[zero66]

i just got a 1966 mustang coupe with a 289 and c-4 transmission in it and i was wanting to dump the fluid out of the transmission. my question is what kind of fluid should i put in it and how much does a c4 hold. thanks for everyones time

[redrulz]

Original calls for " type F " transmission fluid.
Whether to use synthetic or not? I had a discussion on this with a rep from one of the synthetic producers. His recommendation was to use original type unless you've done a complete rebuild with new seals etc. Reason being is that synthetic is much freer flowing ( less viscous )than original type and will leak past worn seals. If you've done a complete rebuild then consider making the switch to synthetic.
Shop manual says that after you've dropped the pan to be sure and install a new gasket and screen before re-installing the pan. Add 3 quarts of fluid thru the filler tube, run engine at idle for about 2 minutes, check and add oil if necessary. Run engine at fast idle ( about 1200 rpm ) without racing the engine until its up to normal operating temperature.Run selector thru all positions, place in P position and check level. Add enough to bring up to full mark. DO NOT OVERFILL.
Ted

[Ivy66GT]

Book says 8.8 quarts for complete refill but a complete drain of a 66 C-4, including converter, only takes about 7 1/2 quarts to refill. Type F.

[zero66]

thanks for the help guys

[66Sprint200]

I just put a new transmission pan on my C4. I used Castrol ATF transmission fluid for my trans.