I need axle shafts for my 78 f150 but I don't know what axle I have

 

If the differential housing doesn't have a cover like would an 8.8 or GM 10 or 12 bolt, then it's gotta be a Ford 9 inch.

 

Front or rear? Left or right? What's wrong with the ones you have?

 

Front - Dana44. Rear - Ford 9". The vast majority had 3.55 gears with open diff. The 9" had 31 splines. The D44 had 30 splines. Is this what you were looking for?

 

Likely 3.50 gears in a Ford 9 back and 3.54 gears in a Dana44 in front.

.... and how did you come to the conclusion that ya "need" to replace the axles/shafts???

 

I'd be curious to as to why you need new axles? The Ford 9" rear is a pretty tough rear end. Especially the ones with 31 spline axles. Not poking at ya but just curious. Or maybe you just want to upgrade the axles?

I'm not a driveline guru but to be sure I'd have a mechanic etc...take them out and double check everything. What I mean is in regards to bearing sizes. I know the 9" Fords had different bearing sizes. I want to say up to 3 different sizes. I don't know how it effects the axle it self or maybe it has to do more with the carrier etc..

I know when my mechanic (Dave) rebuilt mine and put a locker in it he went thru like 2 or 3 different bearing sets/parts houses before he found the right set.

Something to think about.

Later, Shortbox4x4

 

HIO is correct. If the rear end has three-fifty-something gears, it would be 3.50:1. There weren't any factory 3.55 gears for a Ford 9-inch rear end. 3.55s are more common to a Ford 8.8" rear end --completely different from a 9-inch rear.

Bearing type will be dependent on the GVW rating. The axle bearings could be sealed ball bearings or, they could be a tapered roller bearing for a higher GVW.

Tapered roller bearing on the left is on a 3,750# Daytona 31-spline axle from a '75 F150 4x4 9-inch rear. The sealed ball bearing on the right is on a 3,300# 31-spline axle from a '71 F100 Ford 9-3/8" rear end.



Probably the best thing to do is pull the axles and visually determine what bearing style it is and get the bearing numbers off of them.

If the front axle is a DANA 44, it could also have 3.50 gears.

 

Did the 9" ever use C-clip axles? More precisely, would they have ever used em in a 4x4 F150?

Seems unlikely due to the diff design, but Ford noobs (like me) gots ta know.

 

No C-clips in a Ford 9-inch.

 

I have a set of stock 31 spline shafts and a complete 3.50 geared open carrier if you're interested. Make me an offer. all parts should fit your '78 (they're out of a '77 4x4)