Dana 44 Power Lok question

There are two types of cross shafts listed for use in a D44 Power Lok.
The choices are either 45 degree shafts or 60 degree shafts.
Does anyone know why and when they made this change, or why there were even two choices in the first place?
Since all tapered axle 44s using Power Loks are 19 spline, seems that would rule out any 10 spline discussion.
Feel free to educate me.

 

Steeper ramp angle will apply force faster and be more harsh. Shallow angle will be smoother and less noticable.

 

Yea Ray I understand that.
But when purchasing a new power lok, you didn't get to choose between the two types.
Which also means the case is machined different as well?

So, maybe just a driveability/streetability desgin chnge then?

 

I seem to remember reading an article a very lo g time ago that said when Spicer started manufacturing them the angle changed from when Thornton was mfg them. It's kind of fuzzy though. I wonder if there's any info on Vernco.com?
I would think the shallower angle would also allow the clutches to tighten sooner as well as smoother. I've never seen one one with a different angle than the "standard" 45 degree angle but all I've assembled have been Spicer, Chrysler 8 3/4", or aftermarket units. Never built a Thornton afaik.


Sent from my iPhone

 

Absolutely Yes.
The case ramps must fit the pinion mate shafts.
One can not simply buy different case halves to fit pinion mate shafts because the case halfs alone were never available.
Case halfs were only available with a complete assembled Powr Lok unit.

In earlier parts lists these were referred to as 30* shafts and not 60* shafts as the later parts catalogs will indicate.
These earliest 30* pinion mate shafts are referred to as jeep part number 912636.
That number indicates that they were in production by very late in the 1956 model year.

Also realize that Jeep part numbers 912625 and 912626 came into existance at virtually the same time.
Those 2 particular numbers refer to the left and right 19 involute splined tapered axle shafts.
This reveals that the 19 splined shafts were specifically developed in conjunction with the early Powr Lok units.
I'm not stating that there were no 10 spline Powr Lok units that were ever developed.
I'm indicating that early Powr Loks for CJ's were all equipped with the 19 spine axle shafts.
No 10 spline Powr Lok units were ever in production for the CJ's.

The later 45* Powr Lok pinion mate shafts are refered to as jeep part number 921383.
That number suggests that all Powr Lok units were changed in 1959.
The 19 involute splined Powr Lok units were never changed again after that.
IMHO these 1959 and later 19 spline units are certainly some of the best Powr Loks ever devised.
The only thing tougher for an OEM Dana 44 would be the relatively rare 30 spline units.

When the IH Scouts were developed in the early 1960's they were way ahead of Jeeps when it came to Spicer Powr Loks.

 

How about vehicle weight rating? Heavy truck slower ramp?

 

I seriously doubt that GVWR has anything at all to do with Dana Spicers decision to change the angle of the case ramps.
GVWR is mainly a concern of the chosen axle model such as D23,D25,D27,D30,D44,D53,D60 or D70.

The Thornton Powr Loks were initially developed for the Dana 44.
It was not until later that Powr Loks were ever developed for other Dana models.
Example: the Dana model 25 axle had been around since 1941 yet the Dana 25 Powr Lok was not developed before 1959.
The Powr Lok was yet a relatively new developement when this 1959 change of the ramp angle went into effect.
All other models of Powr Lok including D23/D25, D27, D30, D53 and D60/D70 use the same 45* ramp angle that became standardized in 1959.
So the only 30* ramped D44 Powr Loks were from the very earliest production years only.

This related post may be of interest: http://z4.invisionfree.com/CJ3B_Bulletin_Board/index.php?showtopic=2878

 

Does anyone know of or have a reference for the Dana numbers stamped into the power lok case halve?
An example would be: Dana 25 23321 X or Dana 27 22477 X.
The dates of manufacture stamped into these are self explanatory.
I'm finding some NOS units that appear to be identical applications yet these numbers are different between the two units.
Was there a printed Dana guide to identify these numbers?
I do understand the front axle/rear axle application differences, with open hole cross shafts and axle spacer buttons for rear axles, no holes or buttons for front axles.
Anyway, is their any info out there?

 

I have never seen any Spicer references to their Powr Loks.
But I have jotted down several, maybe a half dozen Powr Lok numbers.
Evidently both the Date Of Manufacture and the application will effect the number stamped onto the case.
I'll try to look for those numbers.

While I'm on the topic; many of you know... the two case halves must be kept together since they are drilled as a unit.
In fact these case halfs must be re-assembled according to their original orientation.
The original case halves orientation was not marked at the factory.
It's readily possible for one to attempt to assemble the case halves 180* from their original orientation.
In that instance the long case bolts will not enter smoothly into the threads.
If case halves do not assemble smoothly, one should rotate one of the halves 180*.

 

Here are some numbers I've run across for the various power lok units for future reference, I didn't list all ratios known, just the most popular.


Dana 25, 4:88, 5:38, 10 spline, solid cross shafts, 23321-X, DOM 4-2-86
Dana 27, 4:10, 4:27, 5:38, 10 spline, open cross shafts with buttons, Scout rear axle, 22477-X, DOM 8-30-66
Dana 30, 3:73-5:38, 27 spline 24801-X , DOM 8-10-78
Dana 44, 3:73 , 19 spline, open cross shafts with buttons, 23116-X, DOM 12-7-65

 

i have some bom (bill of materials) pdf's i can send you. it has powr-lok #'s for you.

 

tells what it came in i.e scout, jeep, chevy, ford, dodge

 

i can mybe e-mail them but it is not cooperating right now and not sure why

 

I think I've seen those
pm sent
does it have the X numbers?

 

Dana 25 Fits all D25 ratios 4.09, 4.27, 4.88 and 5.38
I have qty (2) #23321X DOM = 8-20-79 and DOM = 7-8-84
These were produced as early as 1959 so other X numbers likely exist.

Dana 27 Series 4 (STD) 3.92-5.38
There are a couple #22477X posted on the forum ranging from DOM = 1-6-64 to 10-1-68.
The D27 axle began no earlier than 1961.

Dana 30 Series 4 3:73-5.38 27
One #24801X case number DOM = 8-10-78

Dana 44 19 spline Series 3 (Auto) 3.73 and higher
One #23116X posted on forum DOM = 12-9-68
One #22017X posted on forum DOM = 12-18-0

Dana 44 19 spline Series 4 (STD) 3.92-5.38
One #23181X of mine DOM = 4-29-63
One #21920X of mine DOM = 2-17-83

Dana 44 30 spline Series 3 (Auto) 3.73 and higher
One #26846 posted on forum DOM = 7-11-68

Dana 44 30 spline Series 4 (STD) 3.92-5.38
I have qty (2) #25565X DOM = 7-18-69 and DOM = 11-17-70

 

yes it does. and the case half numbers etc. if i remember correctly.

 

i sent them to ya. hope they work

 

thanks John
Haven't had the time to go thru the info yet.