A727 Trans Park Brake Cable

[GSPointer]

This winter I bought a 40k mile then 40 year forgotten 64 Imperial. It took a lot of work to get it running and driving and stopping. Many leaks were fixed along the way but many remain. The biggest being a trans fluid leak due to a dried out and crumbly park brake cover gasket.

When I removed the cover, I didn't disconnect the cable from the pawl properly and I mangled a fine wire at the cable's end which I believe attached the cable to the pawl? Does anyone have a drawing or some words of wisdom explaining how to reattach this without further disassembly?

I have not removed the cable from the cover, the o-ring seems to be sealing, so if I can't fix this without further disassembly and a big adjusting project, can I drive it with the cable unconnected? i.e. Without the brake cable attached, is the trans brake engaged or disengaged?

 

[CBODY67]

When I saw the title of the thread, I perceived "Trans Brake" to be a modification to an automatic transmission to apply a forward gear and reverse gear at the same time on the starting line of a drag strip. Hence, the rear suspension was sitting at "no preload" for the start, as the engien rpm was raised in prep for the green light to go on. This shocks the rear suspension and usually results a greater sudden force to better "plant" the rear tires for an explosive stating line start . . . providing nothing breaks.

What you have on the Imperial is a transmission mounted PARKING brake. At the time, Chrysler perceived that mechanism as being a better way to do things. Later, they followed everybody else with rear brake-located parking brakes.

Enjoy!
CBODY67

 

[GSPointer]

Yes, I don't plan to do any sub-10's except on the MPG.

 

[Big_John]

What you have on the Imperial is a transmission mounted PARKING brake. At the time, Chrysler perceived that mechanism as being a better way to do things. Later, they followed everybody else with rear brake-located parking brakes.

Gotta disagree with that.

That cable is for the park pawl, internal to the transmission.

What you are thinking of is the earlier cars that had the parking (or emergency) brake mounted on the rear of the tail shaft housing. I think the last year for that was 1962(?).

 

[Just Carbs]

Yes, I don't plan to do any sub-10's except on the MPG.

Thank you for bringing the possibility for that to happen to our attention.

 

[GSPointer]

Thank you for bringing the possibility for that to happen to our attention

This winter I bought a 40k mile then 40 year forgotten 64 Imperial. It took a lot of work to get it running and driving and stopping. Many leaks were fixed along the way but many remain. The biggest being a trans fluid leak due to a dried out and crumbly park brake cover gasket.

When I removed the cover, I didn't disconnect the cable from the pawl properly and I mangled a fine wire at the cable's end which I believe attached the cable to the pawl? Does anyone have a drawing or some words of wisdom explaining how to reattach this without further disassembly?

I have not removed the cable from the cover, the o-ring seems to be sealing, so if I can't fix this without further disassembly and a big adjusting project, can I drive it with the cable unconnected? i.e. Without the brake cable attached, is the trans brake engaged or disengaged?

View attachment 654107

This winter I bought a 40k mile then 40 year forgotten 64 Imperial. It took a lot of work to get it running and driving and stopping. Many leaks were fixed along the way but many remain. The biggest being a trans fluid leak due to a dried out and crumbly park brake cover gasket.

When I removed the cover, I didn't disconnect the cable from the pawl properly and I mangled a fine wire at the cable's end which I believe attached the cable to the pawl? Does anyone have a drawing or some words of wisdom explaining how to reattach this without further disassembly?

I have not removed the cable from the cover, the o-ring seems to be sealing, so if I can't fix this without further disassembly and a big adjusting project, can I drive it with the cable unconnected? i.e. Without the brake cable attached, is the trans brake engaged or disengaged?

View attachment 654107

 

[GSPointer]

My original description may have confused some. What I don't understand is how the A727's Parking lock cable engages the transmission's Parking Pawl?

From what I gather, the park pawl's default position is disengaged, so without a cable, the transmission is not in Park. When the park lever is thrown, the end of the cable pushes the pawl to engage a gear tooth and keep the vehicle parked.

