1967 ford mustang

I changed my transmission oil today,dropped the pan, replaced the filter, etc. Problem is, I used an oil from “Supertech”, automatic transmission oil (it comes in a blue gallon jug). Only after I made the change, did I read on the back label: “do not use in transmissions that specify FORD TYPE F”. I checked the manual on my 67 Mustang,it’s a FORD TYPE F. What kind of problem might I expect if I drive on this oil? Should I really replace this oil (I’m doing this myself, it’s not easy for me with the jacks, etc,) There’s no customer support tel # on the back of the (now empty) Supertech jug.

Can someone help?

thanks alot, joe

I’d advise draining the fluid immediately. For the sake of the transmission I’d even consider towing the car to an independant trans shop and get the transmission flushed out in an effort to get as close to 100% of the Supertech fluid out as possible. Pulling the pan and draining it youself will only get about 50% of the fluid.

Since the label says do not use in Ford Type F you know the fluid is incompatible with the transmission. How soon and how much it will damage the transmission is hard to predict, but you know from the label it isn’t going to do any good for your transmission.

This is a classic car at this point. How easy or hard is it to get this transmissioin rebuilt or replaced with another one? Do you want to find out? Get out the jacks and get to work or better yet, get it professionally flushed by someone who knows how to do it properly.

Go to trans place NOT quick lube place!

If you haven’t started the engine at this point, just drop the pan again and replace the fluid with ‘Type F’ Type F has a different friction characteristic that matches the friction material used in that transmission. If the engine has been started, you will have to flush the fluid out of the torque converter. It is possible that the TC has drain plugs. I don’t know when Ford dropped that feature.

Hope that helps.

At least some Ford sedans had TC drain plugs up to 2002. OP, you can drop the pan, drain the TC, pull off the cooler lines and pump the fluid out by starting the engine.

As pointed out, if you haven’t started it up, just drop the pan again. If you have, after you drop the pan, remove the cover from the bottom of the bellhousing and bump the starter until you can see the drain plug on the torque converter. Bump the engine or turn by hand until the plug is at its lowest point and remove and drain the torque converter. Replace the plug, cover and pan and fill with type F

Start the engine with no oil in the transmission???

Don’t do that.

It works with modern transmissions. Is it bad for the '67?

The Dexron/Mercon fluid you put in will not hurt the transmission per se, but it will make it shift way to “soft” almost to the point of slipping. You will have to drain the fluid and YES, there WILL be a drain plug on the torque converter so you can drain 95% of the fluid and replace it with type “F” fluid.

thank you to all for your replies…
I will drain the all of the fluid, including out of the Torque Converter.

Just FYI,I spoke with a fellow who’s owned a Citgo garage for many years,says the Dextron fluid I put in will be OK for the car. He owns an old Musang himself, and uses Type III Dextron (that’s what I put in), and has no problems. Maybe he doesn’t drive it often enough.,I don’t know…

Anyway, thanks again


The Fords of years ago shifted very harshly, especially compared to GM and Chrysler automatics of the same vintage. That’s because the friction materials: clutches and bands, were very thin. These materials were maybe 25 to 30 percent the thickness of their GM and Chrysler counterparts. This meant that there could be very little slippage allowed during their engagment, and that meant that they had to shift in a very positive, if harsh manner. The type F fluid assisted with this: it has a lower lubricity than the Dexron fluid. That’s most, if not all of the reason not to use Dexron in a Ford transmission.

There was also an aftermarket fluid at the time marketed by B & M, called “Trick Shift”. Among other things, it had a still lower lubricity, and made transmissions shift even harsher than the Ford fluid did. I haven’t looked in years and years, the stuff might still be around.