Rear Salisbury Axle.

After destroying the Rear Ring & Pinion in Moab last September it was decided to beef up the rear end by installing a Salisbury Diff and axle combination.  A used Salisbury was bought form Canada being a ex Military surplus item. The casing was actually originally set up for drum brakes however we will be installing Disks.

The above 2 pictures show the condition of the axle / diff casing after it has been sand blown and cleaned up.

Unfortunately the casing was not perfect and did not allow easy fitment of the new ARB locker and ring and pinion housing which meant that we needed to "tidy up" the internals with the angle grinder.

The above shows me fitting the 4.11 Ring gear to the ARB locker unit

Fitment of the pinion gears to the housing required new bearings and some trial and error fitment of shims to get things aligned correctly. This process is required to get the backlash set correctly. The backlash should be approximately; 0.02 to 0.025mm. Amazingly Keith actually achieved this from feel alone using his gauge to verify the setting.

Fitment and alignment of the Ring gears to the pinion. The final position of the pinion gear mated to the Ring gear is achieved / verified using the Gear Contact Pattern method. When checking this looking at the Drive side Heal to Toe the optimum pattern has the pattern centered on the tooth. There should be some clearance between the pattern and the top of the tooth. On the Coast side Toe to Heal the desirable pattern should be centered on the tooth but can be slightly toward the Ttoe. The should also be some clearance between the pattern and the top of the tooth. The pictures above are hard to see but I think we [read Keith] got if fairly dead on.

The Salisbury is modified from stock Rover form by adding custom Stub axles specified by and made for Rovertracks that allow the 35 spline 1.5" axle shafts to slip through with plenty of clearance. This is one of the most costly aspects of this type of conversion. The new stub axle is shown above. The 2nd picture shows the new component on the left and the stock unit on the right. The 3rd and 4th pictures above give you an appreciation for the extra room gained that is needed to run the 35 spline axle.

To maintain the factory hubs, the hubs were machined to allow for the use of much larger spindle bearings. This modification can be provided for either early RR/D110 hubs or Disco/D90/RR hubs. See the first picture below to view the machined out hub section.

To keep up with the increased strength of components, larger drive flange bolts are being employed. The standard bolt size is 10 mm the new bolt size is 7/16-20. The two comparisons can be seen in the right hand picture above. Obviously the new bolt will not be as long as that shown in the picture but I did not have the actual length bolt available when taking the photo. The actual diameter size is however accurate. To allow the use of the large bolts the factory hubs were drilled out then tapped as per the 2nd and 3rd pictures above. Yes that's me actually doing some work for once.

Modifications for a front Salisbury axle are also in the works. Let us know if you are interested.

The series of pictures below show the fitting of the pieces as discussed above.

Modified disc brake caliper brackets [bottom row last picture above] are used to affix the
rear calipers. 

The above shows the unit together.

New Axle on left, standard axle on right. The new axles are a whopping 1 1/2 inches in diameter.

The custom fit axles are made from premium quality, alloy steel that is forged in purpose built tooling then induction heat treated to optimize torsional strength, and then 100% magnafluxed. The 35 spline axle is rated at- 9,600 ft. lbs. (per axle). IF you compare this with standard axles on Land Rovers which are 24 spline the improvement is unquestionable. Keith at Rovertracks can custom order axles for virtually any configuration you want. See my parts page for more details.

Seen above is the tapping of an air line access hole to bring the air line in for the ARB Air Lockers.

Now for the fun stuff. Before fitting the new axle casing, diff and axles we had to remove the existing set up. This involved disconnecting the trailing arms, A- Arm, shocks and springs. The drive shaft had already been removed from when I broke the Ring & Pinion Gears. We also disconnected the brake calipers and brake lines. These were tired up out of the way for re-fitment to the new unit. You know that you are having fun when your wife comes in and says "Oh my god, what are your doing?????" When she saw the rear of the car just hanging there with no rear end drive line at all. Luckily this is a fairly easy process with everything just unbolting. The main concern here is to ensure that the vehicle is properly supported on jack stands so that it cannot fall off when you are working underneath.

After removing the real axle we took off the brake disks and moved them across to the new axle set up. This involved fitment of new wheel bearings and seals and connecting the brake disk to the modified wheel hut as per that shown above. You can see from the first picture just above that the wheel hub nuts are of a different configuration to that normally supplied on Land Rovers. This is quite a good set up as the locking washer works extremely well. The major problem is that the hub nut socket is not a common size configuration. Also you can note that the stub axle set up is flush with the outside of the Hub unlike many of the standard Land Rover set ups. This allows for the fitment of the Rovertracks extreme duty axles without any spacers and presents a far more attractive result.

Once things are apart the re-fitment process can take place. First of all we fitted the A Arm then the springs with the bottom spring retainers. The hardest part of refitting was attaching the trailing arms. These were only fitted temporarily so that we could properly position the new extreme duty trailing arms once the rear end was back together. Since the new axle naturally tips due to the front weighting of the differential, positioning the axles to allow the trailing arms to be inserted took the most time. It was a process of jack up the rear and then man handle the axle casing until the arm slipped in. Then the shocks were reconnected followed by the diff breather and then the brake calipers and brake lines. We have not yet connected the drive shaft as the u joint set up must be changed. Unfortunately the unit that comes with the upgraded Ring & Pinion does not attach to the standard Land rover configuration.

To finish off the diff / axle diff, a cover from Bluetorch Fabworks was purchased. We compared several and whilst I really liked the look and make of the Crane option, at an $100 extra [you need to look around for pricing] I could not justify the expense of the Crane version.

The following is from their website:

When you see them up close you get a real appreciation for how dam thick and strong they are. I doubt I will have any problems with breakage. The only major problem we stuck with it was that the air line for the ARB did not fit well under the cover and needed to be bent out of the way. Also since these are made for Dana 60 Axles the bolts supplied were wrong and we had to purchase new ones to fit the Salisbury set up.

More detailed information and more pictures to follow next week. I will post some finished pictures in 2 weeks once we finish putting it together and fit it to the Discovery along with the heavy duty diff protector. 

The Discovery also has the following:

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