Transmission linkage

[checkoutmyjunk]

Hey all,


Looking for some help again—this time with transmission linkage.


I have a 1968 Polara 500, 383 with a 2-barrel, mated to a 727. The car is an unfinished project from a close friend who passed, so unfortunately I can’t ask him the important questions—like what happened to the original linkage?!


The story goes that he swapped in another lower-mileage 383, but I have no idea what year or model it came from. Here’s the issue:

• The kickdown rod end diameter is .310",
• But the linkage on the transmission seems to want .250".

My first thought was to just mill the rod end down to .250" and hope I can adjust everything to factory specs afterward. But before I start modifying parts, I wanted to check if I’m missing something simple.


My assumption is that, even though both engines were 383s with 2-barrels, the donor engine may have been from a different year or model—possibly with a slightly different transmission setup, which could explain the mismatch in kickdown linkage diameters.


Does this make sense to anyone familiar with these linkages? Would Dodge really change the diameter of the linkage boss like this between years or models?


As always, I appreciate any help or insight you’re kind enough to share.

 

[57fury440]

Does the piece on the transmission have a rubber grommet in it?

 

[CBODY67]

Rather than mill the rod end, why not enlarge the hole it needs to fit into? Or possibly decrease teh rod diameter a bit and enlarge the hole a bit, such that EACH one is changed enough to interface as desired?

The material in the rod is not a really tough steel, by observation. A common file can shorten it, for example, from my experiences.

CBPDY67

 

[checkoutmyjunk]

Does the piece on the transmission have a rubber grommet in it?

Not that I can see. Here's a pic.

 

[checkoutmyjunk]

Rather than mill the rod end, why not enlarge the hole it needs to fit into? Or possibly decrease teh rod diameter a bit and enlarge the hole a bit, such that EACH one is changed enough to interface as desired?

The material in the rod is not a really tough steel, by observation. A common file can shorten it, for example, from my experiences.

CBPDY67

I handed this off to our best manual machineist and he gave it back telling me it's been hardened at the tip and his files were bouncing off it. Next I asked the wire edm lead and he checked the Rockwell and she was pretty hard. The CNC mill guy told me he could put it in a vice and could write a little program to remove enough material to take it down to .250". But like I said, idike to know what I have and possibly just buy what I need before I start to modify it.

 

[checkoutmyjunk]

Welp, after a archeological dig in the trunk, I found two linkages. The boss is the right diameter on the trunk found unit, but it looks like it was mangled up when the engine was swapped. Now I guess I need to bend it back into shape. Hopefully the manual will give me a idea what she was supposed to look like.

 

[CBODY67]

Yes, the FSM has a very good illustration of the linkages. Might be a bit generic, but still good. www.mymopar.com . Might need to manually input that address.

CBODY67

 

[65CopCar]

I don't know if 67 is the same, but somewhere I have 67 polara 383 set. I can see if I can find it and measure it. If its .25 you can have it for shipping cost.

 

[65CopCar]

Parts book confirms 67 and 68 are the same.

 

[checkoutmyjunk]

Parts book confirms 67 and 68 are the same.

Thanks, I appreciate it.
The part is mostly back in shape now. The threads are a bit off—kind of like an overextended Slinky—but manageable.


The next thing I need to figure out is the clip. I could probably rig something up, but the issue is that the .310" clip is too big for the .250" rod...

 

[checkoutmyjunk]

Yes, the FSM has a very good illustration of the linkages. Might be a bit generic, but still good. www.mymopar.com . Might need to manually input that address.

CBODY67

Thanks again, I took a look and it looks like they used the same basic image for several bodies, not just the Cs that we have. Like I said, I think it's good enough for me and the girls I date!

 

[65CopCar]

Thanks, I appreciate it.
The part is mostly back in shape now. The threads are a bit off—kind of like an overextended Slinky—but manageable.


The next thing I need to figure out is the clip. I could probably rig something up, but the issue is that the .310" clip is too big for the .250" rod...

I found several linkages that are probably correct for you but the clips are missing. Only found the larger clips. More than likely they are in the clip box in the shop. Wont be in the shop for a day or two but will be happy to look.