Tech Articles

Rearend Conversion to Ford Drums and Axles

Drum Brake and Axle Conversion,  Volvo to Ford                            3/14/98

Parts required:

 From Ford Nine Inch Rear End, used or new --
    Axle shafts
    Outer ends of axle tube
    Brake drums
    Brake shoes
    Wheel cylinders
    Backing plate
    Adjuster and spring kit

Recommended new parts include sealed bearings, wheel cylinders, and brake shoes.  The Ford drums can be reused if within specifications after turning and as long as they are the right size to begin with.  Note that the Ford rear end comes with numerous different sizes of brake drums.  Some are compatible with the Volvo wheels and brake system,  others are not.   I originally used  10 inch drums,  1.75 inch wide, which results in a swept area of 55 sq. inches, almost exactly the same as the stock brake area. Two inch drums and shoes can also be used.   Either combination works well with the standard Volvo brake relief cylinder which equalizes pressure between the front and rear.

Operations required:
1)Remove the Volvo rear end from the car
2)Remove drums, wheel cylinders, backing plates
3)Remove axles from both rear ends
    4)Have Ford axles checked, cut to length, turned to correct spline diameter and resplined to fit gear cluster splines.  This is an opportunity to change to the later differential spline where parts such as limited slip differentials are more readily available
5)Remove differential from Volvo rear or block off axle tubes to prevent contamination
6)Remove bearings from Ford rear end if they are to be reused
7)Cut outer section from Volvo rear end tubes
8)Cut outer section from Ford Nine Inch rear end
    9)Weld Ford outer rear end section to Volvo axle tube. The Ford tube is a slip fit over most Volvo axles.  The end must be parallel and have the correct spacing for the track desired.  These measurements are crucial and must be accurate for acceptable results.  A jig should be used for welding. For racing a small amount of negative camber can be dialed in at this point.
10)Install bearings and axles
11)Install backing plate
12)Install wheel cylinders, brake shoes, adjusters, drums

We no longer offer this conversion as a kit. For the 122 and drum braked 1800s, it is usually easier to upgrade the rearend by swapping to the disc brake rearend from an 1800E or ES.