I've a EB C4 with 10.4" bolt pattern torque converter. Does it have a harden input shaft?

I pulled an input shaft out of a 79 F150 2WD with a C4 (Dipstick in the pan) I believe it's a hardened input shaft but it was re-built.

So How do I tell a hardened input shaft form a regular one?

I don't know how you'd tell if it was hardened without the proper hardness test equipment, but I don't believe that the C4 input shaft is hardened. It is a common upgrade during a rebuild so I'm told.

ARokCrwlr,

Some C4's came from the factory Hardened. I've read the Truck C4's were. Also that the Heavy Duty C4's had the dipstick in the pan.

However I'd like to know as If I'm swapping them doesn't mean someone else didn't before me.

Anyone?

Mr N. this trick might be of use. take a file and try to file the end of the shaft. if it can't cut the metal ( assuming the hardness is higher than the file) then it is hardend. if it cuts the shaft then probably not. There are file sets made with graduated hardness for field checking harness on the Rc scale. The theory being if the piece in question is harder than the file then it can't/won't produce shavings.
Do NOT try to file the shaft along the length or the side of the splines, this will set up a weak stress riser.
I did not know there were two different hardness for the C-4 shaft.

Eric

Alpo23,

Thanks for the idea. I check it out.

I though there should be some kind of mark on the metal.

Fill tube in the pan means that it is an early c-4. In 69-70 they went with an intergrated fill tube into the case.

I thought the 70's C4 with a pan dip stick ment it was a Heavy Duty option.

This C4 was out of a 79, My EB C4 is a 73-75 C4 and has the dip stick in the pan.

What is the heavy duty option? Last time I was inside one the only diffrence I found is that the pinto has a diffrent valve body, and more clutches inside the drums. Then I use a diffrent pressure pate in the drums and get an extra clutch in there. Install a shift improver kit and your in the house.

One other thing, make sure you are not looking at an FMX. They have the cast iron main housing.

Can't find it now, but I read some where the dip stick in the Pan was a HD C4.

Ford Auto Tranny stuff here.
http://www.usaplaza.com/scripts/wcom_producttree.asp?StoreID=1078&ProductID=32342

Ok, called some shops. They only guy who was knowledgeable about the C4 I could find did say he believed the rumor of the 78-79 trucks having a harden input.

Well this was a rebuilt, tried the file think, neither seem to be hardened. O'Well at least I've a spare.