neutral Saftey Switch with the Shift Lever and Lockout arms reconnected, the attached from the 1973 Ford Shop Manual Volume 1 - Part 17-02 Shift Control Linkage will help to step you thru making the needed linkage and safety switch adjustments.

Shop Manual Volume 1 - Part 17-02 Shift Control Linkage.pdf

 

Attachments

  • Shop Manual Volume 1 - Part 17-02 Shift Control Linkage.pdf
    3 MB · Views: 31
The October Mustang Monthly article that you posted the pictures from detailed a '71 C6 Automatic Transmission" for the "385 Engines"... 429 CJ/SCJ C6. The bell housing on these is different than a small block (Windsor/351C) bell housing. In addition, it does not appear to have both bolt holes for the Saftey switch, not sure why, but your does...

Also, have you checked your trani's serial number to see if it matches your car's serial number? Looks like there is possibly a 2013 serviced date marked on it. If the serial number matches your car maybe it was rebuilt at some point? If the numbers don't match then the original was replaced.



As Hemikiller said, locate the the tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx" Example...





Thanks for the replies.  It appears that I am missing another part based on the photo I have re-attached and made notes on it.  Do you know the part number for this item?  I have both arms/attachments now including the one (1) Hemikiller suggested to buy but not the part in between them on the attached photos?  Also, to install the arm that Hemikiller





 


recommended to purchase from Missouri Mustang (which I did), do you have any recommended steps to do so?  I surmise I will need some type of seal and a list of of steps to install it, correct?  Or would you recommend that I have a transmission shop do it?


Thanks in advance.

-Jeff

 
I don't see that part in the MPC, or I'm just looking in the wrong place.

You have to drop the pan and valve body. If you're comfortable with that, it's not a hard job.

 
The October Mustang Monthly article that you posted the pictures from detailed a '71 C6 Automatic Transmission" for the "385 Engines"... 429 CJ/SCJ C6. The bell housing on these is different than a small block (Windsor/351C) bell housing. In addition, it does not appear to have both bolt holes for the Saftey switch, not sure why, but your does...

Also, have you checked your trani's serial number to see if it matches your car's serial number? Looks like there is possibly a 2013 serviced date marked on it. If the serial number matches your car maybe it was rebuilt at some point? If the numbers don't match then the original was replaced.



As Hemikiller said, locate the the tag attached to the servo cover bolts. That should have a set of codes on it normally like "Pxx-xx" Example...


Thanks for the replies. It appears that I am missing another part based on the photo I have re-attached and made notes on it. Do you know the part number for this item? I have both arms/attachments now including the one (1) Hemikiller suggested to buy but not the part in between them on the attached photos? Also, to install the arm that Hemikiller








recommended to purchase from Missouri Mustang (which I did), do you have any recommended steps to do so? I surmise I will need some type of seal and a list of of steps to install it, correct? Or would you recommend that I have a transmission shop do it?

Thanks in advance.

-Jeff


That lever you circled in the picture is not used in the C6 for our cars. If you look closely at the picture you posted, the mounting holes do not match your trans. The trans in the picture does not appear to have provisions for a neutral safety switch, since the trans in the picture has only one mounting hole at 11 o'clock, whereas your (and my) trans have two holes 1) 11 o'clock and 2) 5 o'clock. These two holes are used to mount the neutral safety switch. You need the shift lever identified by Hemikiller earlier post, the kick down lever (on the left at 9 o'clock in your picture) and the correct neutral safety switch. Your trans should look like the picture below before you install the Neutral Saftey Switch (note the two Neutral Saftey Switch mounting holes/bolts). It might be best to it take it to a Transmission guy to have it installed as described in this thread. Once the trans is installed and all linkage and wiring are connected, use the PDF I attached earlier to correctly adjust the neutral safety switch so your ignition key switch lockout, backup lights, and seat belt warning buzzer all operate correctly based on the position of the shift lever (e.g. P R N D 2 1).

 
Back
Top