I suspect this thin gage wire integral to the cables end is a locking feature whose primary purpose comes into play only if the transmission is slammed to park while the vehicle is still moving. When this happens, the parking pawl will ratchet with the gear it's trying to engage and this locking feature ensures proper orientation between the cable and pawl is maintained?

I'll bend the end into something that may or may not work and try to do any park slams. However, if anyone has a picture showing a close up of the parking cables end, it would be a big help, I can't seem to find one via google.

 

[CBODY67]

Might check the FSM for the existence of a Parking Pawl at all. Reason I say that is that in some of the 1956-era dealer training YouTubes I as looking at earlier this week (actually, they found me rather than otherwise), one mentioned that the rear parking brake was a better way to do things as it could be engaged as an "emergency brake" with the car moving other than other brands' "Park" engaging a parking pawl.

Seems like there were actually TWO cables in some of the '60s pushbutton operations? One for "the gears" and the other one for "parking functions"? Two separate cables within the main cable assy?

Just some thoughts,
CBODY67

 

[Big_John]

Might check the FSM for the existence of a Parking Pawl at all. Reason I say that is that in some of the 1956-era dealer training YouTubes I as looking at earlier this week (actually, they found me rather than otherwise), one mentioned that the rear parking brake was a better way to do things as it could be engaged as an "emergency brake" with the car moving other than other brands' "Park" engaging a parking pawl.

Seems like there were actually TWO cables in some of the '60s pushbutton operations? One for "the gears" and the other one for "parking functions"? Two separate cables within the main cable assy?

Just some thoughts,
CBODY67

For the aluminum 727, introduced in 1962, there were two cables, one for shifting gears and one for the parking pawl in 1963-1965. That stopped in 1966 when the cables were eliminated.

The park pawl was introduced in 1963, the same year as going to the parking/emergency brake on the rear axle. The aluminum 727 started in 1962, but that had no parking pawl although it did have the trans mounted parking brake.

Bottom line is the OP's 1964 Imperial has a parking pawl that is controlled by one cable with shifting being controlled by another cable and it also has a rear axle mounted parking/emergency brake. The messed up cable is for the parking pawl and nothing else.

I have two 1965 cars, both cable shifted with 2 cables. I have had the valve body out of one, but haven't had to deal with the parking pawl cable, so I have no tips on removal/install/repair to give. Seems like someone here should have done this and can comment.

 

[GSPointer]

For the aluminum 727, introduced in 1962, there were two cables, one for shifting gears and one for the parking pawl in 1963-1965. That stopped in 1966 when the cables were eliminated.

The park pawl was introduced in 1963, the same year as going to the parking/emergency brake on the rear axle. The aluminum 727 started in 1962, but that had no parking pawl although it did have the trans mounted parking brake.

Bottom line is the OP's 1964 Imperial has a parking pawl that is controlled by one cable with shifting being controlled by another cable and it also has a rear axle mounted parking/emergency brake. The messed up cable is for the parking pawl and nothing else.

I have two 1965 cars, both cable shifted with 2 cables. I have had the valve body out of one, but haven't had to deal with the parking pawl cable, so I have no tips on removal/install/repair to give. Seems like someone here should have done this and can comment.

For the aluminum 727, introduced in 1962, there were two cables, one for shifting gears and one for the parking pawl in 1963-1965. That stopped in 1966 when the cables were eliminated.

The park pawl was introduced in 1963, the same year as going to the parking/emergency brake on the rear axle. The aluminum 727 started in 1962, but that had no parking pawl although it did have the trans mounted parking brake.

Bottom line is the OP's 1964 Imperial has a parking pawl that is controlled by one cable with shifting being controlled by another cable and it also has a rear axle mounted parking/emergency brake. The messed up cable is for the parking pawl and nothing else.

I have two 1965 cars, both cable shifted with 2 cables. I have had the valve body out of one, but haven't had to deal with the parking pawl cable, so I have no tips on removal/install/repair to give. Seems like someone here should have done this and can comment.

