An Axle Alternative for British Sports Cars: The Venerable "Dana 44"
(originally published in British V8 Newsletter, Volume XI Issue 2, May 2003)by: Dan Lagrou
The Dana 44 axle was installed in many different vehicles starting in the early 50's. Jeeps used them for over 40 years, Chevrolet used them in the Corvettes from '80 - '82, Ford used them in the Thunderbirds in '55 & '56 and International used them in the Scouts and pick-ups from '65 - '80. 17 different ratios from 2.87 to 5.89 were available. These axles had 30 splines with a minimum diameter of 1.240", in comparison to the 9" Ford axle that has 28 splines and a minimum diameter of 1.120".
In this article I will concentrate mostly on the Jeep Mail Delivery Truck built in the late 60's
to about 1980. They were known as DJ-5's or Jeep Dispatchers. These Jeeps actually had 3 different
axles but only 1 is acceptable for use in a MGB. The first, or earliest, axle is 49 inches from
wheel mounting surface (flange to flange) and the pinion is offset about 1 1/2" to the right. This
axle is too narrow and has too much pinion offset. All of these that I have seen were 3.73:1
positraction.
The second one is the 52 inch axle which is ok on the width but this one also has too much pinion offset for a MG and will cause the driveshaft to interfere with the side of the tunnel. I've only seen this axle in a 3.07:1 ratio.
The third one is a 51.5 inch (flange to flange) and only has 0.400" of an offset. This is the good one. I've seen these in a 3.07 and a 3.73 ratio, some with positraction and some without. Some early 1970's CJ-5, CJ-7 and Jeepster Commandos may have the 51.5 inch axle as well. The next thing to do is measure and identify the 51.5" axle.
Before going to the bone yard cut a piece of wood precisely to 44.5" long. Place the wood between the brake backing plates as shown. The Dana 44 axle flange is quite distinctive and can be identified from 50 ft away. If it fits and looks like these photographs, take it home!
The second one is the 52 inch axle which is ok on the width but this one also has too much pinion offset for a MG and will cause the driveshaft to interfere with the side of the tunnel. I've only seen this axle in a 3.07:1 ratio.
The third one is a 51.5 inch (flange to flange) and only has 0.400" of an offset. This is the good one. I've seen these in a 3.07 and a 3.73 ratio, some with positraction and some without. Some early 1970's CJ-5, CJ-7 and Jeepster Commandos may have the 51.5 inch axle as well. The next thing to do is measure and identify the 51.5" axle.
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Before going to the bone yard cut a piece of wood precisely to 44.5" long. Place the wood between the brake backing plates as shown. The Dana 44 axle flange is quite distinctive and can be identified from 50 ft away. If it fits and looks like these photographs, take it home!
Once you get it home, disassemble the rear end and machine the axle shafts as shown. One of the
original wheel stud holes must be plugged and brazed. Then the 4.5" x 4 wheel pattern can be drilled
as shown. At this point, a decision must be made as to whether you are going to use disc brakes or
drum brakes. If drum brakes are going to be used, it's doubtful all of the original hardware can be
found. Ford produces a 10" x 2" drum brake kit that can be purchased from Currie Enterprises, Moser
Engineering or John's Industries. The brake backing plate center hole and the mounting holes must be
altered and the drum has to be re-drilled for the 4 on 4.5" pattern. A competent machinist on a
Bridgeport type mill can do this.
If rear disc brakes are preferred, Wilwood makes a kit for late model Mustangs which are designed for 4 lug wheels. This kit has an internal expanding parking brake system that operates on the inside of the rotor "hat". This design is much better than the mechanical caliper, which clamps on the disc. The Mustang rotors are drilled for 4 on 4.25" pattern. It's a simple Bridgeport job to drill 4 additional holes on the 4.5" pattern to fit MG's. The Wilwood backing plate with parking brake assembly is a little more difficult to modify but turns out exceptionally nice. The center hole must be enlarged slightly, a 1/8" thick spacer ring has to be made for the bearing, and the mounting holes must be relocated on the backing plate for attachment. The backing plate is difficult to assemble to the axle as the shoes, springs, etc. must be on before assembly. It gets very "busy" behind the axle flange as you can see. The last thing to do is to reduce the thickness of the caliper-mounting lug by 0.080" to get the caliper centered over the rotor.
Disclaimer: This page was researched and written by Dan Lagrou. Views expressed are those of the authors, and are provided without warrantee or guarantee. Apply at your own risk.
If rear disc brakes are preferred, Wilwood makes a kit for late model Mustangs which are designed for 4 lug wheels. This kit has an internal expanding parking brake system that operates on the inside of the rotor "hat". This design is much better than the mechanical caliper, which clamps on the disc. The Mustang rotors are drilled for 4 on 4.25" pattern. It's a simple Bridgeport job to drill 4 additional holes on the 4.5" pattern to fit MG's. The Wilwood backing plate with parking brake assembly is a little more difficult to modify but turns out exceptionally nice. The center hole must be enlarged slightly, a 1/8" thick spacer ring has to be made for the bearing, and the mounting holes must be relocated on the backing plate for attachment. The backing plate is difficult to assemble to the axle as the shoes, springs, etc. must be on before assembly. It gets very "busy" behind the axle flange as you can see. The last thing to do is to reduce the thickness of the caliper-mounting lug by 0.080" to get the caliper centered over the rotor.
Disclaimer: This page was researched and written by Dan Lagrou. Views expressed are those of the authors, and are provided without warrantee or guarantee. Apply at your own risk.
