Big Saloon Diff Number..

[Dolomite]

Hi Forumists,

The diff on my T-2000 MK1 is numbered MEC25826.  Nothing really strange about most of that, but what does the letter 'C' stand for..?  No mention of this in any litterature that I posess.

 

Helge Rorvik

Norway

[Nick Jones]

Hi,

 

Don't know the answer....... ME means that it is from and earlyish (pre '74) Mk2 2000.  Not seen an extra letter there before.  Ratio most likely 4.11:1 but could possibly be 3.7:1 as these were fitted to cars with auto box.  

 

Nick

[michaeljf]

Hello, long time but...I have two spare diffs, one (from a MK2 2500 P.I. sedan which had an auto box) MG prefix the other also has an MG prefix. Oh, and the one in the TR6 has a CD prefix. Regards, Michael.

[Nick Jones]

MG should be ex-PI and 3.45:1

TR6 should be either CP or CR @ 3.45:1 unless CD is US spec (3.7:1)

[michaeljf]

Hello Nick, One of the MG ones came out of a PI with an auto box and 3.7:1? The CD one is in an ex US TR6 and I believe they are 3.7:1. Regards, Michael. 

[Nick Jones]

Yes, US TR6 were mostly 3.7. Didn’t know the auto PIs were 3.7…….

[michaeljf]

Hello Nick, I think I read it somewhere, will have a look also one of the TR6 racers here mentioned it. Regards, Michael.

[Nick Jones]

Hi Michael,

bit of checking suggests that all 2.5 saloon diffs, including auto are 3.45:1. 
 

The possible confusion comes from the listings for the 2000 where the auto cars have 3.7:1 instead of 4.11:1 for the manuals. The later 2000 manuals also have 3.7:1.

Certainly, in those days of 3speed autos with 1:1 top gear and no converter lock-up, it would be very unusual for a car with an auto box to be shorter geared than a manual.