How do I identify my Tranny and Type of fluid to use?
I'm confused. I have a 1975 F350 RV w/ 460.
My automatic tranny was leaking from the pan gasklet. Should be an easy fix. Drop the pan and change the gasket.

In the past I have been told to use type F in older Ford trans.
The Haynes manual I have has confused me.
I thought I had a C6 tranny. no overdrive
Haynes Manual Ch 7B "...C6 for all other V8 engines. The FMX was installed on some F350 Vehicles until 1978.

Here is why I am confused
Haynes Manual Ch 1 -Reccomended fluids -
C6 = Dexron lll or Mercon
all others type F

 

Ok, forget the FMX, you have a C-6. Pre 77 models use Type F. 77 and later use Dex/Merc. If your transmission is an original 75, use type F. If the transmission is from a later model, or has been rebuilt using the later style frictions....use Dex/Merc.

 

Thanks, that's a relief. I bought 10 qt of Type F "Castrol" yesterday and a gasket.
I guess if I really want to know more about the FMX that was mentioned in the manual I'll start another thread . Another day.
I just found this info in an old thread.
I guess the Haynes Manual writers had a little to much to drink that day.

 

two part question

Part 1
If I presume that the C6 is original then Type F is the right fluid.
If the previous owner(s) had replaced or rebuilt it and it now requires Dex/Merc fluid, What bad thing will happen if I use Type F.

Part 2
I boughta Felpro gasket at Auto Zone. It is not cork like the one I took off. Might be a good thing.
It says do not use any sealant with this gasket. Is this a good gasket or is there something better

 

part 1

look at your dipstick tube does it say use type F? type f is similar to the fluid that is sold as trick shift for harder shifts so in a trans that wants mercon you'll see firmer shifts but in a trans that wants type f you might see some slipping

part 2

yeah that is a good gasket just be sure not to over tighten

 

Answer 1: Dex/Merc has a friction modifier...(it's more slippery). If you put it in a 76, it'll cause it to slip. If you put Type F in a 77, it will increase friction on the bands/clutches.....probably causing them to wear faster and/or shudder.

Answer 2: When you say sealant, are you referring to the stuff you squeeze out of a tube?? AKA RTV gasket maker?? Or, do you mean actual gasket SEALANT (the stuff in a spray can).

 

#1
I guess I'll find out. In 2 weeks I drive this beast to Phoenix and Back

#2 either one . I just want to to put this pan back on once with no leaks.

 

Ok, if in doubt, use the Type F. It's the lesser of the 2 evils.

Don't use any RTV on the gasket. However, some spray gasket sealant is probably a good idea......unless the gasket says specifically that the gasket should be installed dry.

 

WOW !!!!! You are my HERO.
I must have been having a senior moment.
I know I have pulled that dipstick more than once an read it.
This RV sits alot.

 

Thanks a bunch.
It does say use dry. I was just fishing for some tips and I got what I was looking for even though the answer was on the dipstick all this time.
I should change my name to "Dipstick"
I'm a regular user of a similar website "Jeepforum.com" and both have very knowledgeable and helpful people.
Now I have another site to burn my idle time with.
Thanks again

 

glad to help hope you enjoy the trip

 

Thread revival. I had a great trip. A few months after I got back the pan started leaking again. I hate leaks. It makes a mess on my driveway.
I used a torque wrench so I would not over tighten. I re-torqued the pan bolts again. It still leaks while just sitting there.
The hardest part about dropping the pan is removing and re-installing the frame cross member bolts.

any suggestions on better gaskets.


The pan just after I replaced it.



There is some minor leakage from the threads on this shift adjusting bolt I found before I changed the gasket.

and I have a small oil leak from the main rear seal on oil pan I presume, but that is also minor. It's making a mess in my drive way