1974 Ford 9 Inch, 28 or 31 Spline axle shafts?
 

My friend has a 1974 F-100 Ranger. The previous owner said it had a 390, but the V.I.N tells us it has a 360, so I'm not shur on that one.

anywayyyyy...

He is looking at a spool locker for his truck, for the Ford 9". Does anybody know if it has 28 or 31 spline axle shafts?

Sorry I can't provide more info, that's all I know right now.

Thanks! :-X25

Well I would guess its a 31 spline simply because it is a truck axle. Although I am not sure about the F100s. Fastest way you can find out is remove the wheel, brake drum, unbolt the axle (4bolts) and pull it out. The 28 spline axles are tapered and the 31s are not.

As for that engine all you can do is look at the rear of the crankshaft for determining the stroke, unless, you want to tear it down n look at the crank casting number.

1973/74 F100's without Limited Slip offered both 28 and 31 splined axles. Both are the WDM type.

If the Ford ID tag is still on the rear end, the tag code prefix will be WDM. Whatever the suffix is, will tell whether it has 28 or 31 splined axles.

Another way is look on the Warranty Plate, left door face below the latch for the AXLE code.

IF the rear end hasn't been changed...the code will tell...once it's decoded, what the rear end is.

The rectangular shaped tag is under one of the carrier bolts (pumpkin). The tag usually is at 5 o'clock.

Hey guys im the friend ... lol
any help is good help thx guys

We decoded the V.I.N using the decoder on this website, yielded no result's as to the model for some reason.

VIN: F10YCU28073

GVWR: 4850 GAWR FR: 2680 REAR: 2836

We found (not shur we read them right,) but...we found 344(2) (not shur about last digit) and 40A ?? No luck decoding those.

Always pull the axle if you are not sure, it is pretty easy to do for the 9 inch. I do not think I would run 28 spline with a spool anyways.

360s always become 390s when they want to sell the truck. I knew nothing about FEs (except the 351 air cleaner was wrong) and my 1971 4x4 which never should have had a 390, since it only came from the factory with a 360, actually was a 390 from a 1965 Galaxie 500.

Easiest way is pull a plug and measure the stroke, 4" = 390. About 3.5 = 360?

You can decode the heads, that helps sometimes.

I dropped the pan and saw the 2u crank.

Alright, thanks for the help. We are going to go ahead and pull one of the axle shafts out and check the spline count.

Thanks for all the help!:-X25