61olds88

Hello. Newbie here. Just picked up a 1961 Dynamic 88 with original engine and automatic trans. It appears to be leaking transmission fluid from some sort of joint or connection in the middle of the speedometer cable. See attached photo with arrow pointing to where the leak is. Im having a hard time finding what I need to repair this. I assume a new speedometer cable? The speedometer does work properly otherwise. Can anyone point me in the right direction or have part numbers for what I may need? Im sure this wont be my first post as there is a list of items I need to address on the car one by one. Thanks in advance!

61olds88

Edited my original post. It's not leaking at the trans connection. Its leaking from the joint in the photo in the middle of the speedo cable.

61olds88

Now I’m even more confused. Showed a guy that photo and he said no way is it leaking from there as the cable itself has no sealing function. It must be leaking from the connection/driven gear at the transmission. Weird because there is no fresh fluid there but definitely fresh fluid further down the cable near the point I circled. Anyway, where can I get a seal kit for the driven gear/trans connection point?

Olds64

That's a weird place for a transmission fluid leak. I thought the speedometer on your Oldsmobile was driven off of the front driver's wheel. You can check out Fusick to see if they have parts for your car.

https://www.fusickautomotiveproducts.com/

Here's a place to get transmission parts for your Oldsmobile if you ever have to go further in your restoration.

https://www.fatsco.net/

Charlie Jones

That was only on '63 thru '70 models.

Charlie Jones

There is an "O" ring and a seal at the speedo gear.
The fluid is leaking from there, and is running down the inside of the cable.

Olds64

Thanks for setting me straight Charlie.👍

61olds88

Thank you, Charlie! Any idea where I can buy those o-ring and seals? Doesnt seem to show the part numbers.

Charlie Jones

The part numbers are here in group 4.338.

Charlie Jones

Looks like 584059 .
Here's a link to FATSCO
Speedometer Seal (fatsco.net)

61olds88

Cant thank you enough! This American classic is not my normal wheelhouse. Im used to old Volkswagens, so its a bit of a learning curve for me to find parts and part numbers.

Charlie Jones

These free downloads will help.

1963 Oldsmobile Parts and Accessories Catalog (Chassis Edition) - ClassicOldsmobile.com
&
1963 Oldsmobile Parts and Accessories Catalog (Body Edition) - ClassicOldsmobile.com

WikedOldsmoileSupe88

I have the same issue with my car. I changed the main o-ring seal on the cable but not the small o-rings. Seems odd that the fluid leaks out of the plastic cable housing. Is the material porous?

To change the internal seals, I'm assuming you disconnect the speedometer cable from the transmission. But where is the small O-ring located. Is it in the end of the cable?

Thanks.