UNITRAX DIFFERENTIAL ASSEMBLY SPECIFICATIONS

 Differential Model
 Pinion Bearing Preload
(Inch lbs) (N.m.)
 Preferred Backlash
(.001 inch) (mm)
 Ring Gear Bolt Torque
(Foot lbs) (N.m.)
 Bearing Cap Torque
(Foot lbs) (N.m.)
 AMC
 Model 15
 20 - 40 (2.3 - 4.5 )
 5 - 8 (.13 - .20)
70 (95) 
50 (68) 
 Model 20
 15 - 25 (1.7 - 2.8)
 5 - 8 (.13 - .20)
52 (71) 
57 (78) 
 GM
 63 - 79 Corvette
 20 - 25 (2.3 - 2.8)
 5 - 8 (.13 - .20)
 50 (68)
 55 (75)
 7.5" / 7.625"
 24 - 32 (2.7 - 3.6)
 5 - 8 (.13 - .20)
 90 (120)
 55 (75)
 8.5"
 20 - 25 (2.3 -2.8)
  5 - 8 (.13 - .20)
 60 (81)
 60 (81)
 8.875"
 15 - 20 (1.7 - 2.3)
 5 - 8 (.13 - .20)
 60 (81)
  60 (81)
 9.5"
 20 - 25 (2.3 - 2.8)
 5 - 8 (.13 - .20)
 105 (142)
  60 (81)
 10.5"
 23 - 35 (2.6 - 4.0)
 5 - 8 (.13 - .20)
 120 (163)
 135 (184)
10.5" Drive Pinion Nut - Tighten as necessary to obtain correct preload.
10.5" Pinion Bearing Retainer: 65 (lb/ft) 84 (N.m)
 Chrysler
 7.25"
15 - 30 (1.7 - 3.4)
5 - 8 (.13 - .20)
70 (95)
45 (61)
8.25 "
 20 - 30 (2.3 - 3.4)
 5 - 8 (.13 - .20)
70 (95)
 100 (136)
 9.25"
  20 - 30 (2.3 - 3.4)
 5 - 8 (.13 - .20)
70 (95)
 100 (136)
Dana Spicer
 Dana 30
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 55 (75)
 50 (68)
 Dana 35
  20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 70 (95)
 50 (68)
 Dana 36ICA
 15 - 35 (1.7 - 4.0)
 5 - 8 (.13 - .20)
 70 (95)
 45 (61)
 Dana 44
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 55 (75)
 70 (95)
 Dana 44ICA
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 70 (95)
 60 (81)
 Dana 60/61/70U
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 110 (150)
 80 (108)
 Dana 70/70HD
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 110 (150)
 80 (108)
 Dana 80
 20 - 40 (2.3 - 4.5)
 5 - 8 (.13 - .20)
 220 (298)
 80 (108)
Ford
 7.5"
 16 - 29 (1.8 - 3.2)
 5 - 8 (.13 - .20)
 70 (95)
 70 (95)
 8.0"
 16 - 29 (1.8 - 3.2)
  5 - 8 (.13 - .20)
 70 (95)
 70 (95)
 8.8"
 16 - 29 (1.8 - 3.2)
 5 - 8 (.13 - .20)
 70 (95)
 70 (95)
 9.0"
 16 - 29 (1.8 - 3.2)
 5 - 10 (.13 - .25)
 70 (95)
 70 (95)
 9.75"
 16 - 29 (1.8 - 3.2)
 5 - 8 (.13 - .20)
 100 (136)
 70 (95)
 10.25"
 16 - 29 (1.8 - 3.2)
 5 - 8 (.13 - .20)
 100 (136)
 80 (108)

   
PINION DEPTH  
   
Use the following group of shim thicknesses as a starting point only if you do not have access to a depth gauge or have lost the original shim from the old pinion:
   
GM: .035

FORD: .020

DANA SPICER: .035

MOPAR:

8.75" x 1.75" pinion: .090

8.75" x 1.875" pinion: .020

9.25": .020

 
   
Pinion depth shims are located underneath the lower pinion bearing cone with the exception of all Dana Spicer models. Dana Spicer pinion depth shims are underneath the rear bearing cup in the housing. Dana carrier bearing preload shims are between the carrier and bearing cone. All others are on the outside of the bearing cup unless spanners are used as in the Ford 8 and 9 inch, and Mopar 8.75" and 9.25". Ford 8 and 9 inch pinion depth is regulated by shims between the pinion support and chuck or center section.

If a crush collar is used to set bearing preload, do not use until you have established pinion depth and backlash and you are satisfied with the ring gear and pinion pattern. You can simulate pinion bearing preload by tightening the pinion nut until the proper amount of drag is felt with only motor oil on the pinion bearings. The crush collar and pinion seal should be the last parts installed.