Transmission leak from speedometer cable

J

Jrappl

Junior Member
1959 Edsel Ranger, 292 V8, 2 speed aluminum case Mile-O-Matic - restored.

When the car sits for a while (couple months) I get a fairly heavy leak from the speedometer cable. When I reassembled the car I replaced the o-ring on the cable and it is dry at the case so I don't believe the o-ring is leaking, it's farther down the cable.

Is the speedometer cable housing suppose to seal internally? Would replacing the cable solve the problem?

Or is the problem that the transmission fluid is draining back into the pan (dip stick reads high after it sits for a few days) and it gets too high in the tail?

During restore I did pull the transmission a part to clean it, adjusted the bands put new front and rear seals in and replaced the servo seals and cover seals. I had it open and draining without the valve body in it for about a week in several different positions and I drained the torque convertor.

The manual says capacity is 10 qts. I put about 1 qt in the torque convertor, reinstalled and put in about 8 more (1 shy of capacity). It reads just a tad low on the stick when warm.
 
The hub of the speedo cable at the extension housing end has an o-ring seal, so that when you insert the cable & gear assembly into the hole in the extension housing, it is kinda tough to push that hub down into the seat of the hole. Its also kinda tough to pull it back out.
If the cable hub went in fairly easily, you may have the wrong 0-ring, but new ones are available from your favorite repro parts suppliers.
I had one once upon a time that was old and had shrunk enough that it left a few drips of fluid on the pavement overnight, but now enough to make a significant puddle. When I installed a new o-ring, the drip stopped.
Make sure your speedo cable housing is packed with powdered graphite lube too.
 
I was ciphering on this and forgot all about it ...

When the car sits for a while (couple months) I get a fairly heavy leak from the speedometer cable. When I reassembled the car I replaced the o-ring on the cable and it is dry at the case so I don't believe the o-ring is leaking, it's farther down the cable.
Click to expand...

OP ...

Are you describing the fluid backing into the cable housing and not an external leak?
 
Or is the problem that the transmission fluid is draining back into the pan (dip stick reads high after it sits for a few days) and it gets too high in the tail?

During restore I did pull the transmission a part to clean it, adjusted the bands put new front and rear seals in and replaced the servo seals and cover seals. I had it open and draining without the valve body in it for about a week in several different positions and I drained the torque convertor.
Click to expand...

To see if the convertor is leaking down, take a dipstick reading immediately after shutdown. Without re-starting the car , take the same reading (not running) several times over the next few days and see if the level continues to rise. If it does, the convertor is leaking back.

Also make sure the vent is clean and operating properly and the trans is not over-filled.
 
I think the fluid is leaking from inside the cable. It is not leaking at the case but the cable starts showing wetness a few inches from the trans case.

The fluid then drips on the trans rear crossmember and down from there.
 
The cable housing itself is leaking? Is it porous at that point? Any chance there is an o-seal leak and is walking on the outside of the cable housing?

If not, internal case pressure is causing it to flow into the cable housing.
 
The cable housing is similar to flexible metal conduit used in the electrical industry. There is a continuous flexible plastic or rubber tube inside the metal housing, so there should be no way for fluid to leak from inside to outside of the housing.
is the speedo cable a repro? Did you pull the cable core out of the housing and flood it with graphite lubricant, then re-install the cable core prior to installing the assembly???
 
This is the original 62 year old cable. I did not pull it apart but I did check that it turned without restriction. It does work and the speedometer moves smoothly without jerking and without any noise.

I checked again yesterday and it is dry at the transmission case. The cable has a 6-8" outer spring to prevent it from being bend too sharply at the case end. The fluid catches on the spring an inch or so from the trans case and then it's just wet with fluid until the cable turns up to go up the firewall.

I did purchase a new cable and will try it.
 
... so there should be no way for fluid to leak from inside to outside of the housing
Click to expand...

Unless, the housing and/or liner has been compromised. There should be no ATF that far up the housing pointing to another cause.
 
And that was the original question. In normal operation and after a shutdown should fluid be high enough to fill the speedometer cable housing?

Currently, when warm and idling the trans fluid reads just above the "L" mark on the dipstick. The "H" mark is about an inch higher and the stick says 3/4 qt to go from "L" to "H".

I shut it off and after waiting about an hour the fluid level was up to the second "I" in "Transmission" on the stick - about 2 1/2 inches above the "L". I will continue checking over the next couple of days to see how high it goes. My guess is it will go higher because if it sits for a week or more, the next start causes fluid to leak out the top of the dipstick tube!

The vent cap moves easily and it looks clean. I don't see an easy way to actually remove the cap without pulling the transmission because there is very little room to get at it. If somebody knows a way to remove it I'm interested.
 
I did read #5, that's why I am checking the levels.
What is the fix for a leaking converter? Converter replacement or is there a seal that can be replaced? I did replace the front main (pump?) seal that the converter shaft slides into and I don't have anything leaking there.
 
Just checking, were you able to install the new cable and housing?

If a convertor is leaking down, it will leak into the main case and most likely not produce an obvious exterior leak other than say the filler tube, vent assy, front and/or rear seals or in your case walking up the cable housing.

If the case is overfilled at start-up, the resulting pressure and excess fluid has no where to go in an open trans design.

You need (IMO) a period F/M/2 workshop manual to properly diagnose.
 
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