The Triumph 2000 / 2500 / 2·5 Register Forum

Hello there,

Trying to understand if the diff I have is 3.7 or 3.4, I understand 3.7 would be 2000 & 3.4 would be 2500

Stamped on the outside casing is MBB6167 and on the surface where the back place meets the diff is M 3 4 ( I know that would suggest 3.4 but want to make sure before getting all the seals done etc.)

Anyone.

Thanks
Sal

Have a read of post 4. on this thread Sal - https://triumph2000register.co.uk/phpBB ... =34&t=6952

Ian

Thank Ian, but still a bit of a conundrum!

I was informed once that yellow paint on the output shaft was 2000 and red was 2500 but I’m not sure that rings true now.

I think as it’s stamped M 3 4 on the back plate casing I’ll assume it’s a 3.4 (2500) just a shame you can’t tell for certain from the cereal number (MBB6167)

Sal wrote: Sun May 28, 2023 8:00 am Thank Ian, but still a bit of a conundrum!

I was informed once that yellow paint on the output shaft was 2000 and red was 2500 but I’m not sure that rings true now.

I think as it’s stamped M 3 4 on the back plate casing I’ll assume it’s a 3.4 (2500) just a shame you can’t tell for certain from the cereal number (MBB6167)

You can count the rotations to be sure Sal

dont search for colors or markings as you cant be 100% sure:

copy&paste (and correted) from above link:

rotate both output shaft flanges (driveshaft flange) simultaniously one complete revolution*, and count the number of turns of the input flange (propshaft flange). If it turns just over 4 complete turns it is a 4.11:1, and if it turns nearly 3 3/4 turns it is a 3.7:1 diff....
Something to mark the rotating flange will help to count the turns more accurately.

*if the diff is still fitted to the car, lift the rear of the car. if you do it at home, lay unterneeth the car on you back, with feet facting towards front, and turn both wheels simultaniously.