The C4 Dana 44 is actually called a super Dana 44 and it uses the same ring, pinion & carrier as the viper unit. The only difference is the case.
The super Dana uses a Dana 60 sized pinion, where the C4 D36 & the C3 D44 both use the smaller sized pinion. These 2 use the same sized pinion but different sized ring gears. The carriers are even interchangeable (I have a C3 D44 w/ a C4 D44 carrier with the 8,5" ring gear)
C3 D44
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Pinion Shaft Diameter: 1.375"
Pinion Spline Count: 26
Ring Gear Diameter: 8.5
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 10
C4 D36:
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Pinion Shaft Diameter: 1.375"
Pinion Spline Count: 26
Ring Gear Diameter: 7-9/16"
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 8
C4 D44 HD/V/Super
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Pinion Shaft Diameter: 1.625"
Pinion Spline Count: 29
Ring Gear Diameter: 8.5
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 10
The C4 D44s are not all alike either. Supposedly the early housings are stronger. There are 3 versions, the differences can be seen by the ribs in the C beam pad and the other stiffening ribs. The early batwings are stronger also.
The C4 D36 is easily identified by that it has a single top mounted cover bolt, the 44 has 2 bolts on the top, much like the C4 unit.
the C4 and C3 housings and batwings are not interchangeable between either C3 D44, C4 D36 and c4 D44.
The camber brackets for the C4 (2 separate pieces) will bolt up to the C3 unit, the C3 unit's single large bracket will not bolt up to the C4 unit because there's a bulge in the casting.
C3 D44
C3 D44 w/ C4 D44 case (see no c clips to retain center pin)
C4 D44
C3 vs C4 D44
3 versions of the C4 D44 case
The C3 D44 case, including measuring pinion depth and a case spreader.
A C4 D44 with a spool
Another thing to note is that the C3 D44 uses CAST bearing caps and that the housing is NOT machined for the cap seating surface, it is AS CAST.
The C4 D44 does have machined surfaces and the caps are forged aluminium. I'm not sure about the 36 though.
Another thing which is different between the C3 and C4, apart from the obvious that the C4 uses a C beam front diff mount, is that the C4 batwing is narrower (both D36 & D44), it's narrower by exactly 2cm. You can easily modify the 80-82 frame brackets, the C4 one will fit after you remove the 2 square alignment blocks.
The C4 differentials will
NOT bolt up to the 80-82 batwing.
Here's a complete C4 Dana44 in a C3 with a custom pinion mount. The holes in the frame brackets were simply enlarged for fitting & testing purposes, later theyw ere changed for new fabricated parts.
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