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Discussion Starter #1
Transmission is leaking at speedometer cable. first issue was the TV cable was not installed and transmission did not leak. brought it to the shop that rebuilt the transmission and who forgot to install the TV linkage. They dropped the pan. installed linkage for TV cable and new cable. the pan was put back on. I then drove home. parked car in the garage. A few days later i noticed it was leaking. found its leaking at speedo cable. changed gear and housing. still leaking. this is on a 1969 pontiac firebird 350

because i had no leaking issues prior to the pan being removed. It must be related to the last work that was done.

Any advise would be great.
 

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Transmission is leaking at speedometer cable. first issue was the TV cable was not installed and transmission did not leak. brought it to the shop that rebuilt the transmission and who forgot to install the TV linkage. They dropped the pan. installed linkage for TV cable and new cable. the pan was put back on. I then drove home. parked car in the garage. A few days later i noticed it was leaking. found its leaking at speedo cable. changed gear and housing. still leaking. this is on a 1969 pontiac firebird 350

because i had no leaking issues prior to the pan being removed. It must be related to the last work that was done.

Any advise would be great.
If it's really leaking at the speedo cable, that's unrelated to the pan being dropped. There are two O-rings that seal at the speedo cable. One is on the outside of the speedo cable adapter that seals the adapter to the case. The other is on the INSIDE of the adapter and seals the adapter to the speedo driven gear. Most people overlook the latter and the leak isn't fixed.

Also, unless your trans has been replaced with a later model OD trans, it doesn't have a TV cable. It's a TH350 and that's a kickdown cable. It looks like a TV cable, but the function is different.
 

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If you changed the housing did you push the inside o-ring down inside? Some housings don't come with it pushed in, just at the outer lip.
 

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If you need a new adapter entirely; it is GM P/N 345215 and comes with the inner seal, check to make sure its seated correctly. Sometimes the outer o-ring is included; sometimes not. It is a standard SAE "115." Your hardware store should have one. As stated above; make sure you lube it lightly and when you install it, make sure it doesn't tear.
 

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Discussion Starter #6
I still have the original transmission case. I did change out the speedometer gear and housing with another one from a 1969 firebird. It just seems strange that I went several months with no leaks. then the kickdown cable was installed. the pan was removed and installed again. took the car home and put it away. then notice later it was leaking.
I have read about breather being blocked or if gasket was installed incorrectly. As I have no experience that is why I made this post.
I will look online for the parts mentioned. I have to purchase everything online as I am an american with a 1969 firebird convertible who lives in the middle east. I've had the car for 24 years. brought it here 5 years ago. I work a a US military base. no professional hardware stores. just local ones that don't carry US sizes and parts.
 
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