Offset D44 locking differential info

I'm looking for help with identifying the spicer number for the factory locking differential that would be stamped on the carrier.

I just removed the cover and found 26988 X with date stamp 4 15 70A. Is this an open carrier or locking? Upon inspection inside I see something that appears like clutch disks on one side.

 

One type of locking diff is called the powerloc; the case has two halves which are bolted together with 8 bolts. There are small "window" openings which let you see inside. The numbers you have posted are usually stamped into the case half with the bolt heads showing, or the more "machined" surface. I believe, based on the numbers, you indeed do have a powerloc.
The open or standard diff allows you much more visual access; the case is a one piece design, no bolts. You would be able to see almost all of the spider gears and shaft with this diff.
I have been trying to work on a list of the numbers you have given, but so far haven't "got 'er done".
Is your axle tapered axles, or one piece flanged axles?
Tapered axles would use 19 spline spider gears, while the flanged would use 30 spline gears. But they work in the same fashion with clutch plates/discs, that require special additive added to the gear oil.
The powerloc was available as a factory option as well.

 

powerloc (couldn't find the JPEG of mine so stole this one )

 

yep
that's the one
thanks Jon

 

I have the offset flanged 30 spline D44.

It is definetley a one piece meaning the two halves do not bolt together. It also is very exposed like an open carrier. I download the picture from this ad ( http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4538972834&category=42611 ) and upon enlarging the picture you can see the disks that I think are clutches on the none ring side.

If anyone knows of a list that jpflat2a is refering to I would like to check it out.

 

That unit pictured in your post appears to be a Trac-Loc
1 piece case, clutch design
more commonly seen in 72-75 D44s
in my opinion, not as strong a unit
the case can break in half

 

Was the Trac-loc a factory option in the ECJ5? This one is pretty correct on the date stamp.

 

powerloc for 1971 and prior models
1972 and later used the Trac-Lok
is your case 1 piece or 2 piece bolt together halves?

EDIT: never mind -re-read above

 

well I stand corrected
according to the parts book, the Trac-Lok was offered with the beginning of the flanged axle, so that would be 1970-1971
so what you have is most likely factory
sorry for the confusion

 

Thanks for the info.

Now what do I need to go to 5:38 gears in the way of the powerloc?

Series and part number??

 

you need to find a D44, 4 series, 30 spline for flanged axle
this would work for 4.10, 4.27, 4.88, 5.38 etc
they are on ebay for about $279 new (can go higher depending on bids)
search: Dana 44 Powerloc (k)
also IH Scouts 800B 4x4 used the same powerloc I believe
(but I have been wrong before)