[QUOTE]Then there must be more then one version of a 50 because the lower ball joints aren't smaller in the 50 IFS I have then the 60 I have. They are the same joint. I went to the shop and looked. I don't have the measurements of the the axles in a 60 but the 50 I have the axles are 1.450". They are alot bigger unit then the 44's . THe 50 I have is out of a late model super duty. The differences you are showing isn't what I have.




D50 Joint beside the 60:


D50 cap beside the 60:

 

I wish I had taken a few pictures of what my engine can do to a 44 axle while sitting on glare ice.
They would not have been nice to look at though.

Have you ever seen a yoke with the ears twisted off?
I also had some really cool looking U joints, I would have had to tell you what you were looking at they were so badly mangled.

Think exploded fragmentation grenade for a visual on the U joints, that should get you close.

 

For what it's worth, here are the output torque ratings for the 44/50/60 as listed in the 1982 and 1999 Dana axle systems specification catalog:

Dana 44IFS- 3,450 lbs-ft (max short duration). 1,100 lbs-ft (continuous)
Dana 50IFS- 5,000 lbs ft (max short duration). 1,200 lbs-ft (continuous)
Dana 60F- 5,500 lbs-ft (max short duration). 1,500 lbs-ft (continuous)

Output torque is essentially the amount of traction torque, or tire grip, that the axle can hold before something breaks. The engine torque, multiplied by the gearing (500 lbs-ft x 3.0:1 first gear x 4.10:1 axle ratio= 6,150 lbs-ft ) is pitted against the traction torque. If you can generate enough grip to hold the 6,100 lbs-ft your engine is generating and your axle is only rated for 5,500, then snap-crackle-or-pop (and it ain't Rice Crispies). Fortunately, seldom can tires generate that much grip, but using Dave's snowplow example, you see there are exceptions. You put a bunch of weight (a big plow up front) onto two big, sticky tires (weight x coefficient of friction= grip) and downstream of a torque-monster engine and some gearing multiplication... wham-o!

Note: The Dana 60F rating would be much higher but for it's small 30-spline outer shafts and the relatively weak hubs. A Dana 70 front, which is very similar and uses the same inner shafts and u-joints, is rated for 8,000/2,000 lbs-ft. The major difference, besides a bigger ring gear, (that doesn't contibute all that much to a high maximum torque rating if the gear ratios are inside the test envelope, though a bigger ring and pinion does add a lot to the continuous rating) is the 35-spline outer shafts and stronger hubs. I was told by a Dana engineer that at least 1,000 lbs-ft (and maybe 1,500) of that maximum rating difference between the D60F and D70F was the outer shafts and hubs. Those numbers hold up on paper too if you work the axle strength formulae.

FYI, Ford (Visteon) rated the 10.25 rear axle at 8,300/2,000 lbs-ft. The later 10.50 is even higher, at 10,660/2,900. Those rating have a lot to do with the 1050 high carbon steel alloy axle shafts that Ford has used for many years.

 

BTW, forgot to ask. Does anyone have a Dana 50 shaft pulled? If so, tell me if it has the necked down section outboard of the splines like a dana 44?

 

Sorry about that Catfish, I was talking in reference as to what was available in these trucks from the factory.
A Super Duty D50 solid axle is not related to a 50 TTB other than sharing the same ring/pinion and carrier.
First off, it's a solid axle, not IFS, and it is based on a 60 housing, so, it has 60 joints, ball joints, hubs and outer axles. Inners still neck down to 44 size at the diff.
I used to own a 00 F250... Replacing all 4 ball joints and one unit bearing in one shot was enough for me, that combined with truck and insurance payments broke me(was 20 at the time...)
If what you have under your truck is IFS with D60 sized ball joints and U-joints, I want pics, I have never, ever seen any reference to such an axle before

Dave, yes, I have, been there done that with my diesel, too bad I threw the axles away without taking pics... I need to get my other 60 together and in that truck soon... That and my buddy used to have an 84 F150 on 35's with a 350 horse 351W and a 4 speed with a welded front diff... It broke axles left right and center until his lead foot got the better of the poor engine in a mud hole after the front exploded yet again and he got stuck...

Jim, I don't have one loose at the moment, but, here's a pic of the DS inner:

 

If this is from an IFS, then it's what I was looking for, thanks. It doesn't appeare necked but has a thicker section in the center.
I have specs for a D50IFS axle, but they never list the diameter of the necked section, which is the weakest part. On a D44, it's 1.10-in, a little less than the minor spline diameter.

 

Yup, that's IFS stuff, note the external snap ring groove.
I'll see about yanking mine apart here this afternoon and grabbing you some measurements...
I'm currently planning on seeing if I can't stuff a High Boy kingpin 44HD(same u-joint) full of 30 spline D50 stuff for the heck of it...

 

Well, don't tear it apart on my account... but if you are in there, I'd be interested to know. Thanks.

 

The axle I kept breaking was the outter stub axle.
The only time I had problems with the inner shafts was damage done after the outer axle broke or after the U joint broke.

Then there was the year the the right side 44 housing broke while plowing, broke right beside the pivot bolt.

285/75-16 Bridgestone Dueller RMT (Radial Mud Tire) can get enough traction on snow covered roads to smoke a 44 axle with ease, and I have 3.55 gears.
I started using the cheapest hubs I could find after I broke 3 ot 4 axles, it was much easier and cheaper to replace the hub than it was an axle.

 

I will get a pic posted. I have the fenders off the truck now because of painting.

 

I didn't break an outer stub, I broke the DS inner and the pass side, umm, middle(for lack of a better word) one, then I stopped fixing it

 

Sounds like we are in the same boat, and both of us are now glad the IFS 44 is gone.