Shift cable O Ring

[Stumper]

Haven’t turned up anything in the search so thought I’d start a thread. Anyone know what size the O Ring is that seals the shift cable shaft on an early button shift 727? I have an assortment and a 11/16 OD - 1/2 ID looks about right but I only have rings that are 3/32” thick and the groove on the shaft looks to take more like a 1/8” thick ring.

 

[moes]

.437" OD X .070" thick. If my memory is correct

 

[wagonman]

I got one gifted from a member here along with the gasket, cant remember who. I will see if I can find out with some research. It sealed it for a while but is leaking again. Dont know if the housing is worn or I am getting a drain back from the convertor or what?

 

[wagonman]

Found it 493 Mike

 

[moes]

I've had friends with the same problem with leaking. I think they used heat shrink tube with glue to seal the cable and housing to stop the leakage.

 

[Stumper]

Wouldn’t be .437” OD. That might be the ID? The groove in the shaft measures right at .5” and the opening is .635”

 

[khryslerkid]

https://www.forbbodiesonly.com/mopa...tton-727-transmission-o-ring-seal-kit.234184/

 

[Ron H]

Epoxied my old cable that lasted me a couple years until came time to have to adjust the wheel. That futzing put enough stress on the cable to start it leaking again on my '63. With engine rebuild/headers forked out for a new one and added heat-resistant wrapping for extra measure nearer the headers. In my encounters, the cable doesn't offer a whole lot of slack as it's important to get the wheel dead 'flat' against the trans housing for the adjusting adding the ever-present trans oil on hands. Now I get two helpers, lol. One on the button, other down below with me to hold the cable forward while I adjust the wheel and get the nut on. I stripped the bore once, careful as I thought I was; but the condition of the threads were questionable to begin with despite having cleaned the hole and ran a tap in it. Aluminum!

 

[Stumper]

Found it 493 Mike

What’s 493? Is that the ID of the O ring? That would be about right to fit on the groove of the shaft. The OD of the o ring has to be something close to 0.65” to seal the hole.

 

[Stumper]

I've had friends with the same problem with leaking. I think they used heat shrink tube with glue to seal the cable and housing to stop the leakage.

That’s what started all this. It was leaking out the cable so I took it apart to get some shrink tube on it. It was not leaking around the case opening but when I got it apart I found that someone had gobbed a bunch of RTV all around the threaded part of the shaft that went into the hole. It was also all around the ORing that was on the cable shaft. Obviously the original design had it sealed in the case hole just with the ORing. But it needs to be the right ORing..

 

[wagonman]

What’s 493? Is that the ID of the O ring? That would be about right to fit on the groove of the shaft. The OD of the o ring has to be something close to 0.65” to seal the hole.

That is the Member name that gifted me the parts

 

[moes]

Sorry Stumper, I gave you the Park cable o ring size.

Park cable '62-'65 .437" X .070"

The correct size is

Shift cable '60-'65 .700 X .100"

It took me sometime to find where I had this information stored.

 

[Stumper]

Sorry Stumper, I gave you the Park cable o ring size.

Park cable '62-'65 .437" X .070"

The correct size is

Shift cable '60-'65 .700 X .100"

It took me sometime to find where I had this information stored.

Thanks Moes, I picked one up today at Napa that was listed as a 11/16 x 3/32 but it was a tad bigger and thicker than the same sized ones in my box so should be closer to the .7 x .1. I’ll button it up tomorrow and see if it leaks…..

 

[Stumper]

everything that didn’t leak before leaks now - but the cable is dry - so far…
Put fluid in and almost immediately started leaking at the front corners of the pan… now I know why those corners were beat up.. I had tried to straighten them up - yea well that didn’t work. Also have some leaking around that damn O ring now that wasn’t there before.
I used a Mopar performance rubber pan gasket - without any sealer. I have never, ever had any luck with rubber or silicone gaskets. Should have just used a cork gasket and light sealer…

 

[Ron H]

I used a cork gasket on my pan using permatex that also helps keep the gasket from shifting dealing with all the bolts and torquing sequence. If the pan is beat up though that's another obvious killer with obtaining a seal..

 

[Stumper]

Almost seems like it’s just not tightening up enough. Are those bolt holes pretty shallow? I’m wondering if the bolts are bottoming out. Guess I could try adding some washers to see if it draws up tighter.

 

[Ron H]

Almost seems like it’s just not tightening up enough. Are those bolt holes pretty shallow? I’m wondering if the bolts are bottoming out. Guess I could try adding some washers to see if it draws up tighter.

Make sure the holes are clean and cleaned out. Check the hole and bolt threads for condition carefully running a tap or good bolt into them. Use the bolts, if in good condition, into the holes to make sure they all seat fully. If any binding, don’t force them in. I use anti-seize in bolt and screw holes as a regimen. With most bolts, like head, manifold, water pump bolts, etc. I don’t use the old bolts, don’t like taking the chance one could strip or break. Could be, if the pan as you mention isn'tin good shape, someone may have over-torqued some.

 

[Stumper]

Something else I ran into with this little project that I would appreciate any thoughts / experience on. My shift cable runs behind the exhaust down pipe as seen in this picture.

There is quite a bit of upward tension on the shift cable where it goes into the case. I was hoping I had enough slack in the cable to reroute it to the front of the exhaust pipe so there was less upward tension on the cable but there wasn’t any slack. Can anyone with a stock exhaust tell me if their cable runs in front of or behind the down pipe?
There is quite a bit of upward tension on the cable connector with my setup and while the shrink tube seems to have stopped the cable leak for now there is still seepage around the ORing coming through.

I didn’t realize it before but it is pretty easy to wiggle the cable threaded shaft in the adjuster wheel. Seems like it could use a thin nut on the outside to help keep it centered in the case hole?

 

[Ron H]

Try removing the wire tie and gently tug on the cable watching how it is routed up though the firewall for any chance to find any slack. Also check under the dash. Don't like the wire tie being so near to the adjuster or if you replace the tie, move it further away. You should have at least an inch or so of clearance away from the exhaust to prevent it from getting too hot. As a precaution I used a heat-resistant jacket in the area of the exhaust. Could also use a wrap.

 

[Stumper]

I’ve checked for slack , there is none. Was wondering if the cable might not be correct for the car- too short? That’s why I was curious where others have their cable with a stock exhaust. Right now the cable is a good 1- 11/2 away from the pipe so not concerned about the heat (though a heat shield would be a good idea) but I don’t like the upward tension it puts on that cable.