thank you ! i am not sure how to add pix yet but i can try and supply some info ......it has 2 tags on the cover .one says 46/13. one says 7.5...it also has a casting number on it next to the lower drain plug that says. C4HU-004-25 .....next to that looks like a logo that seems to be a upper case S inside a upper case B. .....how do i post pix?

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Is that an aluminum case?

Jim

Welcome to the forum!!!  that looks like the basic Salisbury differential.  46/13 is the gear ratio which makes it a 3.54:1  As to the year I would need to see more parts.

Last edited by Daze (3/05/2012 8:22 pm)

yep that is how Jag does it, rather than putting the actual ratio they put the ring and pinion gear tooth counts.

looks like your basic XJ6/12 or XJS rear end.  As long as the hubs are not the spinner type than it is probably not an XKE rear end.  Good news is with the exception of the drive axles (shorty axle that slide in to the splines of the carrier , bolts to the side of the case and attached the carrier to the stub axle) all the XJ6/12 and XJS rear ends use the same seals bearings and other parts.

As long as it is not an XKE unit (which I don't think it is) all the parts are the same regardless of year except the above mentioned drive axles.  If it uses ball bearings on the drive axles it is a 72 or older (series I)  if it uses two sets of tapered roller bearings on the drive axles it is a 72 or newer.  (series II or III)  Given the gear ratio it is not likely a series III as most of those were 2.88:1 and 3.33:1 (or so not sure the exact ratios of the top of my head other than a 2.8 something and a 3.3 something   ).  As to what the case is made of stick a refrigerator magnet to it.  If it sticks its steel, if not aluminum.

no not the stub axles, I mean the drive axle bearings on the other end of the half shaft.  the drive axles are the parts bolted to the differential by 5 bolts.  They have 19 splines and slide in to the differential carrier.  You have to unbolt the 5 bolts on the outside of the differential and pull the drive axle out to determine the bearing type.

I am glad it is not aluminum.  yes it would have been cool and lighter had it been aluminum, but my concern was it was the exact same shape and design as the iron case and usually when they go from iron to aluminum you get more reinforcement to make up for the strength differences.

The only place I know of that was selling modified hubs was CWI and they are no longer in business.  The more material you remove the weaker you make the hub so you want to keep it to a minimum.  I removed the top edge of my hubs (for clearance not aesthetics) and I did it with a cut off wheel and my angle grinder.  it was a piece of cake.

The only paint on my IRS is on the differential.  the rest is all powder coated.  To cut the lip off I put a piece of masking tape from one side to the other and then just used a cut off wheel.