Hopefully someone has been down this path before. I am rebuilding the diff from my 89 XJS V12 and have just bought a complete rear from an XJ40 so I was told. It has 3.58 gears and powerlok hemisphere and its a 15HU. Price was right $39.00 so I even if it is totally useless not a lot was outlaid.

My question is the pinion yoke has 3 bolts and a rubber wobbly mount, does anyone know if this is compatible with the older 4HU units or will I have to modify my drive shaft mount?

cheers
Warren

 

warrjon,, i dont know if this will help?

on mine,78 xjs with a 700R4 trans, to simplyfy things i went to a chevy output driveshaft yoke, and used a diff yoke for a chevy truck, on an Aluminum drivshaft ,with Heavy duty U-joints.

just a single piece driveshaft, works great ,no vibration! light weight!

OH my gears were from a Jeep, Dana 44.

 

Yeah I was looking at that, if this fails then I will go down that path.

I spoke to a Jag diff guy yesterday he said if I cut the snout off the XJ40 pinion it will fit the XJS housing, so hopefully it should be a simple matter of swapping the hemisphere and pinion. Sounds easy- bugger it will turn to hell in a hand basket.

 

damn you stole that diff.
I have a brand new with powerlock and 3.58 part number jlm-011624-01 maybe I can find a buyer. I need some room

 

Yeah I was lucky with this one. Maybe one of the XJS guys would be interested as you can definitely put the 15HU internals into the 4HU.

Update for the next person who tries to invent the wheel - the internals from the 15HU will go into the 4HU. The pinion is different - it has a snout which needs to be cut off and the pinion nut and thread are bigger. To make it fit the original Jag tailshaft a spacer needs to go between the yoke and tailshaft or the pinion nut needs to be ground thinner.

cheers
Warren