Leaking xmission oil out of the speedometer input

[AndyBill402]

Transmission oil is dripping out of the speedometer input (where the cable screws into my TH350). I lose about a quart every 2 weeks. How do I fix it?

[7tonemonte]

It looks like I developed a leak in the same spot,I didnt know if it was possibly the convertor draining back into the pan from sitting,and it being overfilled?

I noticed mine after sitting for a few weeks of no driving, curious to see what advice is here

[Sam (Bones)]

there's probably a O-ring or seal in there that has went bad, pull the speedo unit out and take it apart, there will bee an outer O-ring too

[footballubet]

If the center of housing where the cable goes in to it you can buy the housing.

[58impala]

Take cable off input [you said a naughty!]. Pull input [you said a naughty!]. out and take to transmission shop. Cost me $2.50 and took them 5 minutes.

[58impala]

Not [you said a naughty!]. assembly

[7tonemonte]

Thanks for that info....Pretty funny you cant abbreviate assembly I had to hit the Quote button to reply to understand what you were cursing about

Welcome to the site and club by the way!!!

[wallaby]

...Pretty funny you cant abbreviate assembly

Maybe it should be assy.?

 

That's pretty funny though: I was trying to read the post and was inserting my own imagined bad words and it wasn't working out too well...

[kc8oye]

the speedo sender isn't under fluid when the engine is not running.. allthough some fluid will pool in the tail shaft housing, more likely it's leaking much more when running. is it leaking from where the speedo cable attaches? or is it leaking where the unit the speedo cable attaches is in the trans case?

 

either way, as suggested, just remove it, and have a trans shop throw some new seals at it.

[Big Jim]

I had the same problem and found the aluminum speedo gear housing was bad. Replaced it with a new steel speedo gear housing I bought off of Ebay and has not leaked since. Be careful not to loose the gear into the transmission when you pull the housing.Check out this link

 

http://www.transmissioncenter.net/speedo...J2godaUAAGw#350

[overdrive]

Check the shaft of the driven gear for wear. It's the plastic part that the square end on the cable fits into. Mine was worn and the new o-ring wasn't enough to seal it. I bought a new gear. They're cheap. The Parts Place has them:

 

Automatic Transmission & Related Parts - SPEEDOMETER GEARS - AUTOMATIC

Product Name Price

 

AT6322Z

 

 

(1970 - 1981 Monte Carlo) LIGHT GREEN AUTOMATIC SPEEDOMETER GEAR (34 TOOTH)

 

 

$15.00

 

 

AT6323Z

 

 

(1970 - 1981 Monte Carlo) ORANGE AUTOMATIC SPEEDOMETER GEAR (35 TOOTH)

 

 

$15.00

 

 

AT6324Z

 

 

(1970 - 1981 Monte Carlo) WHITE AUTOMATIC SPEEDOMETER GEAR (36 TOOTH)

 

 

$15.00

 

 

AT6325Z

 

 

(1970 - 1981 Monte Carlo) RED AUTOMATIC SPEEDOMETER GEAR (37 TOOTH)

 

 

$15.00

 

 

AT6326Z

 

 

(1970 - 1981 Monte Carlo) BLUE AUTOMATIC SPEEDOMETER GEAR (38 TOOTH)

 

 

$15.00

 

 

AT6327Z

 

 

(1970 - 1981 Monte Carlo) BROWN AUTOMATIC SPEEDOMETER GEAR (39 TOOTH)

 

 

$15.00

 

 

AT6328Z

 

 

(1970 - 1981 Monte Carlo) BLACK AUTOMATIC SPEEDOMETER GEAR (40 TOOTH)

 

 

$15.00

 

 

AT6329Z

 

 

(1970 - 1981 Monte Carlo) YELLOW AUTOMATIC SPEEDOMETER GEAR (41 TOOTH)

 

 

$15.00

 

 

AT6330Z

 

 

(1970 - 1981 Monte Carlo) GREEN AUTOMATIC SPEEDOMETER GEAR (42 TOOTH)

 

 

$15.00

 

 

AT6331Z

 

 

(1970 - 1981 Monte Carlo) PURPLE AUTOMATIC SPEEDOMETER GEAR (43 TOOTH)

 

 

$15.00

 

 

AT6332Z

 

 

(1970 - 1981 Monte Carlo) GRAY AUTOMATIC SPEEDOMETER GEAR (44 TOOTH)

 

 

$15.00

 

 

AT6333Z

 

 

(1970 - 1981 Monte Carlo) LIGHT BLUE AUTOMATIC SPEEDOMETER GEAR (45 TOOTH)

 

 

$15.00

 

Dan

[AndyBill402]

Thanks to everyone for the information. I was going to work on the car this weekend, but it's raining and the temperature is going to be in the low 30's. So, I guess I'll just lose some more xmission fluid until it warms up a bit. I have a small pail strategically placed under the leak. BTW, I can't tell exactly where the leak is except that it drips off the speedo shaft where it screws to the transmision.

[wallaby]

Sometimes it's hard to see exactly where a trans fluid leak is. The fluid isn't dark enough and the background color of a cleaned trans case is also light in color...

I'd remove the speedo cable, then clean the area well with brakecleaner, let it dry, then dust the area well with talcum powder. Any further leaking will show up clearly. It will show up as red as it dampens the powder, or create a visible trail.

[bobsmc]

another common leak point is the selector shaft seal.

even the rebuilt one i bought from tci leaked.

i found that if you double up the seal[two seals] the problem is solved.mine would leak after sitting long enough for the converter to drain into the pan,which raised the level in the pan above the selector shaft.they are located on the same side so it is possible that it is leaking along the pan to the lowest point near the speedo housing.

 

bob