64 New Yorker with a 727

GORDON DREW

New Member
Joined
Oct 26, 2021
Messages
23
Reaction score
21
Location
Kawartha Lakes, Ontario
What’s everyone using for transmission fluid?? I’ve got people telling me to use ATF+4 or Type F. The pan gasket is leaking so i might as well replace the filter and fluid while i’m at it. Thanks for your help.
 
I use ATF+4 for my 64 NY, but to each their own I suppose. There's tons of back and forth about which tranny fluid to go with if you look through this site.
 
On a well used transmission, stick with ATF-3. Atf-4 is a superior fluid, but it is a full synthetic and can break loose a bunch of accumulated crud. Type F provides a firmer shift, but unless you are a hot rodder, you do not need to worry about that on a cruiser. Type F also has a shorter fluid life than ATF -3.
 
On a well used transmission, stick with ATF-3. Atf-4 is a superior fluid, but it is a full synthetic and can break loose a bunch of accumulated crud. Type F provides a firmer shift, but unless you are a hot rodder, you do not need to worry about that on a cruiser. Type F also has a shorter fluid life than ATF -3.
So of i go this route, be prepared to drop the pan before the end of the season?
 
The pan gasket is leaking
Make sure it's the pan gasket and not the throttle shaft seal. Those seals can get bad and the fluid runs down the side along the pan mimicking a pan leak.

If it were me, I would think about dropping the valve body and changing that seal. It might be able to be changed with the valve body in place, but I've never looked into that myself. The only issue is adjusting the cables afterward if you dropped the valve body. .

(For those that are going to say about the tool to change the seal in a LATER trans without the cable shift, that's not going to work)
 
The cable shift doesn’t have the same shift seal as a 1966 and up linkage **** TF. No need to remove the valve body on a cable shift to replace O-ring seals. Adjusting the cables is easy with the factory service manual.

The cable shift has many o-rings to seal the cable, Throttle pressure shaft, speedo, park cable, etc. Then the neutral safety switch and the rear band pivot shaft O-ring that many rebuilders don’t change. The cables can leak fluid also.

ATf leaks can be tough to find. And stuff runs down hill so it could be something above the pan.
 
The cable shift doesn’t have the same shift seal as a 1966 and up linkage **** TF. No need to remove the valve body on a cable shift to replace O-ring seals.
I'm talking about the throttle shaft seal and not the shifter seals. IIRC, the throttle shaft seal is the same as the later seal, difference being that the later trans has that seal in the valve body (the shifter shaft) while the seal in the cable shift presses into the case. No, it's not the same as the shifter shaft seal on a later trans.

At least that was the case in my '65 904.

Can that seal (throttle shaft) be changed with the VB in place? It would seem to me that it could be... I never looked into it because I was taking out the VB to install the bits and pieces needed for a "part throttle downshift" mod.
 
Make sure it's the pan gasket and not the throttle shaft seal. Those seals can get bad and the fluid runs down the side along the pan mimicking a pan leak.

If it were me, I would think about dropping the valve body and changing that seal. It might be able to be changed with the valve body in place, but I've never looked into that myself. The only issue is adjusting the cables afterward if you dropped the valve body. .

(For those that are going to say about the tool to change the seal in a LATER trans without the cable shift, that's not going to work)
I had the car up on the hoist before i quit the dealership I was working at. It’s the pan gasket for sure.
 
Get an OEM pan gasket, I've tried the cork type and they just immediately leak. These transmission will work on just about any type of trans fluid, but just beware of mixing fluids that aren't compatible.
 
Back
Top