My clip fabrication-during-installation idea is impossible to execute!

However, if I understand you correctly, for 63 through 65 the trans park pawl was pretty much redundant to the foot actuated parking brake. I could eliminate the parking brake cable altogether and just leave the pawl dangling, because my foot actuated park brake applies the rear brakes via its own cable?

If true, I could seal up the pawl cover's cable hole (without a cable in the way) and (likely) never have a leak in this 10 square inch area ever again? My foot actuated park brake and cable does the job and never leaked a drop of anything!

Please tell me that seems to make sense, after the day it just gave me, I would absolutely love to rip that cable out by the roots!

 

[Big_John]

However, if I understand you correctly, for 63 through 65 the trans park pawl was pretty much redundant to the foot actuated parking brake. I could eliminate the parking brake cable altogether and just leave the pawl dangling, because my foot actuated park brake applies the rear brakes via its own cable?

I wouldn't say "redundant". The parking pawl locks the driveshaft which locks the wheels. The rear parking brake has it's limitations. It applies the brakes, but it really doesn't lock the wheels... especially in reverse. I've seen cars with just emergency brakes set roll away.... Even had my '63 Dodge get hit by one in a parking lot many years ago.

I think what you did was damage the cable... I'm not sure though...

I found this, see if it helps. Mopar Push-button transmission park cable tech tips

If you decide the cable is damaged, I've been told these guys do a great job with building you a new one, but you'll probably have to send them your old one. Control Cables | Industrial Motion Controls | Street Rod Parts & Accessories

In the past, Imperial Services was always recommended for cables, but they are slow and expensive so I recommend not buying from them.

As I said, I have two cable shifted cars, but I've never had the parking cable apart in either.

 

[GSPointer]

I wouldn't say "redundant". The parking pawl locks the driveshaft which locks the wheels. The rear parking brake has it's limitations. It applies the brakes, but it really doesn't lock the wheels... especially in reverse. I've seen cars with just emergency brakes set roll away.... Even had my '63 Dodge get hit by one in a parking lot many years ago.

I think what you did was damage the cable... I'm not sure though...

I found this, see if it helps. Mopar Push-button transmission park cable tech tips

If you decide the cable is damaged, I've been told these guys do a great job with building you a new one, but you'll probably have to send them your old one. Control Cables | Industrial Motion Controls | Street Rod Parts & Accessories

In the past, Imperial Services was always recommended for cables, but they are slow and expensive so I recommend not buying from them.

As I said, I have two cable shifted cars, but I've never had the parking cable apart in either.

The tech tips will be a great help. I think I can get it back together with the cable attached to the pawl but I won't be able to reform the integral lock feature or fabricate one during the install. The pawl will then work properly but if it disconnects while in use due to the missing 'lock', I'll have to figure out a feasible alternate lock when I pull the engine to refresh the seals et

I wouldn't say "redundant". The parking pawl locks the driveshaft which locks the wheels. The rear parking brake has it's limitations. It applies the brakes, but it really doesn't lock the wheels... especially in reverse. I've seen cars with just emergency brakes set roll away.... Even had my '63 Dodge get hit by one in a parking lot many years ago.

I think what you did was damage the cable... I'm not sure though...

I found this, see if it helps. Mopar Push-button transmission park cable tech tips

If you decide the cable is damaged, I've been told these guys do a great job with building you a new one, but you'll probably have to send them your old one. Control Cables | Industrial Motion Controls | Street Rod Parts & Accessories

In the past, Imperial Services was always recommended for cables, but they are slow and expensive so I recommend not buying from them.

As I said, I have two cable shifted cars, but I've never had the parking cable apart in either.

I had to snip off the integral lock feature, and connect the cable to the pawl. Seems like it should hold w/o a lock but if it won't I can address it properly next winter when I pull the eng/trans. I'll leave a reply in a month or so with what I learn.

I really appreciate you sharing what you knew and the tech tips were very helpful as well. Thank you.