Diff Interchange Information...
Posted: Thu Sep 15, 2005 2:15 am
Some Info on changing diff ratios, and/or converting to Power Lok (limited slip).
The time had come to change the gear ratio and to add Power Lok. Anticipating such a swap, I had previously purchased a fine spline pinion yoke from Rick at Sunbeam Specialties in the US. The new yoke is required when fitting new style “Dana” gear sets, which now use a fine spline on the pinion gear, as apposed to the course Tiger spline.
I knew there was interchange between the UK Salisbury and US Dana 44, but wasn’t sure exactly what was what. The more I researched, the more confusing it became. Fortunately the solution ended out to be quite simple.
I ended up using a complete diff centre from a XJ40 Jaguar/Daimler Sovereign Double 6 (V12). This diff is actually not a true Salisbury, but of GKN manufacture (GKN is cast into the casing). Much to my surprise, the pinion and spider gear (axel) spline count was identical, making it a complete bolt in proposition. And the bonus and biggest surprise of all, was the ratio was even correct! (3.5) The new fine spline yoke purchased for the conversion ended out not to be needed after all.
That said, a few minor modifications are necessary. The Jag pinion gear has a spigot on the end of it, which mates to the unique Jaguar flexible drive shaft coupling. This is easily cut off on a matter of seconds.
The second and most important thing is that you need a new spider gear cross pin block. I’m not sure of the correct terminology, but it’s the piece that holds the spider gear cross pins in the centre of the hemisphere. The secondary purpose of this part, is apparently to act as a stop to locate the axels outwards, which the common independent Jaguar - which uses drive flanges – does not use and is missing.
These “blocks” differ dependant on application, and are where most of the confusion comes from. The Jag independent Power Lok (no axels, uses flanges), the standard Tiger non-Power Lok (axel), and the Jaguar Power Lok (axel) all differ. I used one out of a fixed axel MK2 Jaguar that fortunately just happened to be lying around.
Curiously the Jaguar pinion gear uses a thicker stem than the Tiger, but all else is compatible. If using the Jaguar gears (which I did) it is necessary to use a different pinion bearing with the appropriate larger inner diameter. The alternative is to use the US Dana 44 gears, with the before mentioned fine spline conversion yoke.
Hopefully this is of some help to someone.
The time had come to change the gear ratio and to add Power Lok. Anticipating such a swap, I had previously purchased a fine spline pinion yoke from Rick at Sunbeam Specialties in the US. The new yoke is required when fitting new style “Dana” gear sets, which now use a fine spline on the pinion gear, as apposed to the course Tiger spline.
I knew there was interchange between the UK Salisbury and US Dana 44, but wasn’t sure exactly what was what. The more I researched, the more confusing it became. Fortunately the solution ended out to be quite simple.
I ended up using a complete diff centre from a XJ40 Jaguar/Daimler Sovereign Double 6 (V12). This diff is actually not a true Salisbury, but of GKN manufacture (GKN is cast into the casing). Much to my surprise, the pinion and spider gear (axel) spline count was identical, making it a complete bolt in proposition. And the bonus and biggest surprise of all, was the ratio was even correct! (3.5) The new fine spline yoke purchased for the conversion ended out not to be needed after all.
That said, a few minor modifications are necessary. The Jag pinion gear has a spigot on the end of it, which mates to the unique Jaguar flexible drive shaft coupling. This is easily cut off on a matter of seconds.
The second and most important thing is that you need a new spider gear cross pin block. I’m not sure of the correct terminology, but it’s the piece that holds the spider gear cross pins in the centre of the hemisphere. The secondary purpose of this part, is apparently to act as a stop to locate the axels outwards, which the common independent Jaguar - which uses drive flanges – does not use and is missing.
These “blocks” differ dependant on application, and are where most of the confusion comes from. The Jag independent Power Lok (no axels, uses flanges), the standard Tiger non-Power Lok (axel), and the Jaguar Power Lok (axel) all differ. I used one out of a fixed axel MK2 Jaguar that fortunately just happened to be lying around.
Curiously the Jaguar pinion gear uses a thicker stem than the Tiger, but all else is compatible. If using the Jaguar gears (which I did) it is necessary to use a different pinion bearing with the appropriate larger inner diameter. The alternative is to use the US Dana 44 gears, with the before mentioned fine spline conversion yoke.
Hopefully this is of some help to someone.