Mk2 Daimler diff conversion

Hi I’m new to this type of forum, I’m from NZ and have just purchased a Mk2 Daimler and find while cruzing the engine rpm high at 90km/hr about 3 to 3500rpm. I’ve been reading some comments about changing to a Salisbury or Dana 3.54 diff, has anyone got comments on this suggestion? how easy is it to find these diffs to purchase? is it a straight forward changeover? Are you still able to use the existing axles ?

1 Like

Hi Ian welcome to the forums, where are you located in NZ?

I’m live in Cambridge

You could try either Rodney Jaguar Rover spares or Jaguar workshop, they may have a 3.8 Jag diff that would help, however from when I had my Daimler 2.5 I know that the acceleration off the line was nothing to write home about.

Salisbury diff swap is pretty straightforward, but I’m not sure about Dana. AFAIK, they were only used in later S3 XJ’s and they are IRS. Whether the diff head would fit into the Daimler axle housing is something you would need to check. As Robin says, acceleration would be seriously affected if you go to a higher ratio; 3.54 was used for auto 3.4, 3.8, and they have a lot more torque than the Daimler. According to my figures, with a 4.27 diff, 3,500rpm equals 63mph, or around 100kph, as you say. Same revs with a 3.54 = 76mph which is a big difference, but might result in pretty sluggish performance. Also need to recalibrate, or swap out speedo.

Maybe split the difference and try to find a 3.77 from an OD car?

Hi I would go for a 3.77 diff as Robin suggests
If you can get a complete axle this would be easier than trying to pull out the half shafts and springing out the diff and exchanging the crown wheel and pinion
These are Salisbury 4HA units and I believe that Dana diffs have differences
I changed a 3.54 for a 3.07 on a 3.8
You will find that you may have to pull away in D1 if your car is an auto with a BW35 box with an uprated ratio diff
Cheers Brian