dana 30 powr-lok id

i bought this unit from a member here a bit ago and am trying to make sure it is what he said it was. i was told its a dana 30 powr-lok with a build in 69 and a number of 25244x. i've looked in all my spicer pdf's and no luck finding that number. he told me it was for 3.54 and numericly lower gears.
can anyone help me find out what this is? it almost looks like a dana 27 powr-lok though.

 

sorry, i think i put this thread in the wrong category.

 

Physically a D30 Powr Lok unit is only slightly larger than D25 and D27 units.
In fact D25, D27 and D30 units all use the same identical friction disk sets.
However the case outside diameter is a bit larger on the D30 units.
The D30 will accept 27 spline shafts while the D25 and D27 units accept 10 spline shafts.

Often times but not always the case markings will identify the series.
STD = series 4
AUTO = series 3
For D30 3.54 and lower numbers you need AUTO or series 3.

If you cannot find those case markings I suggest you place on a flat surface.
Measure and record the distance from the side bearing shoulder to the ring face.
I'll measure my Dana 30 series 4 unit for comparison.

 

Also the D30 uses 10 bolt ring gear while D25/D27 use 8 bolt ring gears.

Measured distance from the outer bearing journal to the ring face.
For a series 4 model 30 differential it is 4.75".

 

thanks ken. i just got a 4 series for the 30 and if the other one is in fact for 3.54 gears it's got to go.
i will go out right now a measure that other case i have.

thanks a bunch!

 

ok went out and measured both.......the one i'm wondering about is 4 13/16" and the series 4 case is 4 5/8" (which i know it is by the numbers). the bearings are on both units and sitting on flat surfaces. so......

 

Wow talk about splitting the difference.
Those numbers are on either side of my measurement.

My measurement did not include protrusion of the bearing cone nor the bearing cage outward from the journal.
Measurement taken from the bearing cage is effected by the bearing shim pack.
If we use a dissimilar method for measuring, then the inconsistent procedure will yeild variation.
I set the differential case on my work bench with the ring face positioned upward.
I place a straight edge across the top journal and then measure straight down to the ring face with precision calipers.
The journals are always shimmed so the measured tolerance to that point will always be slightly inconsistent.
I expect that the required tolerances were oriented outward from true centerline of each unit.

Anyway....
The pinion diameter increases plus the ring gear thickeness decreases and the ration goes up.
(higher / numerically lower)
This is the reason for building seperate series of differential cases.
So that the ring gear does not become excessively thick nor thin.
And also that the pinion does not become excessively small nor large.

I don't have any series 3 stuff to measure but....
I would expect series 3 and series 4 to be about 3/16" to 1/4" difference.
The series 3 case must move the ring away from the pinion in order to increase the ring thickness.
Therefore the series 3 ring face will measure further out from the edge of the journal.

Got that ?

 

i figured the bearings and the shims would affect the measurements but i do not have a bearing puller to remove them. so made due with what i had.
the bearing on the face side of the unit is pressed down enough to where the journal is higher so i did the measurement just like you did with the face side up and using a straight edge came up with 4 11/16" so 1/16th shorter than yours but it's still a 4 series case according to the numbers from the case. the other unit is in the barn and too late to monkey with it tonight.
if i'm going to sell that series 3 case i need to know it is one before i sell it to someone and it not be the right one for them. i purchased it from a member here and am taking his word at what it is. i just cannot find any numbers in my spicer pdf's that match what is on the case.

i just did a search and there is a unit with the same numbers on epay right now stating it is for 3.54 and down so there i go. problem solved.

i really wish i was as versed in this as much as some of the people here. thank you for your explanations. i knew it was something like that with the thickness of the gear and the case needing to be different size. you learn something new every day. what a wonderful life it is.

 

I don't have the Powr Lok blueprints but...
As I was saying the cases are likely referenced from the case CL.
The journal stick out from case CL is not highly critical because the bearings are shimmed out regardless.
Besides that cases were manufactured over an extended time duration.
Staying within the blueprint tolerance is all that matters.
So your case measures at 4-11/16" and mine measures at 4-3/4".
That small difference is to be expected for two reasons.
1) Variables of measuring instruments and techniques.
2) Unknown blueprint reference point and unknown toleraces for the various dimensions.

Anyway now you know how to determine the difference.

 

thanks very much ken. your awesome.